Storm Prediction Center

No watches are valid as of Sun May 17 18:01:02 UTC 2026.

MD 0748 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTH-CENTRAL SD INTO NORTH-CENTRAL NE
Mesoscale Discussion 0748 NWS Storm Prediction Center Norman OK 1158 AM CDT Sun May 17 2026 Areas affected...south-central SD into north-central NE Concerning...Severe potential...Watch possible Valid 171658Z - 171830Z Probability of Watch Issuance...60 percent SUMMARY...Severe thunderstorm potential will increase through early afternoon downstream from ongoing elevated convection across north-central Nebraska into south-central South Dakota. Area is being monitored for possible watch issuance. DISCUSSION...Elevated convection is ongoing at midday near the surface cold front. Inflow ahead of this storm complex is aiding in northwestward moisture transport across NE and near a modifying outflow boundary draped across north-central NE. With addition heating/moistening into early afternoon, convection developing along the southern flank of this storm complex may eventually become surface-based near the residual outflow boundary. Stronger destabilization is expected into the afternoon and this currently elevated activity may gradually become surface-based. Uncertainty remains regarding how this area of convection will ultimately evolve and how much severe potential will accompany this activity in the short term, before a more substantial risk develops further east later this afternoon. At least some large hail and damaging wind risk may accompany initial convection. Trends will be monitored and an initial watch issuance may be needed. ..Leitman/Mosier.. 05/17/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...LBF...UNR... LAT...LON 42870114 43679978 43739910 43339845 42499842 41859885 41659992 41670077 41850129 42260140 42870114 MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA... ...SUMMARY... Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska. ...Synopsis... A midlevel shortwave trough, now approaching the northern Great Basin, will move to near the Four Corners by Monday morning and then eject northeastward over northwest KS/NE during the afternoon and to the upper MS Valley by early Tuesday. This path will be along and just northwest of a stalled baroclinic zone from the central Plains into the upper MS Valley, such that the primary height falls and forcing for ascent will brush the northwest side of the surface warm sector from KS to IA. A remnant lee cyclone will persist through the afternoon near the southwest KS/OK Panhandle border, prior to a surge of the cold front in the immediate wake of the midlevel trough. Downstream from the ejecting trough, surface cyclogenesis is expected Monday night from IA into WI along a stalled front. ...KS to IA... There are a few questions surrounding the forecast for Monday afternoon/night. The northeast extent of the unstable warm sector will depend on the persistence of rain-cooled air with morning convection across IA/northern MO/northwest IL. This convection and an associated MCV could continue eastward through the day across central/northern IL, northern IN, northwest OH and Lower MI with the potential for occasional wind damage and isolated large hail. The west edge of the remnant cold pool should modify by afternoon/evening from the MO/KS/NE border area into IA, prior to thunderstorm development along the stalled front (and immediately in advance of glancing influence of the ejecting midlevel trough) 21-00z from central KS into southeast NE and western IA. Rich low-level moisture (boundary-layer dewpoints 68-72 F) is spreading northward now from TX to OK and will be established in the warm sector Monday. The moisture will reside beneath an elevated mixed layer with 8-9 C/km midlevel lapse rates and will combine with daytime heating to drive MLCAPE of 3000-4000 J/kg. Mass response to the ejecting wave and the typical evening ramp up of a low-level jet will result in favorable wind profiles/hodographs for supercells capable of producing strong-intense tornadoes and very large hail. The duration of a semi-discrete storm mode is another question, given the parallel orientation of the stalled front and the deep-layer shear vectors, in combination with focused ascent. Thus, the strong tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns into Monday night. ...OK/northwest TX... Storm development along the dryline to the south in OK/northwest TX is more uncertain given little forcing for ascent. If storms do form, there will be a conditional threat for tornadoes and very large hail. A consistent forecast weakness in the flow above 500 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. The more probable scenario remains a back-building line of storms along the cold front with occasional hail/wind Monday night. ..Thompson.. 05/17/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA... ...SUMMARY... Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska. ...Synopsis... A midlevel shortwave trough, now approaching the northern Great Basin, will move to near the Four Corners by Monday morning and then eject northeastward over northwest KS/NE during the afternoon and to the upper MS Valley by early Tuesday. This path will be along and just northwest of a stalled baroclinic zone from the central Plains into the upper MS Valley, such that the primary height falls and forcing for ascent will brush the northwest side of the surface warm sector from KS to IA. A remnant lee cyclone will persist through the afternoon near the southwest KS/OK Panhandle border, prior to a surge of the cold front in the immediate wake of the midlevel trough. Downstream from the ejecting trough, surface cyclogenesis is expected Monday night from IA into WI along a stalled front. ...KS to IA... There are a few questions surrounding the forecast for Monday afternoon/night. The northeast extent of the unstable warm sector will depend on the persistence of rain-cooled air with morning convection across IA/northern MO/northwest IL. This convection and an associated MCV could continue eastward through the day across central/northern IL, northern IN, northwest OH and Lower MI with the potential for occasional wind damage and isolated large hail. The west edge of the remnant cold pool should modify by afternoon/evening from the MO/KS/NE border area into IA, prior to thunderstorm development along the stalled front (and immediately in advance of glancing influence of the ejecting midlevel trough) 21-00z from central KS into southeast NE and western IA. Rich low-level moisture (boundary-layer dewpoints 68-72 F) is spreading northward now from TX to OK and will be established in the warm sector Monday. The moisture will reside beneath an elevated mixed layer with 8-9 C/km midlevel lapse rates and will combine with daytime heating to drive MLCAPE of 3000-4000 J/kg. Mass response to the ejecting wave and the typical evening ramp up of a low-level jet will result in favorable wind profiles/hodographs for supercells capable of producing strong-intense tornadoes and very large hail. The duration of a semi-discrete storm mode is another question, given the parallel orientation of the stalled front and the deep-layer shear vectors, in combination with focused ascent. Thus, the strong tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns into Monday night. ...OK/northwest TX... Storm development along the dryline to the south in OK/northwest TX is more uncertain given little forcing for ascent. If storms do form, there will be a conditional threat for tornadoes and very large hail. A consistent forecast weakness in the flow above 500 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. The more probable scenario remains a back-building line of storms along the cold front with occasional hail/wind Monday night. ..Thompson.. 05/17/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA... ...SUMMARY... Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska. ...Synopsis... A midlevel shortwave trough, now approaching the northern Great Basin, will move to near the Four Corners by Monday morning and then eject northeastward over northwest KS/NE during the afternoon and to the upper MS Valley by early Tuesday. This path will be along and just northwest of a stalled baroclinic zone from the central Plains into the upper MS Valley, such that the primary height falls and forcing for ascent will brush the northwest side of the surface warm sector from KS to IA. A remnant lee cyclone will persist through the afternoon near the southwest KS/OK Panhandle border, prior to a surge of the cold front in the immediate wake of the midlevel trough. Downstream from the ejecting trough, surface cyclogenesis is expected Monday night from IA into WI along a stalled front. ...KS to IA... There are a few questions surrounding the forecast for Monday afternoon/night. The northeast extent of the unstable warm sector will depend on the persistence of rain-cooled air with morning convection across IA/northern MO/northwest IL. This convection and an associated MCV could continue eastward through the day across central/northern IL, northern IN, northwest OH and Lower MI with the potential for occasional wind damage and isolated large hail. The west edge of the remnant cold pool should modify by afternoon/evening from the MO/KS/NE border area into IA, prior to thunderstorm development along the stalled front (and immediately in advance of glancing influence of the ejecting midlevel trough) 21-00z from central KS into southeast NE and western IA. Rich low-level moisture (boundary-layer dewpoints 68-72 F) is spreading northward now from TX to OK and will be established in the warm sector Monday. The moisture will reside beneath an elevated mixed layer with 8-9 C/km midlevel lapse rates and will combine with daytime heating to drive MLCAPE of 3000-4000 J/kg. Mass response to the ejecting wave and the typical evening ramp up of a low-level jet will result in favorable wind profiles/hodographs for supercells capable of producing strong-intense tornadoes and very large hail. The duration of a semi-discrete storm mode is another question, given the parallel orientation of the stalled front and the deep-layer shear vectors, in combination with focused ascent. Thus, the strong tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns into Monday night. ...OK/northwest TX... Storm development along the dryline to the south in OK/northwest TX is more uncertain given little forcing for ascent. If storms do form, there will be a conditional threat for tornadoes and very large hail. A consistent forecast weakness in the flow above 500 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. The more probable scenario remains a back-building line of storms along the cold front with occasional hail/wind Monday night. ..Thompson.. 05/17/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA... ...SUMMARY... Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska. ...Synopsis... A midlevel shortwave trough, now approaching the northern Great Basin, will move to near the Four Corners by Monday morning and then eject northeastward over northwest KS/NE during the afternoon and to the upper MS Valley by early Tuesday. This path will be along and just northwest of a stalled baroclinic zone from the central Plains into the upper MS Valley, such that the primary height falls and forcing for ascent will brush the northwest side of the surface warm sector from KS to IA. A remnant lee cyclone will persist through the afternoon near the southwest KS/OK Panhandle border, prior to a surge of the cold front in the immediate wake of the midlevel trough. Downstream from the ejecting trough, surface cyclogenesis is expected Monday night from IA into WI along a stalled front. ...KS to IA... There are a few questions surrounding the forecast for Monday afternoon/night. The northeast extent of the unstable warm sector will depend on the persistence of rain-cooled air with morning convection across IA/northern MO/northwest IL. This convection and an associated MCV could continue eastward through the day across central/northern IL, northern IN, northwest OH and Lower MI with the potential for occasional wind damage and isolated large hail. The west edge of the remnant cold pool should modify by afternoon/evening from the MO/KS/NE border area into IA, prior to thunderstorm development along the stalled front (and immediately in advance of glancing influence of the ejecting midlevel trough) 21-00z from central KS into southeast NE and western IA. Rich low-level moisture (boundary-layer dewpoints 68-72 F) is spreading northward now from TX to OK and will be established in the warm sector Monday. The moisture will reside beneath an elevated mixed layer with 8-9 C/km midlevel lapse rates and will combine with daytime heating to drive MLCAPE of 3000-4000 J/kg. Mass response to the ejecting wave and the typical evening ramp up of a low-level jet will result in favorable wind profiles/hodographs for supercells capable of producing strong-intense tornadoes and very large hail. The duration of a semi-discrete storm mode is another question, given the parallel orientation of the stalled front and the deep-layer shear vectors, in combination with focused ascent. Thus, the strong tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns into Monday night. ...OK/northwest TX... Storm development along the dryline to the south in OK/northwest TX is more uncertain given little forcing for ascent. If storms do form, there will be a conditional threat for tornadoes and very large hail. A consistent forecast weakness in the flow above 500 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. The more probable scenario remains a back-building line of storms along the cold front with occasional hail/wind Monday night. ..Thompson.. 05/17/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA... ...SUMMARY... Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska. ...Synopsis... A midlevel shortwave trough, now approaching the northern Great Basin, will move to near the Four Corners by Monday morning and then eject northeastward over northwest KS/NE during the afternoon and to the upper MS Valley by early Tuesday. This path will be along and just northwest of a stalled baroclinic zone from the central Plains into the upper MS Valley, such that the primary height falls and forcing for ascent will brush the northwest side of the surface warm sector from KS to IA. A remnant lee cyclone will persist through the afternoon near the southwest KS/OK Panhandle border, prior to a surge of the cold front in the immediate wake of the midlevel trough. Downstream from the ejecting trough, surface cyclogenesis is expected Monday night from IA into WI along a stalled front. ...KS to IA... There are a few questions surrounding the forecast for Monday afternoon/night. The northeast extent of the unstable warm sector will depend on the persistence of rain-cooled air with morning convection across IA/northern MO/northwest IL. This convection and an associated MCV could continue eastward through the day across central/northern IL, northern IN, northwest OH and Lower MI with the potential for occasional wind damage and isolated large hail. The west edge of the remnant cold pool should modify by afternoon/evening from the MO/KS/NE border area into IA, prior to thunderstorm development along the stalled front (and immediately in advance of glancing influence of the ejecting midlevel trough) 21-00z from central KS into southeast NE and western IA. Rich low-level moisture (boundary-layer dewpoints 68-72 F) is spreading northward now from TX to OK and will be established in the warm sector Monday. The moisture will reside beneath an elevated mixed layer with 8-9 C/km midlevel lapse rates and will combine with daytime heating to drive MLCAPE of 3000-4000 J/kg. Mass response to the ejecting wave and the typical evening ramp up of a low-level jet will result in favorable wind profiles/hodographs for supercells capable of producing strong-intense tornadoes and very large hail. The duration of a semi-discrete storm mode is another question, given the parallel orientation of the stalled front and the deep-layer shear vectors, in combination with focused ascent. Thus, the strong tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns into Monday night. ...OK/northwest TX... Storm development along the dryline to the south in OK/northwest TX is more uncertain given little forcing for ascent. If storms do form, there will be a conditional threat for tornadoes and very large hail. A consistent forecast weakness in the flow above 500 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. The more probable scenario remains a back-building line of storms along the cold front with occasional hail/wind Monday night. ..Thompson.. 05/17/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun May 17 2026 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... 12Z soundings across the central and southern Plains reveal steep mid-level lapse rates (8.8 deg C per km at OUN, SGF, and TOP) atop returning low-level moisture (100 mb mean mixing ratios of 15.4 and 13.1 g/kg at OUN and FWD, respectively). An MCV, from overnight storms across the Plains, is progressing into northern IL/southern MN. 12Z DVN sounding sampled a corridor of 50 kt at the base of this MCV. Morning surface analysis reveals an intricate surface pattern across the High Plains/Plains, with multiple lows within the lee troughing that extends from eastern MT through the central High Plains, a pair of warm fronts, and a residual outflow boundary across NE. The deepest surface low is over the far southern CO/KS border vicinity, with a warm front extending east-northeastward, roughly along the 70 deg F isotherm. A dryline also extends southward from this low into far west TX. Another low is in place farther north over western NE. Another warm front, this one along a sharp gradient in low-level moisture, extends northeastward from this low into far southeast SD before arcing more eastward across far southern MN and continuing across from southern WI into central Lower MI. The aforementioned outflow also extends eastward from this low across central NE. All of these boundaries will likely influence the severe potential today, combining with an emerging upper trough and moderate to strong instability, to support an expansive and complex scenario today. ...Central Plains into the Upper Midwest... Expectation is for the northern warm front mentioned in the synopsis to continue northward throughout the day while as cold front sweeps southeastward across SD and NE. Thunderstorm development is anticipated as the cold front interacts with the returning low-level moisture. Moderate to strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) will support robust thunderstorms from southeast SD through south-central NE, potentially as far south as central KS. This activity along the front will become linear quickly with damaging gusts as the primary risk. Some cell-in-line structures could support large to very large hail, particularity early in the convective cycle. Within this larger area of severe wind and hail potential, two areas appear to have a greater tornado threat. One is from northeast/east-central NE into far southeast SD. Here, the influence of a residual outflow boundary could support more discrete development ahead of the front. Any discrete development in the warm sector would likely be supercellular and capable of all hazards, including very large hail (over 2.5") and a strong tornado. The other area is where the convective line interacts with the warm front amid a strengthening low-level jet, likely far northern IA/far southern MN. Here, increased low-level shear coupled with augmentation from interaction with the front could result in significant severe gusts as well as lined-embedded QLCS tornadoes. ...Central High Plains... Thunderstorm development still appears likely across northeastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. Just how far east/northeast (into central NE) thunderstorms remains strong is a question of timing. Earlier storms could interact with the front as it moves through NE, potential leading to persistence or reintensification. However, later timing would take these storms into central NE behind the cold front. Steep mid-level lapse rates in place could still support these storms for a few hours, but the overall intensity will likely gradually decrease. ...Southern WI into Lower MI... An MCV is current progressing into northern IL/southern MN. Modest buoyancy and moderate deep-layer shear will support isolated elevated thunderstorms capable of small hail and locally strong wind gusts through early afternoon. This MCV is expected to continue northeastward into Lower MI, potentially interacting with a warm front moving north across the region this afternoon. 12Z DVN sounding sampled enhanced mid-level flow with this MCV, which could result in enough shear to support organized convection along and near the warm front later this afternoon/evening. Strong multicells and an isolated supercell or two could occur, with an attendant risk for damaging winds, hail, and perhaps a tornado. ...South-Central KS into the eastern TX Panhandle and western OK... Some guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained would likely be supercellular and capable of all severe hazards, including large to very large hail and tornadoes. Increasing low-level shear after 00Z supports a conditional risk for a strong tornado. -- No changes to these areas from the earlier 13Z Outlook -- ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Mosier/Chalmers.. 05/17/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun May 17 2026 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... 12Z soundings across the central and southern Plains reveal steep mid-level lapse rates (8.8 deg C per km at OUN, SGF, and TOP) atop returning low-level moisture (100 mb mean mixing ratios of 15.4 and 13.1 g/kg at OUN and FWD, respectively). An MCV, from overnight storms across the Plains, is progressing into northern IL/southern MN. 12Z DVN sounding sampled a corridor of 50 kt at the base of this MCV. Morning surface analysis reveals an intricate surface pattern across the High Plains/Plains, with multiple lows within the lee troughing that extends from eastern MT through the central High Plains, a pair of warm fronts, and a residual outflow boundary across NE. The deepest surface low is over the far southern CO/KS border vicinity, with a warm front extending east-northeastward, roughly along the 70 deg F isotherm. A dryline also extends southward from this low into far west TX. Another low is in place farther north over western NE. Another warm front, this one along a sharp gradient in low-level moisture, extends northeastward from this low into far southeast SD before arcing more eastward across far southern MN and continuing across from southern WI into central Lower MI. The aforementioned outflow also extends eastward from this low across central NE. All of these boundaries will likely influence the severe potential today, combining with an emerging upper trough and moderate to strong instability, to support an expansive and complex scenario today. ...Central Plains into the Upper Midwest... Expectation is for the northern warm front mentioned in the synopsis to continue northward throughout the day while as cold front sweeps southeastward across SD and NE. Thunderstorm development is anticipated as the cold front interacts with the returning low-level moisture. Moderate to strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) will support robust thunderstorms from southeast SD through south-central NE, potentially as far south as central KS. This activity along the front will become linear quickly with damaging gusts as the primary risk. Some cell-in-line structures could support large to very large hail, particularity early in the convective cycle. Within this larger area of severe wind and hail potential, two areas appear to have a greater tornado threat. One is from northeast/east-central NE into far southeast SD. Here, the influence of a residual outflow boundary could support more discrete development ahead of the front. Any discrete development in the warm sector would likely be supercellular and capable of all hazards, including very large hail (over 2.5") and a strong tornado. The other area is where the convective line interacts with the warm front amid a strengthening low-level jet, likely far northern IA/far southern MN. Here, increased low-level shear coupled with augmentation from interaction with the front could result in significant severe gusts as well as lined-embedded QLCS tornadoes. ...Central High Plains... Thunderstorm development still appears likely across northeastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. Just how far east/northeast (into central NE) thunderstorms remains strong is a question of timing. Earlier storms could interact with the front as it moves through NE, potential leading to persistence or reintensification. However, later timing would take these storms into central NE behind the cold front. Steep mid-level lapse rates in place could still support these storms for a few hours, but the overall intensity will likely gradually decrease. ...Southern WI into Lower MI... An MCV is current progressing into northern IL/southern MN. Modest buoyancy and moderate deep-layer shear will support isolated elevated thunderstorms capable of small hail and locally strong wind gusts through early afternoon. This MCV is expected to continue northeastward into Lower MI, potentially interacting with a warm front moving north across the region this afternoon. 12Z DVN sounding sampled enhanced mid-level flow with this MCV, which could result in enough shear to support organized convection along and near the warm front later this afternoon/evening. Strong multicells and an isolated supercell or two could occur, with an attendant risk for damaging winds, hail, and perhaps a tornado. ...South-Central KS into the eastern TX Panhandle and western OK... Some guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained would likely be supercellular and capable of all severe hazards, including large to very large hail and tornadoes. Increasing low-level shear after 00Z supports a conditional risk for a strong tornado. -- No changes to these areas from the earlier 13Z Outlook -- ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Mosier/Chalmers.. 05/17/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun May 17 2026 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... 12Z soundings across the central and southern Plains reveal steep mid-level lapse rates (8.8 deg C per km at OUN, SGF, and TOP) atop returning low-level moisture (100 mb mean mixing ratios of 15.4 and 13.1 g/kg at OUN and FWD, respectively). An MCV, from overnight storms across the Plains, is progressing into northern IL/southern MN. 12Z DVN sounding sampled a corridor of 50 kt at the base of this MCV. Morning surface analysis reveals an intricate surface pattern across the High Plains/Plains, with multiple lows within the lee troughing that extends from eastern MT through the central High Plains, a pair of warm fronts, and a residual outflow boundary across NE. The deepest surface low is over the far southern CO/KS border vicinity, with a warm front extending east-northeastward, roughly along the 70 deg F isotherm. A dryline also extends southward from this low into far west TX. Another low is in place farther north over western NE. Another warm front, this one along a sharp gradient in low-level moisture, extends northeastward from this low into far southeast SD before arcing more eastward across far southern MN and continuing across from southern WI into central Lower MI. The aforementioned outflow also extends eastward from this low across central NE. All of these boundaries will likely influence the severe potential today, combining with an emerging upper trough and moderate to strong instability, to support an expansive and complex scenario today. ...Central Plains into the Upper Midwest... Expectation is for the northern warm front mentioned in the synopsis to continue northward throughout the day while as cold front sweeps southeastward across SD and NE. Thunderstorm development is anticipated as the cold front interacts with the returning low-level moisture. Moderate to strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) will support robust thunderstorms from southeast SD through south-central NE, potentially as far south as central KS. This activity along the front will become linear quickly with damaging gusts as the primary risk. Some cell-in-line structures could support large to very large hail, particularity early in the convective cycle. Within this larger area of severe wind and hail potential, two areas appear to have a greater tornado threat. One is from northeast/east-central NE into far southeast SD. Here, the influence of a residual outflow boundary could support more discrete development ahead of the front. Any discrete development in the warm sector would likely be supercellular and capable of all hazards, including very large hail (over 2.5") and a strong tornado. The other area is where the convective line interacts with the warm front amid a strengthening low-level jet, likely far northern IA/far southern MN. Here, increased low-level shear coupled with augmentation from interaction with the front could result in significant severe gusts as well as lined-embedded QLCS tornadoes. ...Central High Plains... Thunderstorm development still appears likely across northeastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. Just how far east/northeast (into central NE) thunderstorms remains strong is a question of timing. Earlier storms could interact with the front as it moves through NE, potential leading to persistence or reintensification. However, later timing would take these storms into central NE behind the cold front. Steep mid-level lapse rates in place could still support these storms for a few hours, but the overall intensity will likely gradually decrease. ...Southern WI into Lower MI... An MCV is current progressing into northern IL/southern MN. Modest buoyancy and moderate deep-layer shear will support isolated elevated thunderstorms capable of small hail and locally strong wind gusts through early afternoon. This MCV is expected to continue northeastward into Lower MI, potentially interacting with a warm front moving north across the region this afternoon. 12Z DVN sounding sampled enhanced mid-level flow with this MCV, which could result in enough shear to support organized convection along and near the warm front later this afternoon/evening. Strong multicells and an isolated supercell or two could occur, with an attendant risk for damaging winds, hail, and perhaps a tornado. ...South-Central KS into the eastern TX Panhandle and western OK... Some guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained would likely be supercellular and capable of all severe hazards, including large to very large hail and tornadoes. Increasing low-level shear after 00Z supports a conditional risk for a strong tornado. -- No changes to these areas from the earlier 13Z Outlook -- ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Mosier/Chalmers.. 05/17/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun May 17 2026 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... 12Z soundings across the central and southern Plains reveal steep mid-level lapse rates (8.8 deg C per km at OUN, SGF, and TOP) atop returning low-level moisture (100 mb mean mixing ratios of 15.4 and 13.1 g/kg at OUN and FWD, respectively). An MCV, from overnight storms across the Plains, is progressing into northern IL/southern MN. 12Z DVN sounding sampled a corridor of 50 kt at the base of this MCV. Morning surface analysis reveals an intricate surface pattern across the High Plains/Plains, with multiple lows within the lee troughing that extends from eastern MT through the central High Plains, a pair of warm fronts, and a residual outflow boundary across NE. The deepest surface low is over the far southern CO/KS border vicinity, with a warm front extending east-northeastward, roughly along the 70 deg F isotherm. A dryline also extends southward from this low into far west TX. Another low is in place farther north over western NE. Another warm front, this one along a sharp gradient in low-level moisture, extends northeastward from this low into far southeast SD before arcing more eastward across far southern MN and continuing across from southern WI into central Lower MI. The aforementioned outflow also extends eastward from this low across central NE. All of these boundaries will likely influence the severe potential today, combining with an emerging upper trough and moderate to strong instability, to support an expansive and complex scenario today. ...Central Plains into the Upper Midwest... Expectation is for the northern warm front mentioned in the synopsis to continue northward throughout the day while as cold front sweeps southeastward across SD and NE. Thunderstorm development is anticipated as the cold front interacts with the returning low-level moisture. Moderate to strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) will support robust thunderstorms from southeast SD through south-central NE, potentially as far south as central KS. This activity along the front will become linear quickly with damaging gusts as the primary risk. Some cell-in-line structures could support large to very large hail, particularity early in the convective cycle. Within this larger area of severe wind and hail potential, two areas appear to have a greater tornado threat. One is from northeast/east-central NE into far southeast SD. Here, the influence of a residual outflow boundary could support more discrete development ahead of the front. Any discrete development in the warm sector would likely be supercellular and capable of all hazards, including very large hail (over 2.5") and a strong tornado. The other area is where the convective line interacts with the warm front amid a strengthening low-level jet, likely far northern IA/far southern MN. Here, increased low-level shear coupled with augmentation from interaction with the front could result in significant severe gusts as well as lined-embedded QLCS tornadoes. ...Central High Plains... Thunderstorm development still appears likely across northeastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. Just how far east/northeast (into central NE) thunderstorms remains strong is a question of timing. Earlier storms could interact with the front as it moves through NE, potential leading to persistence or reintensification. However, later timing would take these storms into central NE behind the cold front. Steep mid-level lapse rates in place could still support these storms for a few hours, but the overall intensity will likely gradually decrease. ...Southern WI into Lower MI... An MCV is current progressing into northern IL/southern MN. Modest buoyancy and moderate deep-layer shear will support isolated elevated thunderstorms capable of small hail and locally strong wind gusts through early afternoon. This MCV is expected to continue northeastward into Lower MI, potentially interacting with a warm front moving north across the region this afternoon. 12Z DVN sounding sampled enhanced mid-level flow with this MCV, which could result in enough shear to support organized convection along and near the warm front later this afternoon/evening. Strong multicells and an isolated supercell or two could occur, with an attendant risk for damaging winds, hail, and perhaps a tornado. ...South-Central KS into the eastern TX Panhandle and western OK... Some guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained would likely be supercellular and capable of all severe hazards, including large to very large hail and tornadoes. Increasing low-level shear after 00Z supports a conditional risk for a strong tornado. -- No changes to these areas from the earlier 13Z Outlook -- ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Mosier/Chalmers.. 05/17/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun May 17 2026 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... 12Z soundings across the central and southern Plains reveal steep mid-level lapse rates (8.8 deg C per km at OUN, SGF, and TOP) atop returning low-level moisture (100 mb mean mixing ratios of 15.4 and 13.1 g/kg at OUN and FWD, respectively). An MCV, from overnight storms across the Plains, is progressing into northern IL/southern MN. 12Z DVN sounding sampled a corridor of 50 kt at the base of this MCV. Morning surface analysis reveals an intricate surface pattern across the High Plains/Plains, with multiple lows within the lee troughing that extends from eastern MT through the central High Plains, a pair of warm fronts, and a residual outflow boundary across NE. The deepest surface low is over the far southern CO/KS border vicinity, with a warm front extending east-northeastward, roughly along the 70 deg F isotherm. A dryline also extends southward from this low into far west TX. Another low is in place farther north over western NE. Another warm front, this one along a sharp gradient in low-level moisture, extends northeastward from this low into far southeast SD before arcing more eastward across far southern MN and continuing across from southern WI into central Lower MI. The aforementioned outflow also extends eastward from this low across central NE. All of these boundaries will likely influence the severe potential today, combining with an emerging upper trough and moderate to strong instability, to support an expansive and complex scenario today. ...Central Plains into the Upper Midwest... Expectation is for the northern warm front mentioned in the synopsis to continue northward throughout the day while as cold front sweeps southeastward across SD and NE. Thunderstorm development is anticipated as the cold front interacts with the returning low-level moisture. Moderate to strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) will support robust thunderstorms from southeast SD through south-central NE, potentially as far south as central KS. This activity along the front will become linear quickly with damaging gusts as the primary risk. Some cell-in-line structures could support large to very large hail, particularity early in the convective cycle. Within this larger area of severe wind and hail potential, two areas appear to have a greater tornado threat. One is from northeast/east-central NE into far southeast SD. Here, the influence of a residual outflow boundary could support more discrete development ahead of the front. Any discrete development in the warm sector would likely be supercellular and capable of all hazards, including very large hail (over 2.5") and a strong tornado. The other area is where the convective line interacts with the warm front amid a strengthening low-level jet, likely far northern IA/far southern MN. Here, increased low-level shear coupled with augmentation from interaction with the front could result in significant severe gusts as well as lined-embedded QLCS tornadoes. ...Central High Plains... Thunderstorm development still appears likely across northeastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. Just how far east/northeast (into central NE) thunderstorms remains strong is a question of timing. Earlier storms could interact with the front as it moves through NE, potential leading to persistence or reintensification. However, later timing would take these storms into central NE behind the cold front. Steep mid-level lapse rates in place could still support these storms for a few hours, but the overall intensity will likely gradually decrease. ...Southern WI into Lower MI... An MCV is current progressing into northern IL/southern MN. Modest buoyancy and moderate deep-layer shear will support isolated elevated thunderstorms capable of small hail and locally strong wind gusts through early afternoon. This MCV is expected to continue northeastward into Lower MI, potentially interacting with a warm front moving north across the region this afternoon. 12Z DVN sounding sampled enhanced mid-level flow with this MCV, which could result in enough shear to support organized convection along and near the warm front later this afternoon/evening. Strong multicells and an isolated supercell or two could occur, with an attendant risk for damaging winds, hail, and perhaps a tornado. ...South-Central KS into the eastern TX Panhandle and western OK... Some guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained would likely be supercellular and capable of all severe hazards, including large to very large hail and tornadoes. Increasing low-level shear after 00Z supports a conditional risk for a strong tornado. -- No changes to these areas from the earlier 13Z Outlook -- ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Mosier/Chalmers.. 05/17/2026 Read more

MD 0747 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN WISCONSIN
Mesoscale Discussion 0747 NWS Storm Prediction Center Norman OK 1101 AM CDT Sun May 17 2026 Areas affected...southern Wisconsin Concerning...Severe potential...Watch unlikely Valid 171601Z - 171800Z Probability of Watch Issuance...20 percent SUMMARY...Isolated elevated thunderstorms may produce small hail and locally strong wind gusts through early afternoon. A severe thunderstorm watch is not currently expected. DISCUSSION...Isolated thunderstorms are ongoing across southern WI this morning near a remnant MCV from overnight convection. This feature will continue to shift east/northeast into the afternoon. Meanwhile, a quasi-stationary boundary/warm front is located near the IL/WI border. Current convection remains north of this boundary within the cooler, more stable low-level environment. Nevertheless, modest moisture and enhanced vertical shear near the MCV is supporting weak MUCAPE and enough flow for organized updrafts. Midlevel lapse rates are weak across the region, though may steepen modestly into the afternoon. Given favorable deep layer shear and stronger midlevel flow, isolated strong gusts are possible in addition to small hail. ..Leitman/Mosier.. 05/17/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...LOT...MKX...DVN...ARX... LAT...LON 43199038 43868964 44058894 44008810 43168802 42548892 42478951 42638996 42899032 43199038 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sun May 17 2026 Valid 171700Z - 181200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...SOUTHWESTERN KANSAS...AND PARTS OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF NEW MEXICO INTO THE SOUTHERN HIGH PLAINS... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SACRAMENTO VALLEY IN CALIFORNIA... The overall forecast remains on track today as the threat of dangerous fire weather continues across the southern High Plains. Slight adjustments were made to expand the northern extent of the Extremely Critical area over far northeastern NM, far southeastern CO, and southwestern KS. The latest forecast guidance indicates that the placement of the dryline remains as anticipated with the previous forecast issuance. That being said, the Extremely Critical conditions are expected to impact areas just behind the dryline, so the risk gradient was tightened across this area. Farther west, the existing Elevated area was expanded, over portions of southern UT and northern AZ, though fuels are comparatively less receptive. Even so, fire weather risk amid west-southwesterly winds of 15-25 mph combined with 10-20% minimum RHs over these regions is worth highlighting. Additionally, expect winds to quickly turn northerly behind a significant cold front sweeping across the country, which will arrive over southern UT around sunset this evening. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected across the southern High Plains today*** A deepening mid-level trough across the Rockies will support appreciable surface low intensification across the central Plains today. The combination of strong downslope flow from the Rockies, in tandem with gradient westerly flow, will support very dry and windy conditions across portions of the Southwest into the southern High Plains. With above average fuel loading of very dry grasses and holdovers from previous fires already present across the southern High Plains, the very dry and windy conditions will promote a volatile setup for rapid, dangerous wildfire spread potential. ...Southern High Plains... A dryline will sharpen along the Texas Panhandle/western Oklahoma border during the afternoon, with a very dry boundary layer expected to mix up to at least 600 mb behind the dryline, from central New Mexico into the Texas Panhandle and southwestern Kansas areas. While gradient westerly surface flow will increase through the day, downward mixing of stronger flow aloft in the post-dryline environment will support widespread 25-30 mph sustained west-southwesterly surface winds amid 5-15 percent RH. These conditions are likely across much of New Mexico to the immediate dryline vicinity, where Critical highlights have been maintained. Extremely Critical highlights have been adjusted to where guidance consensus shows the longest term overlap of the aforementioned winds/RH with loaded fuels exceeding the 95th percentile. While the sustained surface winds may fall just shy of typical Extremely Critical criteria, the combination of fuel loading and potential pre-existing holdovers of earlier fire starts suggests that a volatile landscape will be in place to support dangerous wildfire-spread potential. ...California Central Valley Region... Deep-layer north-northwesterly flow will overspread the Central Valley region as a mid-level jet streak overspreads California on the backside of an upper trough. Downslope flow from the higher terrain will support surface winds exceeding 25 mph in spots as RH dips to the 15-20 percent range. Given dry fuels, Critical highlights have been introduced to the Sacramento Valley region. Broader Elevated highlights extend into the San Joaquin Valley, where 15+ mph sustained northerly winds will overlap with 15-20 percent RH. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sun May 17 2026 Valid 171700Z - 181200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...SOUTHWESTERN KANSAS...AND PARTS OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF NEW MEXICO INTO THE SOUTHERN HIGH PLAINS... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SACRAMENTO VALLEY IN CALIFORNIA... The overall forecast remains on track today as the threat of dangerous fire weather continues across the southern High Plains. Slight adjustments were made to expand the northern extent of the Extremely Critical area over far northeastern NM, far southeastern CO, and southwestern KS. The latest forecast guidance indicates that the placement of the dryline remains as anticipated with the previous forecast issuance. That being said, the Extremely Critical conditions are expected to impact areas just behind the dryline, so the risk gradient was tightened across this area. Farther west, the existing Elevated area was expanded, over portions of southern UT and northern AZ, though fuels are comparatively less receptive. Even so, fire weather risk amid west-southwesterly winds of 15-25 mph combined with 10-20% minimum RHs over these regions is worth highlighting. Additionally, expect winds to quickly turn northerly behind a significant cold front sweeping across the country, which will arrive over southern UT around sunset this evening. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected across the southern High Plains today*** A deepening mid-level trough across the Rockies will support appreciable surface low intensification across the central Plains today. The combination of strong downslope flow from the Rockies, in tandem with gradient westerly flow, will support very dry and windy conditions across portions of the Southwest into the southern High Plains. With above average fuel loading of very dry grasses and holdovers from previous fires already present across the southern High Plains, the very dry and windy conditions will promote a volatile setup for rapid, dangerous wildfire spread potential. ...Southern High Plains... A dryline will sharpen along the Texas Panhandle/western Oklahoma border during the afternoon, with a very dry boundary layer expected to mix up to at least 600 mb behind the dryline, from central New Mexico into the Texas Panhandle and southwestern Kansas areas. While gradient westerly surface flow will increase through the day, downward mixing of stronger flow aloft in the post-dryline environment will support widespread 25-30 mph sustained west-southwesterly surface winds amid 5-15 percent RH. These conditions are likely across much of New Mexico to the immediate dryline vicinity, where Critical highlights have been maintained. Extremely Critical highlights have been adjusted to where guidance consensus shows the longest term overlap of the aforementioned winds/RH with loaded fuels exceeding the 95th percentile. While the sustained surface winds may fall just shy of typical Extremely Critical criteria, the combination of fuel loading and potential pre-existing holdovers of earlier fire starts suggests that a volatile landscape will be in place to support dangerous wildfire-spread potential. ...California Central Valley Region... Deep-layer north-northwesterly flow will overspread the Central Valley region as a mid-level jet streak overspreads California on the backside of an upper trough. Downslope flow from the higher terrain will support surface winds exceeding 25 mph in spots as RH dips to the 15-20 percent range. Given dry fuels, Critical highlights have been introduced to the Sacramento Valley region. Broader Elevated highlights extend into the San Joaquin Valley, where 15+ mph sustained northerly winds will overlap with 15-20 percent RH. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sun May 17 2026 Valid 171700Z - 181200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...SOUTHWESTERN KANSAS...AND PARTS OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF NEW MEXICO INTO THE SOUTHERN HIGH PLAINS... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SACRAMENTO VALLEY IN CALIFORNIA... The overall forecast remains on track today as the threat of dangerous fire weather continues across the southern High Plains. Slight adjustments were made to expand the northern extent of the Extremely Critical area over far northeastern NM, far southeastern CO, and southwestern KS. The latest forecast guidance indicates that the placement of the dryline remains as anticipated with the previous forecast issuance. That being said, the Extremely Critical conditions are expected to impact areas just behind the dryline, so the risk gradient was tightened across this area. Farther west, the existing Elevated area was expanded, over portions of southern UT and northern AZ, though fuels are comparatively less receptive. Even so, fire weather risk amid west-southwesterly winds of 15-25 mph combined with 10-20% minimum RHs over these regions is worth highlighting. Additionally, expect winds to quickly turn northerly behind a significant cold front sweeping across the country, which will arrive over southern UT around sunset this evening. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected across the southern High Plains today*** A deepening mid-level trough across the Rockies will support appreciable surface low intensification across the central Plains today. The combination of strong downslope flow from the Rockies, in tandem with gradient westerly flow, will support very dry and windy conditions across portions of the Southwest into the southern High Plains. With above average fuel loading of very dry grasses and holdovers from previous fires already present across the southern High Plains, the very dry and windy conditions will promote a volatile setup for rapid, dangerous wildfire spread potential. ...Southern High Plains... A dryline will sharpen along the Texas Panhandle/western Oklahoma border during the afternoon, with a very dry boundary layer expected to mix up to at least 600 mb behind the dryline, from central New Mexico into the Texas Panhandle and southwestern Kansas areas. While gradient westerly surface flow will increase through the day, downward mixing of stronger flow aloft in the post-dryline environment will support widespread 25-30 mph sustained west-southwesterly surface winds amid 5-15 percent RH. These conditions are likely across much of New Mexico to the immediate dryline vicinity, where Critical highlights have been maintained. Extremely Critical highlights have been adjusted to where guidance consensus shows the longest term overlap of the aforementioned winds/RH with loaded fuels exceeding the 95th percentile. While the sustained surface winds may fall just shy of typical Extremely Critical criteria, the combination of fuel loading and potential pre-existing holdovers of earlier fire starts suggests that a volatile landscape will be in place to support dangerous wildfire-spread potential. ...California Central Valley Region... Deep-layer north-northwesterly flow will overspread the Central Valley region as a mid-level jet streak overspreads California on the backside of an upper trough. Downslope flow from the higher terrain will support surface winds exceeding 25 mph in spots as RH dips to the 15-20 percent range. Given dry fuels, Critical highlights have been introduced to the Sacramento Valley region. Broader Elevated highlights extend into the San Joaquin Valley, where 15+ mph sustained northerly winds will overlap with 15-20 percent RH. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sun May 17 2026 Valid 171700Z - 181200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...SOUTHWESTERN KANSAS...AND PARTS OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF NEW MEXICO INTO THE SOUTHERN HIGH PLAINS... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SACRAMENTO VALLEY IN CALIFORNIA... The overall forecast remains on track today as the threat of dangerous fire weather continues across the southern High Plains. Slight adjustments were made to expand the northern extent of the Extremely Critical area over far northeastern NM, far southeastern CO, and southwestern KS. The latest forecast guidance indicates that the placement of the dryline remains as anticipated with the previous forecast issuance. That being said, the Extremely Critical conditions are expected to impact areas just behind the dryline, so the risk gradient was tightened across this area. Farther west, the existing Elevated area was expanded, over portions of southern UT and northern AZ, though fuels are comparatively less receptive. Even so, fire weather risk amid west-southwesterly winds of 15-25 mph combined with 10-20% minimum RHs over these regions is worth highlighting. Additionally, expect winds to quickly turn northerly behind a significant cold front sweeping across the country, which will arrive over southern UT around sunset this evening. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected across the southern High Plains today*** A deepening mid-level trough across the Rockies will support appreciable surface low intensification across the central Plains today. The combination of strong downslope flow from the Rockies, in tandem with gradient westerly flow, will support very dry and windy conditions across portions of the Southwest into the southern High Plains. With above average fuel loading of very dry grasses and holdovers from previous fires already present across the southern High Plains, the very dry and windy conditions will promote a volatile setup for rapid, dangerous wildfire spread potential. ...Southern High Plains... A dryline will sharpen along the Texas Panhandle/western Oklahoma border during the afternoon, with a very dry boundary layer expected to mix up to at least 600 mb behind the dryline, from central New Mexico into the Texas Panhandle and southwestern Kansas areas. While gradient westerly surface flow will increase through the day, downward mixing of stronger flow aloft in the post-dryline environment will support widespread 25-30 mph sustained west-southwesterly surface winds amid 5-15 percent RH. These conditions are likely across much of New Mexico to the immediate dryline vicinity, where Critical highlights have been maintained. Extremely Critical highlights have been adjusted to where guidance consensus shows the longest term overlap of the aforementioned winds/RH with loaded fuels exceeding the 95th percentile. While the sustained surface winds may fall just shy of typical Extremely Critical criteria, the combination of fuel loading and potential pre-existing holdovers of earlier fire starts suggests that a volatile landscape will be in place to support dangerous wildfire-spread potential. ...California Central Valley Region... Deep-layer north-northwesterly flow will overspread the Central Valley region as a mid-level jet streak overspreads California on the backside of an upper trough. Downslope flow from the higher terrain will support surface winds exceeding 25 mph in spots as RH dips to the 15-20 percent range. Given dry fuels, Critical highlights have been introduced to the Sacramento Valley region. Broader Elevated highlights extend into the San Joaquin Valley, where 15+ mph sustained northerly winds will overlap with 15-20 percent RH. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Sun May 17 13:57:01 UTC 2026.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Sun May 17 2026 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... Large-scale upper troughing over the western CONUS should further amplify today as an embedded mid-level jet and associated shortwave trough move from the West Coast to the Four Corners region through the period. A broad zone of around 40-50 kt southwesterly mid-level flow will persist today from the southern/central High Plains to the Upper Midwest, with multiple small-scale perturbations forecast to advance northeastward across these regions. At the surface, a low over western KS this morning is expected to gradually develop northeastward towards the KS/NE border vicinity this evening. A dryline trailing from this low will mix eastward through late afternoon peak heating across the southern/central High Plains. A warm front will attempt to lift northward today across NE/IA into southeast SD and parts of southern MN, while a cold front is forecast to gradually advance southeastward across the northern/central Plains through the period. ...Southern/Central Plains into the Upper Midwest... Initial thunderstorm development appears likely across eastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. By 20-22Z, additional robust convection is expected to develop along/near the cold front across north-central NE/south-central SD in a rapidly destabilizing airmass. There is still some uncertainty with how far north the warm front and related rich low-level moisture will reach across the northern Plains/Upper Midwest, especially given ongoing convection and related outflow this morning across NE/IA. Still, an increasing large hail threat remains evident with any convection that develops along/near the cold front this afternoon, as ample MUCAPE and strong deep-layer shear will support organized updrafts, including supercells initially. A strong tornado threat will exist with any of these supercells that can become/remain surface based, as low-level shear strengthens through the late afternoon/early evening. A greater threat for severe/damaging winds should develop as convection quickly grows upscale into bowing clusters this evening. The northeastward extent of this severe wind threat remains a bit uncertain, especially into southern/central MN where the warm front is forecast to reach. A risk for embedded QLCS tornadoes may continue with the surface-based portion of the cluster. Thunderstorm initiation farther south along the length of the dryline appears somewhat conditional given modest large-scale ascent. But, most guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained will pose a threat for large to very large hail and tornadoes, especially across KS where a 40-50 kt southerly low-level jet will enhance 0-1 km shear. A strong tornado appears possible this evening with any supercell that can persist, although there should be a tendency for upscale growth into a severe wind producing cluster with time as the cold front overtakes the dryline. ...Great Lakes/Lower Michigan... Recent radar and visible satellite imagery show an MCV associated with earlier convection across the central Plains is present over IA this morning. This feature is forecast to track east-northeastward today, and should approach eastern WI and Lower MI by late afternoon/early evening. Modest enhancement to the low/mid-level wind field should exist in close proximity to this MCV, and the surface warm front is expected to gradually develop northward across these regions through the day. Some intensification of convection is possible this afternoon/evening along and near the warm front, with sufficient instability and shear to support a mix of supercells and multicell clusters capable of producing damaging winds, hail, and perhaps a tornado. A Slight Risk has been added for parts of Lower MI given increased confidence in this scenario occurring. ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in a persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Gleason/Marsh.. 05/17/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Sun May 17 2026 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND MID MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are expected this afternoon into tonight across parts of the southern/central Plains to the Upper Midwest. Supercells with very large hail and strong tornadoes are possible initially this afternoon, before one or more bowing clusters leads to a greater threat for severe/damaging winds this evening. ...Synopsis... Large-scale upper troughing over the western CONUS should further amplify today as an embedded mid-level jet and associated shortwave trough move from the West Coast to the Four Corners region through the period. A broad zone of around 40-50 kt southwesterly mid-level flow will persist today from the southern/central High Plains to the Upper Midwest, with multiple small-scale perturbations forecast to advance northeastward across these regions. At the surface, a low over western KS this morning is expected to gradually develop northeastward towards the KS/NE border vicinity this evening. A dryline trailing from this low will mix eastward through late afternoon peak heating across the southern/central High Plains. A warm front will attempt to lift northward today across NE/IA into southeast SD and parts of southern MN, while a cold front is forecast to gradually advance southeastward across the northern/central Plains through the period. ...Southern/Central Plains into the Upper Midwest... Initial thunderstorm development appears likely across eastern CO this afternoon in a low-level upslope flow regime. This activity will likely become supercellular and capable of producing large to very large hail given the presence of steep mid-level lapse rates, strong deep-layer shear, and moderate instability. By 20-22Z, additional robust convection is expected to develop along/near the cold front across north-central NE/south-central SD in a rapidly destabilizing airmass. There is still some uncertainty with how far north the warm front and related rich low-level moisture will reach across the northern Plains/Upper Midwest, especially given ongoing convection and related outflow this morning across NE/IA. Still, an increasing large hail threat remains evident with any convection that develops along/near the cold front this afternoon, as ample MUCAPE and strong deep-layer shear will support organized updrafts, including supercells initially. A strong tornado threat will exist with any of these supercells that can become/remain surface based, as low-level shear strengthens through the late afternoon/early evening. A greater threat for severe/damaging winds should develop as convection quickly grows upscale into bowing clusters this evening. The northeastward extent of this severe wind threat remains a bit uncertain, especially into southern/central MN where the warm front is forecast to reach. A risk for embedded QLCS tornadoes may continue with the surface-based portion of the cluster. Thunderstorm initiation farther south along the length of the dryline appears somewhat conditional given modest large-scale ascent. But, most guidance continues to show at least isolated high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK. Any thunderstorms which can be sustained will pose a threat for large to very large hail and tornadoes, especially across KS where a 40-50 kt southerly low-level jet will enhance 0-1 km shear. A strong tornado appears possible this evening with any supercell that can persist, although there should be a tendency for upscale growth into a severe wind producing cluster with time as the cold front overtakes the dryline. ...Great Lakes/Lower Michigan... Recent radar and visible satellite imagery show an MCV associated with earlier convection across the central Plains is present over IA this morning. This feature is forecast to track east-northeastward today, and should approach eastern WI and Lower MI by late afternoon/early evening. Modest enhancement to the low/mid-level wind field should exist in close proximity to this MCV, and the surface warm front is expected to gradually develop northward across these regions through the day. Some intensification of convection is possible this afternoon/evening along and near the warm front, with sufficient instability and shear to support a mix of supercells and multicell clusters capable of producing damaging winds, hail, and perhaps a tornado. A Slight Risk has been added for parts of Lower MI given increased confidence in this scenario occurring. ...Southeast... On the western periphery of a surface high centered over the western Atlantic, diurnally maximized thunderstorm development should focus from the southern Appalachians across GA and the interior/western FL Peninsula. Even though deep-layer shear will remain weak, a favorable thermodynamic environment with steepened low-level lapse rates should support strong to pulse-severe type convection capable of producing isolated wind damage/downbursts and perhaps marginally severe hail. ...Central and North Texas/ArkLaTex/Lower Mississippi Valley... A fairly robust cap is expected to remain across the southern extent of the warm sector today, with minimal/nebulous large-scale ascent over the southern Plains. Still, some guidance suggests elevated thunderstorms may develop through peak afternoon heating across parts of northeast TX into the ArkLaTex/lower MS Valley in a persistent low-level warm advection regime. If this occurs, then isolated severe hail and damaging winds would be possible given the strong MUCAPE forecast. ...Mid-Atlantic... Mid-level ridging should build over the Mid-Atlantic through the afternoon, which should tend to suppress most convection. However, a weak mid-level perturbation noted in water vapor imagery this morning over OH may support isolated convective development this afternoon across parts of MD/PA and vicinity. The overall environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger cores that may develop. ..Gleason/Marsh.. 05/17/2026 Read more