Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS TO THE MIDWEST... ...SUMMARY... Localized damaging winds are possible across parts of the Midwest, Mid-South, and southern Great Plains on Tuesday afternoon to early evening. ...Midwest to Southern Great Plains... The upper-level pattern will be characterized by an anticyclone anchored over the Southwest and a low-amplitude trough/embedded MCVs from the Great Lakes to the Lower MO Valley. While mid-level winds will be weak to the southwest of the Great Lakes, low-probability severe gust/damaging wind potential is evident Tuesday along a convectively modulated surface front expected to arc from the Lake Erie vicinity to the Lower OH Valley and trailing into KS/OK. This should be focused during the afternoon to early evening as scattered to numerous thunderstorms form along the front, as well as on pre-existing outflows from early-day convective remnants. Rather warm boundary-layer temperatures will again support a swath of large buoyancy, which should have embedded pockets of more muted MLCAPE where morning convection decays. 12Z HREF and ML guidance signals are supportive of sporadic strong to severe gusts in wet microbursts. With weak deep-layer shear, organized clustering appears unlikely. Thus, isolated damaging winds seem plausible until convection weakens around sunset. ..Grams.. 08/18/2025 Read more

MD 1983 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN ILLINOIS AND SOUTHERN WISCONSIN
Mesoscale Discussion 1983 NWS Storm Prediction Center Norman OK 1110 AM CDT Mon Aug 18 2025 Areas affected...northern Illinois and southern Wisconsin Concerning...Severe potential...Watch possible Valid 181610Z - 181745Z Probability of Watch Issuance...60 percent SUMMARY...The damaging wind threat will increase across northern Illinois and southern Wisconsin this afternoon. DISCUSSION...An outflow boundary from overnight storms continues to move east across southern Wisconsin, far eastern Iowa, and northwestern Illinois. Storms have started to strengthen along this boundary as the boundary layer destabilizes. SPC mesoanalysis indicates some weak inhibition remains ahead of storms, but is mostly eroded farther east across southern Wisconsin and northern Illinois where temperatures have warmed into the low to mid 80s. Therefore, expect additional strengthening of the updrafts as this line moves east. Around 35 knots of effective shear (per MKX VWP) should be sufficient to sustain some damaging wind threat from these storms as they move east. A severe thunderstorm watch may need to be issued by early afternoon if storm intensity/coverage increases as anticipated. ..Bentley/Mosier.. 08/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...DVN... LAT...LON 41099073 41539031 42179019 42819014 43329016 43518894 43278777 42608770 42138757 41648753 40988759 40818877 40918984 41109050 41099073 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

WW 0599 Status Updates
STATUS FOR WATCH 0599 HAS NOT BEEN ISSUED YET Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN WI AND NORTHERN IL...AND ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Midwest today. Widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Mid MS Valley... Extensive outflow from last night's MCS currently extends from extreme southwest WI southwestward through eastern IA and north-central MO into eastern KS. This outflow has been moving quickly eastward/southeastward this morning, and this trend is expected to continue, although some slowing of its progression speed is possible over time. The downstream airmass across from southern WI and IL is characterized by dewpoints in the low to mid 70s. Mid-level lapse rates are generally poor across the region, but heating of this very moist airmass will still result in strong to very strong buoyancy (i.e. MLCAPE around 3000 J/kg) by late afternoon. Strong to severe storms are possible along this outflow as it impinges on this moist and buoyant airmass. Current trends suggest the greatest severe potential will exist this afternoon across southern WI and northern IL, where slightly stronger mid-level flow, backed surface winds, and an east-west baroclinic zone exists. Recently issued MCD 1983 addresses the short-term severe potential for this area. ...Central High Plains into the northern/central Plains... Strong heating and ample low/mid level moisture will promote the development of scattered thunderstorms by mid-afternoon over the foothills and plains of central/eastern CO. Additional isolated storms are possible farther north across western NE into the Black Hills region. Much of this area is within a corridor of modest mid-level flow on the northern periphery of the upper ridging covering the southern CONUS. Resulting modest shear may be enough for hail production with the initial development before these high-based storms trend towards outflow-dominant structures with time. These storms may persist into the evening, with an attendant threat for strong to severe gusts progressing into central NE before weakening. ...MO/AR... Clear skies and strong diurnal heating are expected across central/southern MO and much of AR. Temperatures in the upper 90s are expected, with dewpoints remaining in the mid 60s despite strong mixing. These hot and humid conditions will result in strong buoyancy this afternoon, with most guidance suggesting MLCAPE around 2000 J/kg. Shear will be weak, yielding mostly disorganized multicells, but the strongest storms will be capable of locally damaging wind gusts. ..Mosier/Wendt.. 08/18/2025 Read more