Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Potential for organized severe weather is expected to remain low on Tuesday. ...Synopsis... The upper-level ridge will continue to amplify across the Rockies and into parts of the Plains on Tuesday. A low amplitude trough will persist in the lower Great Lakes and Northeast. At the surface, a cold front will continue southward through the central Plains into the southern Plains. Moderate to strong buoyancy will likely develop to the south and west of the surface boundary. However, mid-level flow and effective shear will be rather weak. In general, given weak overall forcing, isolated to widely scattered storms are expected. Some of these storms could be stronger and produce strong wind gusts. Predictability of where this will occur is too low to warrant severe probabilities. Modestly moist upslope flow into the Front Range could promote isolated storm development. Shear should be somewhat stronger in eastern Colorado. Confidence in storm coverage (given the intensifying ridge aloft) and storms being able to move off the terrain remains low, however. ..Wendt.. 08/17/2025 Read more

MD 1974 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN VERMONT...SOUTHERN AND CENTRAL NEW HAMPSHIRE...AND SOUTHERN MAINE
Mesoscale Discussion 1974 NWS Storm Prediction Center Norman OK 1241 PM CDT Sun Aug 17 2025 Areas affected...southern Vermont...southern and central New Hampshire...and southern Maine Concerning...Severe potential...Watch unlikely Valid 171741Z - 171945Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong to severe storms are possible this afternoon. DISCUSSION...A strong cold front is moving south across northern Vermont, New Hampshire and Maine with temperatures in the upper 50s in its wake. Strong heating is occurring ahead of this cold front with temperatures in the upper 80s and dewpoints in the 60s across southern New Hampshire and southern Maine. Taller cumulus have started to develop along the front as it crosses the White Mountains. Within the next 1 to 2 hours, expect storms to develop along the front as it moves into the hot airmass east of the terrain. Cooling temperatures aloft and strengthening mid-level flow will provide an environment favorable for a few strong to severe storms this afternoon before the front moves offshore. Overall, the limited instability and relatively confined threat area near the coast should limit the need for a severe thunderstorm watch. ..Bentley/Mosier.. 08/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BTV...ALY... LAT...LON 42897294 43227294 43587265 44147208 44507076 44756903 44406872 43926895 43447001 42977056 42887171 42897294 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WITHIN THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest on Monday. Isolated to widely scattered storms could produce large hail and severe winds in parts of the central/northern Plains. ...Northern/Central Plains... Isolated to widely scattered storms to develop either along a weak surface trough, within the terrain in eastern Wyoming/Black Hills, or a cold front near the Nebraska/South Dakota border. Strong buoyancy and effective shear of 30-40 kts will allow for the stronger storms to be organized. Large hail and severe winds would be the expected hazards. There is some potential for a more organized cluster of storms to progress eastward. This would most likely occur near the cold front during late afternoon/evening. However, a very weak low-level jet and uncertain cold pool organization keeps confidence too low for any increase in wind probabilities. ...Upper Midwest... Showers/thunderstorms are expected to be ongoing Monday morning. This will have an impact on where the greatest destabilization will occur during the afternoon. Furthermore, the region will be in the wake of a departing shortwave trough/MCV with mid-level ascent being nebulous and uncertain. Current guidance suggests the greatest potential for afternoon storms will exist in parts of central/southern Wisconsin into northern Illinois. There, some surface heating and low-level lift near a weak surface low/triple point could promote widely scattered to scattered thunderstorms. While the exact placement of this activity remains uncertain, the environment would support marginal supercells and multicell clusters with a primary hazard of damaging winds. Farther southwest into Iowa, strong buoyancy is expected to develop south of any outflow from morning activity. MLCAPE around 3000 J/kg would support a threat for isolated wind damage even with weaker effective shear than farther north. However, with little in the way of mid-level ascent and uncertain low-level forcing gives low confidence in storm coverage. ...Southwest into central Montana... Though a ridge will be building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain. Flow aloft will be strong enough to support at least marginally organized storms. However, it is not clear how intense storms will be given some signal for moisture to mix out during the afternoon. Strong, gusty outflow winds are possible, but confidence in severe potential remains low. ..Wendt.. 08/17/2025 Read more

MD 1973 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWEST PENNSYLVANIA
Mesoscale Discussion 1973 NWS Storm Prediction Center Norman OK 1139 AM CDT Sun Aug 17 2025 Areas affected...southwest Pennsylvania Concerning...Severe potential...Watch unlikely Valid 171639Z - 171745Z Probability of Watch Issuance...5 percent SUMMARY...A few strong storms are possible across southwest Pennsylvania through early afternoon. DISCUSSION...A few storms have developed across southwest Pennsylvania along a southward moving surface trough. Surface heating has resulted in some instability, but weak mid-level lapse rates on the 12Z PIT RAOB are limiting overall buoyancy. Nonetheless, a few stronger storms along this front could produce occasional damaging winds (evidenced by a recent 39 knot gust at KPIT). However, any severe wind threat should be very isolated given weak shear (19 knots on 12Z PIT RAOB) and the aforementioned thermodynamic concerns. A severe thunderstorm watch is not anticipated. ..Bentley/Mosier.. 08/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CTP...LWX...PBZ... LAT...LON 40718051 40807882 40547769 40017759 39727823 39697928 39698019 39868060 40138071 40718051 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1143 AM CDT Sun Aug 17 2025 Valid 171700Z - 181200Z ...Dry Thunder Northern Rockies/northern Great Basin... A mid-level trough and weak frontal boundary interacting with residual monsoon moisture, along with daytime instability will contribute to another round of thunderstorms mainly over the portions of central/southern ID and far northern NV. Higher atmospheric moisture content with PWAT values around 1.00 inch and surface dewpoints in the 50s could support wetter rain cores across central ID. However, faster northeast storm trajectories of up to 30 knots will limit residence time, likely leading to a mixed wet/dry thunderstorm environment this afternoon. Farther south where monsoon moisture decreases, isolated dry thunderstorm development and new lightning ignitions are possible along higher terrain south of the Snake River Plain into far northern Nevada, where fuels remain receptive. ...Eastern Great Basin... Dry and breezy conditions are still expected for much of eastern NV and west-central UT today aided by broad southwest flow southeast of the mid-level trough situated over the Northwestern U.S. Sustained southwest surface winds of 10-15 mph, localized 20 mph in southern NV/western UT, relative humidity of 10-15 percent range and dry fuels will support increased fire spread potential. ..Williams.. 08/17/2025 .PREV DISCUSSION... /ISSUED 0200 AM CDT Sun Aug 17 2025/ ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ...Please see www.spc.noaa.gov/fire for graphic product... Read more