Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1149 AM CDT Fri Aug 15 2025 Valid 151700Z - 161200Z ...Dry Thunderstorms... Thermodynamic profiles continue to be supportive of dry thunderstorm development over portions of Northeast NV into southern ID/western WY and southward along the central UT mountain chain. Enhanced southwesterly flow associated with a trough over the Great Basin will support faster storm motions, particularly from a corridor from northeastern Nevada into southeastern ID, further limiting rainfall potential. A clearly evident, deeper moisture plume depicted by satellite imagery currently translating northward from northern AZ into eastern UT, should promote more wetting rain cores out of expected higher terrain shower/thunderstorm development this afternoon. PWATs across the Colorado Plateau and Western Slope should remain at or above 0.80" limiting lightning ignition efficiency in this region. Orographically forced convection and a few thunderstorms with limited rainfall across the Central Sierra Nevada mountains are also expected over increasingly dry fuels. ...Southern Nevada, southeastern Idaho and far southwest Montana... The mid-level trough will also support a swath of enhanced south to southwest winds (15-20 mph) across southern and eastern NV as well as portions of central ID mountains and Upper Snake River Plain. The winds combined with a dry boundary layer and surface relative humidity of 15% or below will promote elevated fire weather conditions amid dry fuels. ..Williams.. 08/15/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 15 2025/ ...Synopsis... Broad mid-level ridging over the Central US is forecast to build today, as weak westerly flow passes over it. Weak troughing over the Great Basin will gradually shift eastward bolstering mid-level flow over the region. A weak lee low over the High Plains will support west/southwesterly winds over much of the Great Basin and Intermountain West through this afternoon. 15-20 mph gusts will overlap with very warm and dry conditions (RH below 15) from eastern NV into portions of UT, WY and ID. Several hours of elevated fire weather conditions are probable given very dry and receptive fuels. ...Dry Thunder... Weak height falls from the upper trough over the West will continue to overspread robust monsoon moisture supporting isolated thunderstorms this afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture will overlap with dry boundary layer conditions and high cloud bases. This will favor dry storms with limited potential for wetting rainfall. The favorable thermodynamic conditions, coupled with 15-25 knot storm motions over top receptive fuels will continue to support dry lightning potential with these storms over the eastern Great Basin and central Rockies. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1149 AM CDT Fri Aug 15 2025 Valid 151700Z - 161200Z ...Dry Thunderstorms... Thermodynamic profiles continue to be supportive of dry thunderstorm development over portions of Northeast NV into southern ID/western WY and southward along the central UT mountain chain. Enhanced southwesterly flow associated with a trough over the Great Basin will support faster storm motions, particularly from a corridor from northeastern Nevada into southeastern ID, further limiting rainfall potential. A clearly evident, deeper moisture plume depicted by satellite imagery currently translating northward from northern AZ into eastern UT, should promote more wetting rain cores out of expected higher terrain shower/thunderstorm development this afternoon. PWATs across the Colorado Plateau and Western Slope should remain at or above 0.80" limiting lightning ignition efficiency in this region. Orographically forced convection and a few thunderstorms with limited rainfall across the Central Sierra Nevada mountains are also expected over increasingly dry fuels. ...Southern Nevada, southeastern Idaho and far southwest Montana... The mid-level trough will also support a swath of enhanced south to southwest winds (15-20 mph) across southern and eastern NV as well as portions of central ID mountains and Upper Snake River Plain. The winds combined with a dry boundary layer and surface relative humidity of 15% or below will promote elevated fire weather conditions amid dry fuels. ..Williams.. 08/15/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 15 2025/ ...Synopsis... Broad mid-level ridging over the Central US is forecast to build today, as weak westerly flow passes over it. Weak troughing over the Great Basin will gradually shift eastward bolstering mid-level flow over the region. A weak lee low over the High Plains will support west/southwesterly winds over much of the Great Basin and Intermountain West through this afternoon. 15-20 mph gusts will overlap with very warm and dry conditions (RH below 15) from eastern NV into portions of UT, WY and ID. Several hours of elevated fire weather conditions are probable given very dry and receptive fuels. ...Dry Thunder... Weak height falls from the upper trough over the West will continue to overspread robust monsoon moisture supporting isolated thunderstorms this afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture will overlap with dry boundary layer conditions and high cloud bases. This will favor dry storms with limited potential for wetting rainfall. The favorable thermodynamic conditions, coupled with 15-25 knot storm motions over top receptive fuels will continue to support dry lightning potential with these storms over the eastern Great Basin and central Rockies. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 15 2025 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Recent satellite imagery shows a pair of convectively generated vorticity maxima moving across the northern/central Plains, with the northernmost vorticity max over the eastern ND/SD border and the southernmost vorticity max over north-central NE. Showers and thunderstorms have persisted near these features over the last several hours, but the strongest cells in both of these clusters have recently shown a weakening trend. A moist and buoyant airmass, characterized by dewpoints in the upper 60s/low 70s, exists downstream and redevelopment is possible ahead of both of these vorticity maxima. How that redevelopment evolves is uncertain, with recent guidance offering varied solutions regarding overall coverage and evolution. Redevelopment appears most probable with the southern vorticity maxima, given the ample moist and buoyancy that exists downstream. This development should grow upscale quickly, with the resulting convective cluster then tracking southeastward. Recent guidance continues to trend farther south, so the wind probabilities were extended southward to cover this potential. Damaging gusts appear like the most likely threat through the evening. Current progression of the northern vorticity maximum takes it into a less buoyant airmass across central MN and northern WI, and redevelopment along/ahead of this disturbance appears less likely. Depending on the strength of the IA cluster, additional development is possible in its wake amid a strengthening low-level jet and associated warm-air advection over its outflow. Steep mid-level lapse rates should still be in place, supporting strong updrafts and large hail with these elevated storms. Lastly, a decaying convective line may reach the southwestern MN/northwestern IA vicinity late in the period. Given the potential for preceding storms, the amount of buoyancy that will still be in place remains is uncertain. However, if thunderstorm coverage is low or most storms develop farther east, enough buoyancy could remain to support strong updrafts capable of damaging gusts and/or hail within the convective line or any preceding more cellular storms. ..NE/SD this afternoon through tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. Isolated hail and strong gusts are possible with this initial activity. This activity will then track east-northeastward through the early evening into a progressively more moist and unstable air mass across NE and SD. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification and upscale growth through the evening across northern NE and central SD. Guidance continues to vary significantly with the strength of this MCS, but general consensus would suggest the threat for strong to severe gusts will persist across SD tonight. There is at least a low probability for the development of a well-organized MCS that could produce significant severe gusts. However, that probability is currently too low to introduce an unconditional sig wind area. ...TX Coastal Plain into the Hill Country and Southeast TX... A maturing tropical disturbance is near south TX, with associated outflow currently spreading northward across the TX Coastal Plain. Limited lightning has been noted with in the short-lived cores that have been developing along this outflow. This process of brief intensification along this outflow is expected throughout the day, with an overall increase in thunderstorm coverage anticipated. A modest increase in low to mid-level flow is expected along the eastern periphery of this system, spreading northward into central and southeast TX. Even so, shear will remain weak, with a disorganized multicellular pulse storm mode anticipated. Given the very moist profiles (i.e. PW values over 2"), a few water-loaded downbursts are possible, but should be isolated enough to preclude the need for severe probabilities. ..Mosier/Wendt.. 08/15/2025 Read more

MD 1950 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTHEAST NE INTO EXTREME NORTHWEST IA
Mesoscale Discussion 1950 NWS Storm Prediction Center Norman OK 0752 AM CDT Fri Aug 15 2025 Areas affected...Parts of northeast NE into extreme northwest IA Concerning...Severe potential...Watch unlikely Valid 151252Z - 151415Z Probability of Watch Issuance...20 percent SUMMARY...A threat for isolated hail and damaging gusts may continue into mid morning. DISCUSSION...A strong cell has recently evolved out of a storm cluster across northeast NE. This storm appears to be associated with an MCV that emerged out of the central High Plains. Steep lapse rates were observed on regional 12Z soundings, and this cell could continue to pose a threat of hail and localized strong gusts in the short term as it moves east-northeastward within a favorably unstable environment (with MUCAPE in excess of 2500 J/kg). The longevity of this storm this morning remains uncertain, due to its evolution into a discrete cell, and a general tendency for veering and weakening of the low-level jet with time. Recent HRRR/RRFS guidance suggests that a more organized cluster may eventually evolve downstream into northern IA in association with this MCV, though such an evolution may not occur until late morning or early afternoon, with the aid of diurnal destabilization. ..Dean/Hart.. 08/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...LBF... LAT...LON 42079848 42579813 42669619 41989599 41769675 41759818 42079848 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 1949 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST SD INTO EXTREME SOUTHEAST ND/WEST-CENTRAL MN
Mesoscale Discussion 1949 NWS Storm Prediction Center Norman OK 0701 AM CDT Fri Aug 15 2025 Areas affected...Northeast SD into extreme southeast ND/west-central MN Concerning...Severe potential...Watch unlikely Valid 151201Z - 151330Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe gusts and hail are possible this morning. DISCUSSION...A small but relatively long-lived storm cluster has recently intensified in the vicinity of a surface boundary across northeast SD, as it has encountered increasingly favorable buoyancy (with MUCAPE in excess of 3000 J/kg). The longevity of this cluster is uncertain, due to its elevated nature and some increase in downstream MUCINH noted in recent mesoanalysis estimates. Midlevel flow of 25-35 kt will continue to provide somewhat favorable effective shear for this cluster as long as it persists. Strong to locally severe gusts have been reported with this cluster over the last 60-90 minutes, and a threat for isolated damaging wind may continue in the short term as this cluster approaches far west-central MN. Hail in excess of 1-inch in diameter has also been recently observed, and stronger embedded cells could continue to pose an isolated hail threat, given the presence of steep midlevel lapse rates and favorable buoyancy. ..Dean/Hart.. 08/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...FGF...ABR...BIS... LAT...LON 46079814 46299751 46509606 46509566 46259528 45579542 45169571 45169665 45359783 46079814 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Fri Aug 15 2025 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Latest water vapor loop shows a convectively-aided shortwave trough moving across SD/NE. A cluster of intense thunderstorms has tracked across central/eastern SD overnight producing occasional wind damage (reference MCD #1949). Another small cluster of storms is over northeast NE. Both of these areas of convection are moving into a moist and potentially moderately unstable air mass, although they may take a few hours of heating to intensify further. Despite short-term uncertainty, a consensus of overnight CAM guidance depicts storms intensifying by early afternoon and tracking eastward across parts of MN, northeast IA, and western WI. Locally damaging wind gusts and hail will be possible. Have expanded the SLGT risk area slightly farther south in line with recent model solutions. ...SD/NE this afternoon/tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. This activity will track east-northeastward through the early evening into a progressively more moist and unstable air mass. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification through the evening across northern NE and central SD. Damaging winds and hail will be possible. Recent HRRR/RRFS runs suggest an upscale-organizing MCS could occur after midnight, tracking into western MN. Have extended the SLGT westward to account for this scenario. ..Hart/Dean.. 08/15/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Fri Aug 15 2025 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Latest water vapor loop shows a convectively-aided shortwave trough moving across SD/NE. A cluster of intense thunderstorms has tracked across central/eastern SD overnight producing occasional wind damage (reference MCD #1949). Another small cluster of storms is over northeast NE. Both of these areas of convection are moving into a moist and potentially moderately unstable air mass, although they may take a few hours of heating to intensify further. Despite short-term uncertainty, a consensus of overnight CAM guidance depicts storms intensifying by early afternoon and tracking eastward across parts of MN, northeast IA, and western WI. Locally damaging wind gusts and hail will be possible. Have expanded the SLGT risk area slightly farther south in line with recent model solutions. ...SD/NE this afternoon/tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. This activity will track east-northeastward through the early evening into a progressively more moist and unstable air mass. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification through the evening across northern NE and central SD. Damaging winds and hail will be possible. Recent HRRR/RRFS runs suggest an upscale-organizing MCS could occur after midnight, tracking into western MN. Have extended the SLGT westward to account for this scenario. ..Hart/Dean.. 08/15/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Fri Aug 15 2025 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Latest water vapor loop shows a convectively-aided shortwave trough moving across SD/NE. A cluster of intense thunderstorms has tracked across central/eastern SD overnight producing occasional wind damage (reference MCD #1949). Another small cluster of storms is over northeast NE. Both of these areas of convection are moving into a moist and potentially moderately unstable air mass, although they may take a few hours of heating to intensify further. Despite short-term uncertainty, a consensus of overnight CAM guidance depicts storms intensifying by early afternoon and tracking eastward across parts of MN, northeast IA, and western WI. Locally damaging wind gusts and hail will be possible. Have expanded the SLGT risk area slightly farther south in line with recent model solutions. ...SD/NE this afternoon/tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. This activity will track east-northeastward through the early evening into a progressively more moist and unstable air mass. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification through the evening across northern NE and central SD. Damaging winds and hail will be possible. Recent HRRR/RRFS runs suggest an upscale-organizing MCS could occur after midnight, tracking into western MN. Have extended the SLGT westward to account for this scenario. ..Hart/Dean.. 08/15/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Fri Aug 15 2025 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT FROM PARTS OF SOUTH DAKOTA INTO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe storms are likely today and tonight over parts of the northern Plains and Upper Mississippi Valley. ...MN/IA/WI... Latest water vapor loop shows a convectively-aided shortwave trough moving across SD/NE. A cluster of intense thunderstorms has tracked across central/eastern SD overnight producing occasional wind damage (reference MCD #1949). Another small cluster of storms is over northeast NE. Both of these areas of convection are moving into a moist and potentially moderately unstable air mass, although they may take a few hours of heating to intensify further. Despite short-term uncertainty, a consensus of overnight CAM guidance depicts storms intensifying by early afternoon and tracking eastward across parts of MN, northeast IA, and western WI. Locally damaging wind gusts and hail will be possible. Have expanded the SLGT risk area slightly farther south in line with recent model solutions. ...SD/NE this afternoon/tonight... Strong heating and ample mid-level moisture will result in scattered high-based thunderstorm development across eastern WY and western NE/SD by late afternoon. This activity will track east-northeastward through the early evening into a progressively more moist and unstable air mass. The combination of improving thermodynamic environment and an intensifying nocturnal low-level jet will likely aid in thunderstorm intensification through the evening across northern NE and central SD. Damaging winds and hail will be possible. Recent HRRR/RRFS runs suggest an upscale-organizing MCS could occur after midnight, tracking into western MN. Have extended the SLGT westward to account for this scenario. ..Hart/Dean.. 08/15/2025 Read more