Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 18 2025 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Strong to severe storms capable of damaging winds are possible in parts of the Upper Midwest today. Isolated to widely scattered storms with large hail and severe winds are possible in parts of the central/northern Plains through tonight. ...Central High Plains... A broad upper trough over the northern Plains will move east today with an attendant surface low and cold front also moving east. Behind the departing surface low, weak upslope flow is expected across portions of western SD, northeastern WY. Strong heating and steep mid-level lapse rates should allow for diurnal destabilization with widely scattered thunderstorms expected along a lee trough by the afternoon. Elongated hodographs, courtesy of 30-40 kt of westerly flow aloft, will allow for some organized storms including supercells or clusters. Steep mid-level lapse rates, and moderate buoyancy will support a hail risk. Farther south, stronger heating and mixing will limit low-level moisture across southeastern WY and northeastern CO. Still, enough CAPE should be present for scattered high-based storms near peak heating. The steep low-level lapse rates and any clustering that develops should support damaging winds as storms spread eastward into northeast CO and western NE. Some potential exists for a longer-lived cluster to spread eastward into central/eastern NE and northern KS overnight. Should this occur, damaging winds and some hail would be the primary concerns, though this scenario remains highly uncertain given weaker forecast low-level jet. ...Midwest... One or more clusters of thunderstorms or an MCV is expected to be ongoing at the start of the period in the vicinity of the warm front across portions of IA/MN, casting significant uncertainty on the overall convective evolution for the day. Filtered diurnal heating and nebulous ascent from the broad trough over the northern Plains could support continuation of these storms and additional development into southern WI and northern IL this afternoon. While complications abound, substantial buoyancy (3000-4000 J/kg of MLCAPE) and dewpoints in the mid 70s F south of the composite front/remnant outflow will be supportive of occasional vigorous updrafts. Modest enhancement of the mid and upper-level flow could support a few semi-organized clusters or transient supercells with damaging wind potential. Given the potential for outflow or thunderstorm clusters to significantly alter the environment, confidence in higher wind probabilities is low. ...Southwest into central Montana... Despite a strong ridge building into the northern Rockies, sufficient moisture may promote thunderstorm development in the higher terrain this afternoon. 20-30 kt of flow aloft will be sufficient to support at least marginally organized storms. However, strong mixing during the afternoon could limit buoyancy and storm coverage. Occasional strong, gusty outflow winds are possible with any high-based storms, but confidence in severe potential remains low. ..Lyons/Kerr.. 08/18/2025 Read more

WW 0598 Status Updates
STATUS FOR WATCH 0598 HAS NOT BEEN ISSUED YET Read more

WW 0598 Status Updates
STATUS FOR WATCH 0598 HAS NOT BEEN ISSUED YET Read more

WW 0598 Status Updates
STATUS FOR WATCH 0598 HAS NOT BEEN ISSUED YET Read more

MD 1981 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHWEST NEBRASKA AND SOUTHERN SOUTH DAKOTA
Mesoscale Discussion 1981 NWS Storm Prediction Center Norman OK 0845 PM CDT Sun Aug 17 2025 Areas affected...northwest Nebraska and southern South Dakota Concerning...Severe potential...Watch possible Valid 180145Z - 180345Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorms capable of large hail and strong winds are ongoing across portions of the area. These storms should continue through the evening and perhaps increase in coverage/organization. Trends will continue to be watched for a potential severe thunderstorm watch. DISCUSSION...Several clusters of discrete storms -- with at least transient supercellular characteristics -- are ongoing across portions of the area. These storms are embedded within a belt of stronger upper-level winds stretching from Baja northeast into northern Minnesota, and may have initiated in association with a subtle vorticity maximum coming off the higher terrain of northern Colorado. These storms are on the western edge of the MUCAPE gradient, with higher MUCAPE -- 3000+ J/kg -- to the east. Effective-layer shear is variable between 30-40 knots which is likely contributing to the supercellular structures, and these storms will continue to pose a threat for damaging winds and large hail. The evolution of these multi-cell/supercell clusters this evening is unclear. Currently thinking is that given the environment in place, these storms' outflows/cold pools should congeal into one or more small MCS clusters, leading to an increased potential in severe wind. Trends across the region are being monitored for potential watch issuance. If convective trends suggest upscale growth is imminent a severe thunderstorm watch may become necessary. ..Marsh/Smith.. 08/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...ABR...GID...LBF...UNR...CYS... LAT...LON 41169723 41329857 41500023 41780132 42250254 43000348 43660276 43690098 43699938 43729851 43419716 42609657 41729654 41169723 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ...Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ...IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ...Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ...Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ..Lyons.. 08/18/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ...Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ...IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ...Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ...Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ..Lyons.. 08/18/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ...Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ...IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ...Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ...Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ..Lyons.. 08/18/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ...Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ...IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ...Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ...Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ..Lyons.. 08/18/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ...Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ...IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ...Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ...Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ..Lyons.. 08/18/2025 Read more

MD 1980 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN IOWA AND SOUTHWESTERN MINNESOTA
Mesoscale Discussion 1980 NWS Storm Prediction Center Norman OK 0643 PM CDT Sun Aug 17 2025 Areas affected...northern iowa and southwestern Minnesota Concerning...Severe potential...Watch possible Valid 172343Z - 180145Z Probability of Watch Issuance...40 percent SUMMARY...Occasionally intensifying supercell structures posing a risk for short-lived tornadoes and locally damaging wind gusts may continue into the 8-10 PM CDT time frame, before diminishing. It is not clear that a severe weather watch is needed, but trends will continue to be monitored for this possibility. DISCUSSION...A stalled surface frontal zone has become the focus for increasing thunderstorm development over the past hour or so, as lift associated with focused low-level convergence and weak warm advection have been sufficient to overcome any lingering late afternoon mid-level inhibition. Although lower/mid-tropospheric lapse rates are mostly modest, at best, seasonably high boundary-layer moisture content is contributing to sizable CAPE. Low-level buoyancy associated with surface dew points in the mid/upper 70s is potentially supportive of large near surface updraft accelerations, as weak to modest, clockwise curved low-level hodographs contribute to updraft rotation. Deep-layer shear appears marginal for sustained supercell structures, but isolated to widely scattered stronger storms may continue to pose a risk for generally short-lived tornadoes and localized damaging wind gusts into the 01-03Z time frame, before inhibition for boundary-layer parcels increases with the onset of boundary-layer cool. ..Kerr/Smith.. 08/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...MPX...DMX...FSD... LAT...LON 44279511 43719313 43139205 42809113 42189073 42209252 42719404 43679601 44279511 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

No watches are valid as of Sun Aug 17 23:45:02 UTC 2025.