Storm Prediction Center

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sun May 17 2026 Valid 172000Z - 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. ...20z Update portions of the northern MO Valley and Midwest... Earlier elevated convection across southern SD has gradually strengthened into a broader convective complex ahead of the cold front this afternoon. Current expectations are for this cluster, and additional supercells to evolve near the synoptic warm front near the SD/NE/IA and MN borders this afternoon/evening. Strongly backed low-level flow will support a tornado risk with a mixed convective mode before upscale growth into an MCS/bowing cluster this evening. Thereafter, a significant damaging wind threat with a few embedded tornadoes may evolve along the warm frontal corridor across northern IA and southern MN tonight. Damaging wind probabilities have been increased ahead of this cluster. Farther south, a CIG2 tornado area was considered across eastern NE and west-central IA given the presence of STP 4-7 possibly overlapping with discrete supercells. However, numerous storms are expected ahead of the cold front with expected interactions casting uncertainty on the longevity of the more discrete storms. Regardless, a volatile thermodynamic and kinematic environment (RAP ESRH 300-400 m2/s2) could support the threat for a higher-end tornado this evening across southeastern NE and southwestern IA should supercells remain more discrete. ...Southern OK and North TX... Modest ascent from a subtropical jet over portions of TX could support isolated thunderstorm development in the Red River Vicinity to central TX this evening. A broadly unstable environment with 70s F surface dewpoints of sufficient bulk shear for supercells could support some hail or damaging wind risk with any convection able to develop. Confidence in this scenario remains very low. ...Central High Plains... Air mass destabilization is ongoing in the post-frontal upslope flow regime across the central High Plains. Supercells remain likely with large hail, damaging gusts and a tornado or two. Eventually one or more clusters may evolve and spread eastward with an increased risk for damaging gusts tonight. Higher probabilities were shifted southward slightly to better align with the observed cold frontal position. Else where the outlook remains unchanged, see the previous discussion. ..Lyons.. 05/17/2026 .PREV DISCUSSION... /ISSUED 1129 AM CDT Sun May 17 2026/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sun May 17 2026 Valid 172000Z - 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. ...20z Update portions of the northern MO Valley and Midwest... Earlier elevated convection across southern SD has gradually strengthened into a broader convective complex ahead of the cold front this afternoon. Current expectations are for this cluster, and additional supercells to evolve near the synoptic warm front near the SD/NE/IA and MN borders this afternoon/evening. Strongly backed low-level flow will support a tornado risk with a mixed convective mode before upscale growth into an MCS/bowing cluster this evening. Thereafter, a significant damaging wind threat with a few embedded tornadoes may evolve along the warm frontal corridor across northern IA and southern MN tonight. Damaging wind probabilities have been increased ahead of this cluster. Farther south, a CIG2 tornado area was considered across eastern NE and west-central IA given the presence of STP 4-7 possibly overlapping with discrete supercells. However, numerous storms are expected ahead of the cold front with expected interactions casting uncertainty on the longevity of the more discrete storms. Regardless, a volatile thermodynamic and kinematic environment (RAP ESRH 300-400 m2/s2) could support the threat for a higher-end tornado this evening across southeastern NE and southwestern IA should supercells remain more discrete. ...Southern OK and North TX... Modest ascent from a subtropical jet over portions of TX could support isolated thunderstorm development in the Red River Vicinity to central TX this evening. A broadly unstable environment with 70s F surface dewpoints of sufficient bulk shear for supercells could support some hail or damaging wind risk with any convection able to develop. Confidence in this scenario remains very low. ...Central High Plains... Air mass destabilization is ongoing in the post-frontal upslope flow regime across the central High Plains. Supercells remain likely with large hail, damaging gusts and a tornado or two. Eventually one or more clusters may evolve and spread eastward with an increased risk for damaging gusts tonight. Higher probabilities were shifted southward slightly to better align with the observed cold frontal position. Else where the outlook remains unchanged, see the previous discussion. ..Lyons.. 05/17/2026 .PREV DISCUSSION... /ISSUED 1129 AM CDT Sun May 17 2026/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sun May 17 2026 Valid 172000Z - 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. ...20z Update portions of the northern MO Valley and Midwest... Earlier elevated convection across southern SD has gradually strengthened into a broader convective complex ahead of the cold front this afternoon. Current expectations are for this cluster, and additional supercells to evolve near the synoptic warm front near the SD/NE/IA and MN borders this afternoon/evening. Strongly backed low-level flow will support a tornado risk with a mixed convective mode before upscale growth into an MCS/bowing cluster this evening. Thereafter, a significant damaging wind threat with a few embedded tornadoes may evolve along the warm frontal corridor across northern IA and southern MN tonight. Damaging wind probabilities have been increased ahead of this cluster. Farther south, a CIG2 tornado area was considered across eastern NE and west-central IA given the presence of STP 4-7 possibly overlapping with discrete supercells. However, numerous storms are expected ahead of the cold front with expected interactions casting uncertainty on the longevity of the more discrete storms. Regardless, a volatile thermodynamic and kinematic environment (RAP ESRH 300-400 m2/s2) could support the threat for a higher-end tornado this evening across southeastern NE and southwestern IA should supercells remain more discrete. ...Southern OK and North TX... Modest ascent from a subtropical jet over portions of TX could support isolated thunderstorm development in the Red River Vicinity to central TX this evening. A broadly unstable environment with 70s F surface dewpoints of sufficient bulk shear for supercells could support some hail or damaging wind risk with any convection able to develop. Confidence in this scenario remains very low. ...Central High Plains... Air mass destabilization is ongoing in the post-frontal upslope flow regime across the central High Plains. Supercells remain likely with large hail, damaging gusts and a tornado or two. Eventually one or more clusters may evolve and spread eastward with an increased risk for damaging gusts tonight. Higher probabilities were shifted southward slightly to better align with the observed cold frontal position. Else where the outlook remains unchanged, see the previous discussion. ..Lyons.. 05/17/2026 .PREV DISCUSSION... /ISSUED 1129 AM CDT Sun May 17 2026/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sun May 17 2026 Valid 172000Z - 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. ...20z Update portions of the northern MO Valley and Midwest... Earlier elevated convection across southern SD has gradually strengthened into a broader convective complex ahead of the cold front this afternoon. Current expectations are for this cluster, and additional supercells to evolve near the synoptic warm front near the SD/NE/IA and MN borders this afternoon/evening. Strongly backed low-level flow will support a tornado risk with a mixed convective mode before upscale growth into an MCS/bowing cluster this evening. Thereafter, a significant damaging wind threat with a few embedded tornadoes may evolve along the warm frontal corridor across northern IA and southern MN tonight. Damaging wind probabilities have been increased ahead of this cluster. Farther south, a CIG2 tornado area was considered across eastern NE and west-central IA given the presence of STP 4-7 possibly overlapping with discrete supercells. However, numerous storms are expected ahead of the cold front with expected interactions casting uncertainty on the longevity of the more discrete storms. Regardless, a volatile thermodynamic and kinematic environment (RAP ESRH 300-400 m2/s2) could support the threat for a higher-end tornado this evening across southeastern NE and southwestern IA should supercells remain more discrete. ...Southern OK and North TX... Modest ascent from a subtropical jet over portions of TX could support isolated thunderstorm development in the Red River Vicinity to central TX this evening. A broadly unstable environment with 70s F surface dewpoints of sufficient bulk shear for supercells could support some hail or damaging wind risk with any convection able to develop. Confidence in this scenario remains very low. ...Central High Plains... Air mass destabilization is ongoing in the post-frontal upslope flow regime across the central High Plains. Supercells remain likely with large hail, damaging gusts and a tornado or two. Eventually one or more clusters may evolve and spread eastward with an increased risk for damaging gusts tonight. Higher probabilities were shifted southward slightly to better align with the observed cold frontal position. Else where the outlook remains unchanged, see the previous discussion. ..Lyons.. 05/17/2026 .PREV DISCUSSION... /ISSUED 1129 AM CDT Sun May 17 2026/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sun May 17 2026 Valid 172000Z - 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. ...20z Update portions of the northern MO Valley and Midwest... Earlier elevated convection across southern SD has gradually strengthened into a broader convective complex ahead of the cold front this afternoon. Current expectations are for this cluster, and additional supercells to evolve near the synoptic warm front near the SD/NE/IA and MN borders this afternoon/evening. Strongly backed low-level flow will support a tornado risk with a mixed convective mode before upscale growth into an MCS/bowing cluster this evening. Thereafter, a significant damaging wind threat with a few embedded tornadoes may evolve along the warm frontal corridor across northern IA and southern MN tonight. Damaging wind probabilities have been increased ahead of this cluster. Farther south, a CIG2 tornado area was considered across eastern NE and west-central IA given the presence of STP 4-7 possibly overlapping with discrete supercells. However, numerous storms are expected ahead of the cold front with expected interactions casting uncertainty on the longevity of the more discrete storms. Regardless, a volatile thermodynamic and kinematic environment (RAP ESRH 300-400 m2/s2) could support the threat for a higher-end tornado this evening across southeastern NE and southwestern IA should supercells remain more discrete. ...Southern OK and North TX... Modest ascent from a subtropical jet over portions of TX could support isolated thunderstorm development in the Red River Vicinity to central TX this evening. A broadly unstable environment with 70s F surface dewpoints of sufficient bulk shear for supercells could support some hail or damaging wind risk with any convection able to develop. Confidence in this scenario remains very low. ...Central High Plains... Air mass destabilization is ongoing in the post-frontal upslope flow regime across the central High Plains. Supercells remain likely with large hail, damaging gusts and a tornado or two. Eventually one or more clusters may evolve and spread eastward with an increased risk for damaging gusts tonight. Higher probabilities were shifted southward slightly to better align with the observed cold frontal position. Else where the outlook remains unchanged, see the previous discussion. ..Lyons.. 05/17/2026 .PREV DISCUSSION... /ISSUED 1129 AM CDT Sun May 17 2026/ ...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. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...FAR SOUTHWESTERN KANSAS...AND MUCH OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST AND SOUTHERN HIGH PLAINS... The threat of dangerous fire weather conditions is expected to continue again tomorrow (Monday) over the southern High Plains. Slight adjustments were made to the outlook areas over the Southwest and southern High Plains. The Extremely Critical was expanded very slightly eastward to include additional portions of southwest KS and much of the remainder of the OK/TX Panhandles. These changes were again made to tighten the risk gradient near the anticipated position of the dryline. Although not expected to be a factor affecting the current northern extent of the drawn risk areas, the impending cold front passage will impact any suppression efforts across northern portions of the highlighted area late on Day 2/Monday. The latest forecast guidance suggests that this front will reach southwest KS around 00Z. The Elevated area was also expanded to include much of the remainder of the state of NM and slightly more of south-central CO. Over California, much of the Sacramento Valley was again added to an Elevated risk area for Day 2/Monday. Forecast guidance indicates that north/northeasterly winds sustained at 15-25 mph will overlap 10-20% RH across northern portions of the Central Valley from just after noon local time through sunset. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0203 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected for parts of the southern High Plains tomorrow (Monday)*** A pronounced mid-level trough will advance to the central CONUS, encouraging the deepening of a surface low along the Kansas and Oklahoma borders, resulting in another day of volatile fire weather conditions behind a dryline and ahead of a surface cold front over the southern High Plains. The combination of downslope and gradient flow in the post-dryline environment will support widespread 20-30 mph sustained southwesterly surface winds amid 5-10 percent RH, necessitating Critical highlights from New Mexico to the Texas Panhandle and southwest Kansas areas. Extremely Critical highlights have also been added across portions of the Texas and Oklahoma Panhandles into far southwestern Kansas. Here guidance consensus is strongest in sustained southwesterly surface winds exceeding 30 mph amid single-digit RH. Given loaded fuels with ERCs exceeding the 95th percentile, any new or rejuvenated fire ignitions may spread at a life threateningly rapid pace. By evening, a surface cold front will sweep across the southern High Plains, approaching from the north. As such, west-southwesterly surface winds will quickly shift to northerly around 6-9 PM local time, which may result in a rapid, dangerous change in direction of forward movement to any ongoing wildfire fronts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...FAR SOUTHWESTERN KANSAS...AND MUCH OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST AND SOUTHERN HIGH PLAINS... The threat of dangerous fire weather conditions is expected to continue again tomorrow (Monday) over the southern High Plains. Slight adjustments were made to the outlook areas over the Southwest and southern High Plains. The Extremely Critical was expanded very slightly eastward to include additional portions of southwest KS and much of the remainder of the OK/TX Panhandles. These changes were again made to tighten the risk gradient near the anticipated position of the dryline. Although not expected to be a factor affecting the current northern extent of the drawn risk areas, the impending cold front passage will impact any suppression efforts across northern portions of the highlighted area late on Day 2/Monday. The latest forecast guidance suggests that this front will reach southwest KS around 00Z. The Elevated area was also expanded to include much of the remainder of the state of NM and slightly more of south-central CO. Over California, much of the Sacramento Valley was again added to an Elevated risk area for Day 2/Monday. Forecast guidance indicates that north/northeasterly winds sustained at 15-25 mph will overlap 10-20% RH across northern portions of the Central Valley from just after noon local time through sunset. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0203 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected for parts of the southern High Plains tomorrow (Monday)*** A pronounced mid-level trough will advance to the central CONUS, encouraging the deepening of a surface low along the Kansas and Oklahoma borders, resulting in another day of volatile fire weather conditions behind a dryline and ahead of a surface cold front over the southern High Plains. The combination of downslope and gradient flow in the post-dryline environment will support widespread 20-30 mph sustained southwesterly surface winds amid 5-10 percent RH, necessitating Critical highlights from New Mexico to the Texas Panhandle and southwest Kansas areas. Extremely Critical highlights have also been added across portions of the Texas and Oklahoma Panhandles into far southwestern Kansas. Here guidance consensus is strongest in sustained southwesterly surface winds exceeding 30 mph amid single-digit RH. Given loaded fuels with ERCs exceeding the 95th percentile, any new or rejuvenated fire ignitions may spread at a life threateningly rapid pace. By evening, a surface cold front will sweep across the southern High Plains, approaching from the north. As such, west-southwesterly surface winds will quickly shift to northerly around 6-9 PM local time, which may result in a rapid, dangerous change in direction of forward movement to any ongoing wildfire fronts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...FAR SOUTHWESTERN KANSAS...AND MUCH OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST AND SOUTHERN HIGH PLAINS... The threat of dangerous fire weather conditions is expected to continue again tomorrow (Monday) over the southern High Plains. Slight adjustments were made to the outlook areas over the Southwest and southern High Plains. The Extremely Critical was expanded very slightly eastward to include additional portions of southwest KS and much of the remainder of the OK/TX Panhandles. These changes were again made to tighten the risk gradient near the anticipated position of the dryline. Although not expected to be a factor affecting the current northern extent of the drawn risk areas, the impending cold front passage will impact any suppression efforts across northern portions of the highlighted area late on Day 2/Monday. The latest forecast guidance suggests that this front will reach southwest KS around 00Z. The Elevated area was also expanded to include much of the remainder of the state of NM and slightly more of south-central CO. Over California, much of the Sacramento Valley was again added to an Elevated risk area for Day 2/Monday. Forecast guidance indicates that north/northeasterly winds sustained at 15-25 mph will overlap 10-20% RH across northern portions of the Central Valley from just after noon local time through sunset. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0203 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected for parts of the southern High Plains tomorrow (Monday)*** A pronounced mid-level trough will advance to the central CONUS, encouraging the deepening of a surface low along the Kansas and Oklahoma borders, resulting in another day of volatile fire weather conditions behind a dryline and ahead of a surface cold front over the southern High Plains. The combination of downslope and gradient flow in the post-dryline environment will support widespread 20-30 mph sustained southwesterly surface winds amid 5-10 percent RH, necessitating Critical highlights from New Mexico to the Texas Panhandle and southwest Kansas areas. Extremely Critical highlights have also been added across portions of the Texas and Oklahoma Panhandles into far southwestern Kansas. Here guidance consensus is strongest in sustained southwesterly surface winds exceeding 30 mph amid single-digit RH. Given loaded fuels with ERCs exceeding the 95th percentile, any new or rejuvenated fire ignitions may spread at a life threateningly rapid pace. By evening, a surface cold front will sweep across the southern High Plains, approaching from the north. As such, west-southwesterly surface winds will quickly shift to northerly around 6-9 PM local time, which may result in a rapid, dangerous change in direction of forward movement to any ongoing wildfire fronts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...FAR SOUTHWESTERN KANSAS...AND MUCH OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST AND SOUTHERN HIGH PLAINS... The threat of dangerous fire weather conditions is expected to continue again tomorrow (Monday) over the southern High Plains. Slight adjustments were made to the outlook areas over the Southwest and southern High Plains. The Extremely Critical was expanded very slightly eastward to include additional portions of southwest KS and much of the remainder of the OK/TX Panhandles. These changes were again made to tighten the risk gradient near the anticipated position of the dryline. Although not expected to be a factor affecting the current northern extent of the drawn risk areas, the impending cold front passage will impact any suppression efforts across northern portions of the highlighted area late on Day 2/Monday. The latest forecast guidance suggests that this front will reach southwest KS around 00Z. The Elevated area was also expanded to include much of the remainder of the state of NM and slightly more of south-central CO. Over California, much of the Sacramento Valley was again added to an Elevated risk area for Day 2/Monday. Forecast guidance indicates that north/northeasterly winds sustained at 15-25 mph will overlap 10-20% RH across northern portions of the Central Valley from just after noon local time through sunset. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0203 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected for parts of the southern High Plains tomorrow (Monday)*** A pronounced mid-level trough will advance to the central CONUS, encouraging the deepening of a surface low along the Kansas and Oklahoma borders, resulting in another day of volatile fire weather conditions behind a dryline and ahead of a surface cold front over the southern High Plains. The combination of downslope and gradient flow in the post-dryline environment will support widespread 20-30 mph sustained southwesterly surface winds amid 5-10 percent RH, necessitating Critical highlights from New Mexico to the Texas Panhandle and southwest Kansas areas. Extremely Critical highlights have also been added across portions of the Texas and Oklahoma Panhandles into far southwestern Kansas. Here guidance consensus is strongest in sustained southwesterly surface winds exceeding 30 mph amid single-digit RH. Given loaded fuels with ERCs exceeding the 95th percentile, any new or rejuvenated fire ignitions may spread at a life threateningly rapid pace. By evening, a surface cold front will sweep across the southern High Plains, approaching from the north. As such, west-southwesterly surface winds will quickly shift to northerly around 6-9 PM local time, which may result in a rapid, dangerous change in direction of forward movement to any ongoing wildfire fronts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun May 17 2026 Valid 181200Z - 191200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EXTREME EASTERN NEW MEXICO...EXTREME SOUTHEASTERN COLORADO...FAR SOUTHWESTERN KANSAS...AND MUCH OF THE TEXAS AND OKLAHOMA PANHANDLES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST AND SOUTHERN HIGH PLAINS... The threat of dangerous fire weather conditions is expected to continue again tomorrow (Monday) over the southern High Plains. Slight adjustments were made to the outlook areas over the Southwest and southern High Plains. The Extremely Critical was expanded very slightly eastward to include additional portions of southwest KS and much of the remainder of the OK/TX Panhandles. These changes were again made to tighten the risk gradient near the anticipated position of the dryline. Although not expected to be a factor affecting the current northern extent of the drawn risk areas, the impending cold front passage will impact any suppression efforts across northern portions of the highlighted area late on Day 2/Monday. The latest forecast guidance suggests that this front will reach southwest KS around 00Z. The Elevated area was also expanded to include much of the remainder of the state of NM and slightly more of south-central CO. Over California, much of the Sacramento Valley was again added to an Elevated risk area for Day 2/Monday. Forecast guidance indicates that north/northeasterly winds sustained at 15-25 mph will overlap 10-20% RH across northern portions of the Central Valley from just after noon local time through sunset. ..Stearns.. 05/17/2026 .PREV DISCUSSION... /ISSUED 0203 AM CDT Sun May 17 2026/ ...Synopsis... ***Dangerous fire weather conditions are expected for parts of the southern High Plains tomorrow (Monday)*** A pronounced mid-level trough will advance to the central CONUS, encouraging the deepening of a surface low along the Kansas and Oklahoma borders, resulting in another day of volatile fire weather conditions behind a dryline and ahead of a surface cold front over the southern High Plains. The combination of downslope and gradient flow in the post-dryline environment will support widespread 20-30 mph sustained southwesterly surface winds amid 5-10 percent RH, necessitating Critical highlights from New Mexico to the Texas Panhandle and southwest Kansas areas. Extremely Critical highlights have also been added across portions of the Texas and Oklahoma Panhandles into far southwestern Kansas. Here guidance consensus is strongest in sustained southwesterly surface winds exceeding 30 mph amid single-digit RH. Given loaded fuels with ERCs exceeding the 95th percentile, any new or rejuvenated fire ignitions may spread at a life threateningly rapid pace. By evening, a surface cold front will sweep across the southern High Plains, approaching from the north. As such, west-southwesterly surface winds will quickly shift to northerly around 6-9 PM local time, which may result in a rapid, dangerous change in direction of forward movement to any ongoing wildfire fronts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun May 17 2026 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES TO THE SOUTHERN PLAINS... ...SUMMARY... Widely scattered severe thunderstorms will be possible along a cold front extending from the Great Lakes into the Ohio Valley and the southern Plains. ...Great Lakes and vicinity... An ejecting midlevel trough over the upper MS Valley early in the period will begin to phase with the northern stream while moving eastward over the Great Lakes. An associated surface cyclone will move across southern ON/QC, as a trailing cold front progresses southeastward across the OH/middle MS Valleys and into the southern Plains. Convection will likely be ongoing at the start of the period along the cold front from northwest TX and OK to the middle MS Valley and the vicinity of Lake MI. The stronger low-midlevel flow will be confined to the area closer to the Great Lakes, where some diurnal destabilization could allow an uptick in threat for wind damage and isolated large hail. ...Lower OH Valley into the southern Plains... Farther southwest, flow aloft will be weaker and convection will be tied to the slowing front and/or convective outflows from D2 convection persisting into D3. Moderate to strong buoyancy (greater to the west into TX) is expected just ahead of the front, which combined with the relatively weak wind profiles, will favor multicell clusters and line segments capable of producing occasional wind damage and isolated large hail through the afternoon. There will be some potential for an isolated supercell or two to move off the Serranias del Burro into TX where large CAPE will coincide with the cyclonic side of the subtropical jet and at least marginally sufficient vertical shear. Otherwise, the pattern will transition overnight to a weak warm advection regime atop the cool air mass, where elevated storms could produce large hail from northwest TX into southern OK. ..Thompson.. 05/17/2026 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun May 17 2026 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES TO THE SOUTHERN PLAINS... ...SUMMARY... Widely scattered severe thunderstorms will be possible along a cold front extending from the Great Lakes into the Ohio Valley and the southern Plains. ...Great Lakes and vicinity... An ejecting midlevel trough over the upper MS Valley early in the period will begin to phase with the northern stream while moving eastward over the Great Lakes. An associated surface cyclone will move across southern ON/QC, as a trailing cold front progresses southeastward across the OH/middle MS Valleys and into the southern Plains. Convection will likely be ongoing at the start of the period along the cold front from northwest TX and OK to the middle MS Valley and the vicinity of Lake MI. The stronger low-midlevel flow will be confined to the area closer to the Great Lakes, where some diurnal destabilization could allow an uptick in threat for wind damage and isolated large hail. ...Lower OH Valley into the southern Plains... Farther southwest, flow aloft will be weaker and convection will be tied to the slowing front and/or convective outflows from D2 convection persisting into D3. Moderate to strong buoyancy (greater to the west into TX) is expected just ahead of the front, which combined with the relatively weak wind profiles, will favor multicell clusters and line segments capable of producing occasional wind damage and isolated large hail through the afternoon. There will be some potential for an isolated supercell or two to move off the Serranias del Burro into TX where large CAPE will coincide with the cyclonic side of the subtropical jet and at least marginally sufficient vertical shear. Otherwise, the pattern will transition overnight to a weak warm advection regime atop the cool air mass, where elevated storms could produce large hail from northwest TX into southern OK. ..Thompson.. 05/17/2026 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun May 17 2026 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES TO THE SOUTHERN PLAINS... ...SUMMARY... Widely scattered severe thunderstorms will be possible along a cold front extending from the Great Lakes into the Ohio Valley and the southern Plains. ...Great Lakes and vicinity... An ejecting midlevel trough over the upper MS Valley early in the period will begin to phase with the northern stream while moving eastward over the Great Lakes. An associated surface cyclone will move across southern ON/QC, as a trailing cold front progresses southeastward across the OH/middle MS Valleys and into the southern Plains. Convection will likely be ongoing at the start of the period along the cold front from northwest TX and OK to the middle MS Valley and the vicinity of Lake MI. The stronger low-midlevel flow will be confined to the area closer to the Great Lakes, where some diurnal destabilization could allow an uptick in threat for wind damage and isolated large hail. ...Lower OH Valley into the southern Plains... Farther southwest, flow aloft will be weaker and convection will be tied to the slowing front and/or convective outflows from D2 convection persisting into D3. Moderate to strong buoyancy (greater to the west into TX) is expected just ahead of the front, which combined with the relatively weak wind profiles, will favor multicell clusters and line segments capable of producing occasional wind damage and isolated large hail through the afternoon. There will be some potential for an isolated supercell or two to move off the Serranias del Burro into TX where large CAPE will coincide with the cyclonic side of the subtropical jet and at least marginally sufficient vertical shear. Otherwise, the pattern will transition overnight to a weak warm advection regime atop the cool air mass, where elevated storms could produce large hail from northwest TX into southern OK. ..Thompson.. 05/17/2026 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun May 17 2026 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES TO THE SOUTHERN PLAINS... ...SUMMARY... Widely scattered severe thunderstorms will be possible along a cold front extending from the Great Lakes into the Ohio Valley and the southern Plains. ...Great Lakes and vicinity... An ejecting midlevel trough over the upper MS Valley early in the period will begin to phase with the northern stream while moving eastward over the Great Lakes. An associated surface cyclone will move across southern ON/QC, as a trailing cold front progresses southeastward across the OH/middle MS Valleys and into the southern Plains. Convection will likely be ongoing at the start of the period along the cold front from northwest TX and OK to the middle MS Valley and the vicinity of Lake MI. The stronger low-midlevel flow will be confined to the area closer to the Great Lakes, where some diurnal destabilization could allow an uptick in threat for wind damage and isolated large hail. ...Lower OH Valley into the southern Plains... Farther southwest, flow aloft will be weaker and convection will be tied to the slowing front and/or convective outflows from D2 convection persisting into D3. Moderate to strong buoyancy (greater to the west into TX) is expected just ahead of the front, which combined with the relatively weak wind profiles, will favor multicell clusters and line segments capable of producing occasional wind damage and isolated large hail through the afternoon. There will be some potential for an isolated supercell or two to move off the Serranias del Burro into TX where large CAPE will coincide with the cyclonic side of the subtropical jet and at least marginally sufficient vertical shear. Otherwise, the pattern will transition overnight to a weak warm advection regime atop the cool air mass, where elevated storms could produce large hail from northwest TX into southern OK. ..Thompson.. 05/17/2026 Read more

WW 0213 Status Updates
STATUS FOR WATCH 0213 HAS NOT BEEN ISSUED YET Read more

WW 0213 Status Updates
STATUS FOR WATCH 0213 HAS NOT BEEN ISSUED YET Read more

WW 0213 Status Updates
STATUS FOR WATCH 0213 HAS NOT BEEN ISSUED YET Read more

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