Storm Prediction Center

WW 0220 Status Updates
STATUS FOR WATCH 0220 HAS NOT BEEN ISSUED YET Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0858 AM CDT Mon May 18 2026 Valid 211200Z - 261200Z ...DISCUSSION... ...D4/Thursday - D5/Friday... On D4/Thursday, a stationary front will extend across the southern Plains and mid Mississippi Valley and east to the Carolinas. A few stronger thunderstorms may develop south of this boundary, however, the strongest upper-level flow will be displaced to the north, limiting confidence in a more organized severe threat. Moist southerly return flow will begin across the southern/central Plains into the weekend. Modest westerly flow across the dryline on D5/Friday may support some potential for severe storms. Overall, forcing for ascent will remain limited and there is low confidence in including a severe risk area at this time. ...D6/Saturday-D8/Monday... Through the end of the extended period, height rises are expected across the central US as a high amplitude ridge settles in from the west. While moisture will continue to move northward into the central/northern Plains, generally weak flow and subsidence will keep severe potential low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0858 AM CDT Mon May 18 2026 Valid 211200Z - 261200Z ...DISCUSSION... ...D4/Thursday - D5/Friday... On D4/Thursday, a stationary front will extend across the southern Plains and mid Mississippi Valley and east to the Carolinas. A few stronger thunderstorms may develop south of this boundary, however, the strongest upper-level flow will be displaced to the north, limiting confidence in a more organized severe threat. Moist southerly return flow will begin across the southern/central Plains into the weekend. Modest westerly flow across the dryline on D5/Friday may support some potential for severe storms. Overall, forcing for ascent will remain limited and there is low confidence in including a severe risk area at this time. ...D6/Saturday-D8/Monday... Through the end of the extended period, height rises are expected across the central US as a high amplitude ridge settles in from the west. While moisture will continue to move northward into the central/northern Plains, generally weak flow and subsidence will keep severe potential low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0858 AM CDT Mon May 18 2026 Valid 211200Z - 261200Z ...DISCUSSION... ...D4/Thursday - D5/Friday... On D4/Thursday, a stationary front will extend across the southern Plains and mid Mississippi Valley and east to the Carolinas. A few stronger thunderstorms may develop south of this boundary, however, the strongest upper-level flow will be displaced to the north, limiting confidence in a more organized severe threat. Moist southerly return flow will begin across the southern/central Plains into the weekend. Modest westerly flow across the dryline on D5/Friday may support some potential for severe storms. Overall, forcing for ascent will remain limited and there is low confidence in including a severe risk area at this time. ...D6/Saturday-D8/Monday... Through the end of the extended period, height rises are expected across the central US as a high amplitude ridge settles in from the west. While moisture will continue to move northward into the central/northern Plains, generally weak flow and subsidence will keep severe potential low. Read more

No watches are valid as of Mon May 18 14:02:02 UTC 2026.

MD 0769 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL ILLINOIS INTO WESTERN INDIANA
Mesoscale Discussion 0769 NWS Storm Prediction Center Norman OK 0840 AM CDT Mon May 18 2026 Areas affected...Central Illinois into western Indiana Concerning...Severe potential...Watch possible Valid 181340Z - 181545Z Probability of Watch Issuance...40 percent SUMMARY...Damaging wind potential will probably increase in parts of central Illinois/western Indiana. Depending on convective trends, a watch may be need. Timing is uncertain, however. DISCUSSION...South of a weak outflow boundary, a line of convection continues eastward this morning. Trends from CAPPI data suggest occasional intensification of updrafts. Upper 60s F dewpoints are noted in southern Illinois and will be advecting northward ahead of this activity. Surface observations also indicate relatively strong pressure rises behind the line. With filtered surface heating occurring in central Illinois, the main question with this convection will be how intense it will become and when that intensification will occur. The threat for damaging winds will probably increase over the next few hours. A watch is possible depending on convective trends. ..Wendt/Hart.. 05/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...IND...LOT...ILX...LSX...DVN... LAT...LON 38978956 38879015 38899065 39049065 39639043 40329022 40859008 41038970 41638776 41538679 40608665 39698691 39248824 38978956 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT MON MAY 18 2026 ...Severe thunderstorms expected over parts of the south-central Plains and mid Missouri Valley this afternoon and evening... * LOCATIONS... Iowa Central and Eastern Kansas Northwest Missouri Southeast Nebraska Northern Oklahoma * HAZARDS... Several tornadoes, a couple intense Scattered damaging winds, some hurricane force Widespread baseball-size hail * SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT MON MAY 18 2026 ...Severe thunderstorms expected over parts of the south-central Plains and mid Missouri Valley this afternoon and evening... * LOCATIONS... Iowa Central and Eastern Kansas Northwest Missouri Southeast Nebraska Northern Oklahoma * HAZARDS... Several tornadoes, a couple intense Scattered damaging winds, some hurricane force Widespread baseball-size hail * SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT MON MAY 18 2026 ...Severe thunderstorms expected over parts of the south-central Plains and mid Missouri Valley this afternoon and evening... * LOCATIONS... Iowa Central and Eastern Kansas Northwest Missouri Southeast Nebraska Northern Oklahoma * HAZARDS... Several tornadoes, a couple intense Scattered damaging winds, some hurricane force Widespread baseball-size hail * SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT MON MAY 18 2026 ...Severe thunderstorms expected over parts of the south-central Plains and mid Missouri Valley this afternoon and evening... * LOCATIONS... Iowa Central and Eastern Kansas Northwest Missouri Southeast Nebraska Northern Oklahoma * HAZARDS... Several tornadoes, a couple intense Scattered damaging winds, some hurricane force Widespread baseball-size hail * SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Mon May 18 2026 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/NORTHEAST KANSAS...SOUTHEAST NEBRASKA...AND FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains into the Midwest/Great Lakes... Extensive convection continues this morning from western IL into MO and far eastern KS, aided by warm/moist advection associated with a 40-50 kt southwesterly low-level jet. Gradual destabilization of the airmass downstream of this ongoing activity is expected today across the mid MS Valley and Midwest/OH Valley/Great Lakes. Some potential exists for re-intensification of one or more bowing clusters, with scattered damaging winds the main concern as low-level lapse rates gradually steepen. Somewhat less instability and more modest mid-level flow and related deep-layer shear with eastward extent into the OH Valley should induce gradual weakening with these clusters this evening. The outflow boundary from the morning convection across KS will likely play a key role in determining the northern extent of appreciable severe risk later today across the central Plains into the mid MO Valley. There is concern that this boundary's continued southward movement this morning and ongoing convection to its north may hinder/delay destabilization this afternoon ahead of the surface cold front/dryline. Still, strengthening mid-level flow and large-scale ascent associated with an ejecting shortwave trough is expected to overspread the developing warm sector across central KS into southeast NE by mid to late afternoon. Even with potential limiting factors such as outflow boundary placement and residual cloud cover, the presence of very steep lapse rates aloft (reference 12Z DDC observed sounding) and daytime heating of a rather moist low-level airmass will likely support strong to possibly extreme instability south of the cold front and east of the dryline by early afternoon. Most guidance continues to suggest that robust thunderstorm initiation will occur by 18-22Z across central/northeast KS into far southeast NE. These initial supercells should pose a threat for very large to potentially giant hail (2-4+ inches in diameter). As low-level shear gradually increases through late afternoon/early evening in tandem with a strengthening southerly low-level jet, a focused spatial/temporal corridor for strong to intense tornadoes should exist across parts of central/northeast KS into far southeast NE and northwest MO. Fairly quick upscale growth appears likely by mid to late evening as thunderstorm mergers/interactions occur, and as the cold front advances east-southeastward. Even so, a continued threat for QLCS and embedded supercell tornadoes should continue, as low-level shear will remain enhanced by a 50+ kt low-level jet. Severe/damaging winds will also become an increasing concern as convection spreads eastward in tandem with the cold front. Some severe wind threat may persist through much of the night since ample instability is forecast to exist ahead of convection, especially across KS/MO/OK. ...Southern Plains... Thunderstorm initiation along the dryline this afternoon/early evening across western OK into western north TX is more uncertain than locations farther north given expectations for more limited forcing for ascent. If/where convection does form, there is the potential for very large hail and a conditional risk for tornadoes with any persistent supercells, given the presence of steep mid-level lapse rates, strong instability, moderate deep-layer shear, and gradually increasing low-level shear this evening. But, weaker winds above 400 mb by late afternoon/evening may not be overly favorable for long-lived convection, even if it does form. ...Mid-Atlantic/Northeast... Influenced by terrain and a surface trough, isolated strong to severe thunderstorms capable of producing occasional wind damage may occur this afternoon within a moderately unstable environment. ..Gleason/Marsh.. 05/18/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Mon May 18 2026 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/NORTHEAST KANSAS...SOUTHEAST NEBRASKA...AND FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains into the Midwest/Great Lakes... Extensive convection continues this morning from western IL into MO and far eastern KS, aided by warm/moist advection associated with a 40-50 kt southwesterly low-level jet. Gradual destabilization of the airmass downstream of this ongoing activity is expected today across the mid MS Valley and Midwest/OH Valley/Great Lakes. Some potential exists for re-intensification of one or more bowing clusters, with scattered damaging winds the main concern as low-level lapse rates gradually steepen. Somewhat less instability and more modest mid-level flow and related deep-layer shear with eastward extent into the OH Valley should induce gradual weakening with these clusters this evening. The outflow boundary from the morning convection across KS will likely play a key role in determining the northern extent of appreciable severe risk later today across the central Plains into the mid MO Valley. There is concern that this boundary's continued southward movement this morning and ongoing convection to its north may hinder/delay destabilization this afternoon ahead of the surface cold front/dryline. Still, strengthening mid-level flow and large-scale ascent associated with an ejecting shortwave trough is expected to overspread the developing warm sector across central KS into southeast NE by mid to late afternoon. Even with potential limiting factors such as outflow boundary placement and residual cloud cover, the presence of very steep lapse rates aloft (reference 12Z DDC observed sounding) and daytime heating of a rather moist low-level airmass will likely support strong to possibly extreme instability south of the cold front and east of the dryline by early afternoon. Most guidance continues to suggest that robust thunderstorm initiation will occur by 18-22Z across central/northeast KS into far southeast NE. These initial supercells should pose a threat for very large to potentially giant hail (2-4+ inches in diameter). As low-level shear gradually increases through late afternoon/early evening in tandem with a strengthening southerly low-level jet, a focused spatial/temporal corridor for strong to intense tornadoes should exist across parts of central/northeast KS into far southeast NE and northwest MO. Fairly quick upscale growth appears likely by mid to late evening as thunderstorm mergers/interactions occur, and as the cold front advances east-southeastward. Even so, a continued threat for QLCS and embedded supercell tornadoes should continue, as low-level shear will remain enhanced by a 50+ kt low-level jet. Severe/damaging winds will also become an increasing concern as convection spreads eastward in tandem with the cold front. Some severe wind threat may persist through much of the night since ample instability is forecast to exist ahead of convection, especially across KS/MO/OK. ...Southern Plains... Thunderstorm initiation along the dryline this afternoon/early evening across western OK into western north TX is more uncertain than locations farther north given expectations for more limited forcing for ascent. If/where convection does form, there is the potential for very large hail and a conditional risk for tornadoes with any persistent supercells, given the presence of steep mid-level lapse rates, strong instability, moderate deep-layer shear, and gradually increasing low-level shear this evening. But, weaker winds above 400 mb by late afternoon/evening may not be overly favorable for long-lived convection, even if it does form. ...Mid-Atlantic/Northeast... Influenced by terrain and a surface trough, isolated strong to severe thunderstorms capable of producing occasional wind damage may occur this afternoon within a moderately unstable environment. ..Gleason/Marsh.. 05/18/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Mon May 18 2026 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/NORTHEAST KANSAS...SOUTHEAST NEBRASKA...AND FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains into the Midwest/Great Lakes... Extensive convection continues this morning from western IL into MO and far eastern KS, aided by warm/moist advection associated with a 40-50 kt southwesterly low-level jet. Gradual destabilization of the airmass downstream of this ongoing activity is expected today across the mid MS Valley and Midwest/OH Valley/Great Lakes. Some potential exists for re-intensification of one or more bowing clusters, with scattered damaging winds the main concern as low-level lapse rates gradually steepen. Somewhat less instability and more modest mid-level flow and related deep-layer shear with eastward extent into the OH Valley should induce gradual weakening with these clusters this evening. The outflow boundary from the morning convection across KS will likely play a key role in determining the northern extent of appreciable severe risk later today across the central Plains into the mid MO Valley. There is concern that this boundary's continued southward movement this morning and ongoing convection to its north may hinder/delay destabilization this afternoon ahead of the surface cold front/dryline. Still, strengthening mid-level flow and large-scale ascent associated with an ejecting shortwave trough is expected to overspread the developing warm sector across central KS into southeast NE by mid to late afternoon. Even with potential limiting factors such as outflow boundary placement and residual cloud cover, the presence of very steep lapse rates aloft (reference 12Z DDC observed sounding) and daytime heating of a rather moist low-level airmass will likely support strong to possibly extreme instability south of the cold front and east of the dryline by early afternoon. Most guidance continues to suggest that robust thunderstorm initiation will occur by 18-22Z across central/northeast KS into far southeast NE. These initial supercells should pose a threat for very large to potentially giant hail (2-4+ inches in diameter). As low-level shear gradually increases through late afternoon/early evening in tandem with a strengthening southerly low-level jet, a focused spatial/temporal corridor for strong to intense tornadoes should exist across parts of central/northeast KS into far southeast NE and northwest MO. Fairly quick upscale growth appears likely by mid to late evening as thunderstorm mergers/interactions occur, and as the cold front advances east-southeastward. Even so, a continued threat for QLCS and embedded supercell tornadoes should continue, as low-level shear will remain enhanced by a 50+ kt low-level jet. Severe/damaging winds will also become an increasing concern as convection spreads eastward in tandem with the cold front. Some severe wind threat may persist through much of the night since ample instability is forecast to exist ahead of convection, especially across KS/MO/OK. ...Southern Plains... Thunderstorm initiation along the dryline this afternoon/early evening across western OK into western north TX is more uncertain than locations farther north given expectations for more limited forcing for ascent. If/where convection does form, there is the potential for very large hail and a conditional risk for tornadoes with any persistent supercells, given the presence of steep mid-level lapse rates, strong instability, moderate deep-layer shear, and gradually increasing low-level shear this evening. But, weaker winds above 400 mb by late afternoon/evening may not be overly favorable for long-lived convection, even if it does form. ...Mid-Atlantic/Northeast... Influenced by terrain and a surface trough, isolated strong to severe thunderstorms capable of producing occasional wind damage may occur this afternoon within a moderately unstable environment. ..Gleason/Marsh.. 05/18/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Mon May 18 2026 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/NORTHEAST KANSAS...SOUTHEAST NEBRASKA...AND FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains into the Midwest/Great Lakes... Extensive convection continues this morning from western IL into MO and far eastern KS, aided by warm/moist advection associated with a 40-50 kt southwesterly low-level jet. Gradual destabilization of the airmass downstream of this ongoing activity is expected today across the mid MS Valley and Midwest/OH Valley/Great Lakes. Some potential exists for re-intensification of one or more bowing clusters, with scattered damaging winds the main concern as low-level lapse rates gradually steepen. Somewhat less instability and more modest mid-level flow and related deep-layer shear with eastward extent into the OH Valley should induce gradual weakening with these clusters this evening. The outflow boundary from the morning convection across KS will likely play a key role in determining the northern extent of appreciable severe risk later today across the central Plains into the mid MO Valley. There is concern that this boundary's continued southward movement this morning and ongoing convection to its north may hinder/delay destabilization this afternoon ahead of the surface cold front/dryline. Still, strengthening mid-level flow and large-scale ascent associated with an ejecting shortwave trough is expected to overspread the developing warm sector across central KS into southeast NE by mid to late afternoon. Even with potential limiting factors such as outflow boundary placement and residual cloud cover, the presence of very steep lapse rates aloft (reference 12Z DDC observed sounding) and daytime heating of a rather moist low-level airmass will likely support strong to possibly extreme instability south of the cold front and east of the dryline by early afternoon. Most guidance continues to suggest that robust thunderstorm initiation will occur by 18-22Z across central/northeast KS into far southeast NE. These initial supercells should pose a threat for very large to potentially giant hail (2-4+ inches in diameter). As low-level shear gradually increases through late afternoon/early evening in tandem with a strengthening southerly low-level jet, a focused spatial/temporal corridor for strong to intense tornadoes should exist across parts of central/northeast KS into far southeast NE and northwest MO. Fairly quick upscale growth appears likely by mid to late evening as thunderstorm mergers/interactions occur, and as the cold front advances east-southeastward. Even so, a continued threat for QLCS and embedded supercell tornadoes should continue, as low-level shear will remain enhanced by a 50+ kt low-level jet. Severe/damaging winds will also become an increasing concern as convection spreads eastward in tandem with the cold front. Some severe wind threat may persist through much of the night since ample instability is forecast to exist ahead of convection, especially across KS/MO/OK. ...Southern Plains... Thunderstorm initiation along the dryline this afternoon/early evening across western OK into western north TX is more uncertain than locations farther north given expectations for more limited forcing for ascent. If/where convection does form, there is the potential for very large hail and a conditional risk for tornadoes with any persistent supercells, given the presence of steep mid-level lapse rates, strong instability, moderate deep-layer shear, and gradually increasing low-level shear this evening. But, weaker winds above 400 mb by late afternoon/evening may not be overly favorable for long-lived convection, even if it does form. ...Mid-Atlantic/Northeast... Influenced by terrain and a surface trough, isolated strong to severe thunderstorms capable of producing occasional wind damage may occur this afternoon within a moderately unstable environment. ..Gleason/Marsh.. 05/18/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 AM CDT Mon May 18 2026 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/NORTHEAST KANSAS...SOUTHEAST NEBRASKA...AND FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and mid Missouri Valley. Supercells capable of producing very large to giant hail and multiple strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains into the Midwest/Great Lakes... Extensive convection continues this morning from western IL into MO and far eastern KS, aided by warm/moist advection associated with a 40-50 kt southwesterly low-level jet. Gradual destabilization of the airmass downstream of this ongoing activity is expected today across the mid MS Valley and Midwest/OH Valley/Great Lakes. Some potential exists for re-intensification of one or more bowing clusters, with scattered damaging winds the main concern as low-level lapse rates gradually steepen. Somewhat less instability and more modest mid-level flow and related deep-layer shear with eastward extent into the OH Valley should induce gradual weakening with these clusters this evening. The outflow boundary from the morning convection across KS will likely play a key role in determining the northern extent of appreciable severe risk later today across the central Plains into the mid MO Valley. There is concern that this boundary's continued southward movement this morning and ongoing convection to its north may hinder/delay destabilization this afternoon ahead of the surface cold front/dryline. Still, strengthening mid-level flow and large-scale ascent associated with an ejecting shortwave trough is expected to overspread the developing warm sector across central KS into southeast NE by mid to late afternoon. Even with potential limiting factors such as outflow boundary placement and residual cloud cover, the presence of very steep lapse rates aloft (reference 12Z DDC observed sounding) and daytime heating of a rather moist low-level airmass will likely support strong to possibly extreme instability south of the cold front and east of the dryline by early afternoon. Most guidance continues to suggest that robust thunderstorm initiation will occur by 18-22Z across central/northeast KS into far southeast NE. These initial supercells should pose a threat for very large to potentially giant hail (2-4+ inches in diameter). As low-level shear gradually increases through late afternoon/early evening in tandem with a strengthening southerly low-level jet, a focused spatial/temporal corridor for strong to intense tornadoes should exist across parts of central/northeast KS into far southeast NE and northwest MO. Fairly quick upscale growth appears likely by mid to late evening as thunderstorm mergers/interactions occur, and as the cold front advances east-southeastward. Even so, a continued threat for QLCS and embedded supercell tornadoes should continue, as low-level shear will remain enhanced by a 50+ kt low-level jet. Severe/damaging winds will also become an increasing concern as convection spreads eastward in tandem with the cold front. Some severe wind threat may persist through much of the night since ample instability is forecast to exist ahead of convection, especially across KS/MO/OK. ...Southern Plains... Thunderstorm initiation along the dryline this afternoon/early evening across western OK into western north TX is more uncertain than locations farther north given expectations for more limited forcing for ascent. If/where convection does form, there is the potential for very large hail and a conditional risk for tornadoes with any persistent supercells, given the presence of steep mid-level lapse rates, strong instability, moderate deep-layer shear, and gradually increasing low-level shear this evening. But, weaker winds above 400 mb by late afternoon/evening may not be overly favorable for long-lived convection, even if it does form. ...Mid-Atlantic/Northeast... Influenced by terrain and a surface trough, isolated strong to severe thunderstorms capable of producing occasional wind damage may occur this afternoon within a moderately unstable environment. ..Gleason/Marsh.. 05/18/2026 Read more

MD 0768 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN MISSOURI...FAR SOUTHEAST IOWA...AND WEST-CENTRAL ILLINOIS
Mesoscale Discussion 0768 NWS Storm Prediction Center Norman OK 0651 AM CDT Mon May 18 2026 Areas affected...eastern Missouri...far southeast Iowa...and west-central Illinois Concerning...Severe potential...Watch unlikely Valid 181151Z - 181315Z Probability of Watch Issuance...20 percent SUMMARY...A long lived thunderstorm cluster has shown signs of renewed updraft intensity. An isolated large hail or damaging wind gust to two will be possible this morning. A watch is currently not expected. DISCUSSION...A long lived MCS continues to move east across northern and central Missouri this morning. Recent satellite observations have shown a renewed cooling trend of cloud tops indicated of increasingly robust updrafts. This correlated to an increase in the number of taller, stronger updraft cores evident in MRMS CAPPI imagery. The renewed vigor of some of these updrafts appears tied to a slightly better environment across eastern Missouri than farther west. MUCAPE values are between 1500-2000 J/kg and objectively analyzed effective-layer shear has improved to between 30 and 40 knots. Additionally, KLSX VAD winds show strong 0-1 kilometer veering flow, with around 40-knots of shear. Upper-tropospheric winds have also improved as the area is on the northern periphery of a 60-knot 300-mb subtropical jet streak lifting northeast across Arkansas and Missouri. All this will result in the potential for some severe hail and wind this morning along the main convective edge of the MCS. Given the strength of the low-level flow, a brief tornado cannot be ruled out, especially where this MCS intersects the outflow of an earlier MCS. There is uncertainty as to the longevity of this threat. Latest CAM guidance suggests that as the low-level jet weakens later this morning, the overall severity of the MCS will weaken as well. However, given the overall character of the environment, the potential for isolated severe hail and wind will be possible over the next couple of hours. Given the sporadic nature and uncertainty regarding the longevity of the threat, a watch appears unlikely at this time, but trends are being monitored. ..Marsh/Gleason.. 05/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...DVN...SGF... LAT...LON 38389268 38909226 39539180 40379160 41129155 41219082 41089013 40568959 39768942 39108959 38648979 38159035 38019113 38129222 38389268 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 0767 CONCERNING SEVERE THUNDERSTORM WATCH 219... FOR EASTERN IOWA AND FAR SOUTHWESTERN WISCONSIN
Mesoscale Discussion 0767 NWS Storm Prediction Center Norman OK 0124 AM CDT Mon May 18 2026 Areas affected...eastern Iowa and far southwestern Wisconsin Concerning...Severe Thunderstorm Watch 219... Valid 180624Z - 180800Z The severe weather threat for Severe Thunderstorm Watch 219 continues. SUMMARY...An overall weakening trend is expected to continue with the thunderstorm complex across Iowa. If this trend continues, the severe thunderstorm watch may need to be canceled early. DISCUSSION...A formerly well organized MCS continues to move east across Iowa this morning. The environment ahead of the MCS remains quite unstable with objective analysis suggesting greater than 2000 J/kg of MUCAPE remains. Additionally, VAD profile winds from Davenport, IA, indicates strong low-level curvature within the lowest 1-km leading to 0-1km SRH in excess of 700 m2/s2 (as compared to ~300 m2/s2 on objective analyses). However, effective-layer shear decreases markedly across Iowa from west-to-east, with less than 30 knots along and ahead of the ongoing MCS. Radar observations show the effects of this as regional radar depicts a weakening MCS with a gust front pushing ahead of the main convection. Additionally, MRMS CAPPI products depict a weakening trend even within the strongest updraft cores. Given the observational trends and that the MCS continues to move farther away from the better upper-level support, this weakening trend is expected to continue through the morning. An isolated severe hail or wind report cannot be ruled out in the near term, however, the overall trend may support canceling Severe Thunderstorm Watch #219 early. ..Marsh.. 05/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MKX...DVN...ARX...DMX... LAT...LON 40619304 41299269 41679260 41989179 42509132 43169096 43699091 43729031 43269012 42349053 41539097 40639168 40619304 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon May 18 2026 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID ATLANTIC AND SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered thunderstorm activity across the Mid-Atlantic region Wednesday may pose a risk for wind and hail. Isolated thunderstorms within the upslope regime in western Texas/eastern New Mexico will also pose a risk for large hail. ...Discussion... The mid-level trough across the Great Lakes will continue to lift northward into Canada D3/Wednesday. A cold front will extend from the Northeast southward across the southern Ohio Valley into the lower Mississippi Valley and westward into southwestern Texas. Near the front across the Mid-Atlantic, sufficient deep layer shear and MLCAPE will be in place to support a few organized storms, with potential for damaging winds and large hail which supports inclusion of a Marginal Risk. Further south across western Texas, isolated to scattered afternoon thunderstorms may develop south of the front within the upslope flow regime across western Texas into eastern New Mexico. Though deep layer shear will be generally weak, moderate instability and steep low to mid-level lapse rates may support a few instances of large hail and severe winds. ..Thornton.. 05/18/2026 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon May 18 2026 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID ATLANTIC AND SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered thunderstorm activity across the Mid-Atlantic region Wednesday may pose a risk for wind and hail. Isolated thunderstorms within the upslope regime in western Texas/eastern New Mexico will also pose a risk for large hail. ...Discussion... The mid-level trough across the Great Lakes will continue to lift northward into Canada D3/Wednesday. A cold front will extend from the Northeast southward across the southern Ohio Valley into the lower Mississippi Valley and westward into southwestern Texas. Near the front across the Mid-Atlantic, sufficient deep layer shear and MLCAPE will be in place to support a few organized storms, with potential for damaging winds and large hail which supports inclusion of a Marginal Risk. Further south across western Texas, isolated to scattered afternoon thunderstorms may develop south of the front within the upslope flow regime across western Texas into eastern New Mexico. Though deep layer shear will be generally weak, moderate instability and steep low to mid-level lapse rates may support a few instances of large hail and severe winds. ..Thornton.. 05/18/2026 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon May 18 2026 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID ATLANTIC AND SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered thunderstorm activity across the Mid-Atlantic region Wednesday may pose a risk for wind and hail. Isolated thunderstorms within the upslope regime in western Texas/eastern New Mexico will also pose a risk for large hail. ...Discussion... The mid-level trough across the Great Lakes will continue to lift northward into Canada D3/Wednesday. A cold front will extend from the Northeast southward across the southern Ohio Valley into the lower Mississippi Valley and westward into southwestern Texas. Near the front across the Mid-Atlantic, sufficient deep layer shear and MLCAPE will be in place to support a few organized storms, with potential for damaging winds and large hail which supports inclusion of a Marginal Risk. Further south across western Texas, isolated to scattered afternoon thunderstorms may develop south of the front within the upslope flow regime across western Texas into eastern New Mexico. Though deep layer shear will be generally weak, moderate instability and steep low to mid-level lapse rates may support a few instances of large hail and severe winds. ..Thornton.. 05/18/2026 Read more