Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...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 1142 AM CDT Mon Jun 23 2025 Valid 231700Z - 241200Z Only minor changes to broad Elevated highlights across the greater Four Corners region and southern Great Basin were needed. Previous forecast (see below) remains on track. ..Williams.. 06/23/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Jun 23 2025/ ...Synopsis... Elevated fire weather concerns will persist across the greater southern Great Basin and Four Corners region today as breezy conditions continue within a dry air mass. Low to mid-level flow over the Intermountain West is expect to weaken over the next 24 hours as a leading shortwave impulse ejects northward into the Canadian Prairies. A secondary, weaker shortwave will settle into the lower CO Valley through today, which will maintain southwesterly flow across the southern Great Basin and into the Four Corners region. Diurnal heating of a very dry air mass (as sampled by regional 00z RAOBs) will promote wind gusts between 20-35 mph by late afternoon, though ensemble guidance continues to suggest that sustained winds will most likely remain between 15-20 mph for most locations. Regardless, increasing rainfall deficits and antecedent dry fuels/ongoing fires will support another day of at least low-end fire weather concerns as dry/breezy conditions become more prevalent through the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Mon Jun 23 16:45:02 UTC 2025.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Mon Jun 23 2025 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH LATE EVENING FROM THE CENTRAL PLAINS TO THE UPPER GREAT LAKES... ...SUMMARY... Storms with occasional damaging outflow gusts and marginally severe hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Upper Great Lakes to the Plains this afternoon/evening... A surface cold front will make slow southeastward progress from WI to IA and KS, in the wake of a primary shortwave trough moving over western ON. Surface heating is ongoing ahead of the front, where boundary-layer dewpoints range from the upper 60s to lower 70s beneath midlevel lapse rates of 7-8 C/km, which will drive MLCAPE of 2000-3000 J/kg. Convective inhibition will likewise weaken by early-mid afternoon, when thunderstorm development is likely along the front and differential heating zone in the SLGT risk corridor. Deep-layer flow will be a little stronger toward WI in closer proximity to the main belt of westerlies, where a mix clusters/line segments and transient supercell structures will be possible. The primary severe threat will be damaging outflow winds (60-70 mph) from roughly 20z-03z, though isolated large hail of 1-1.5 inches in diameter may also occur with the strongest storms. More loosely organized storm clusters are expected this afternoon through this evening into the southern High Plains, where thermodynamic profiles will favor isolated severe downbursts. ...Northern Maine later this evening... Around the northern periphery of a closed midlevel high over the Appalachians, a series of embedded speed maxima will move over ON/QC through tonight. Boundary-layer dewpoints in the 60s beneath midlevel lapse rates near 7 C/km, in combination with daytime heating, will boost MLCAPE to 1500-2000 J/kg with minimal convective inhibition by late afternoon. Thunderstorm development is expected upstream across QC in association with an embedded speed max/surface wave, and this convection will approach northern ME by late evening/early tonight. Though buoyancy will slowly weaken with the loss of daytime heating, low-level hodograph curvature and deep-layer westerly shear should be sufficient for an organized storm cluster to reach ME before weakening overnight. Isolated damaging winds will be the main threat with these storms. ..Thompson/Squitieri.. 06/23/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0721 AM CDT Mon Jun 23 2025 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE UPPER MS VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Storms with isolated severe wind gusts and hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Central Plains into the Upper MS Valley and Upper Great Lakes... Early-morning satellite imagery shows a shortwave trough progressing through ND and southern SK/MB. Surface analysis places the low associated with this shortwave over far northwestern ON, with an attendant cold front arcing from this low through the MN arrowhead and back through south-central MN, northwest IA, eastern/south-central NE to another low in northwest KS. Showers and thunderstorms are ongoing along this frontal zone from northeast NE into southern MN. Expectation is for the shortwave trough to continue northeastward through far northwest ON throughout the day, with the primary surface low also tracking northeastward just ahead of its parent shortwave. Gradual eastward/southeastward progress of the cold front is anticipated, although its forward progression will slow with time, particularly from the Mid MO Valley southwestward into the southern High Plains. A warm and moist airmass exists ahead of this front, with temperatures expected to reach the mid 80s to low 90s amid dewpoints in the upper 60s to low 70s. These conditions will result in strong buoyancy and little to no convective inhibition along much of the front by 21Z. Large-scale forcing for ascent will be negligible, but persist low-level convergence should be enough to initiate deep convection, with numerous to widespread thunderstorms anticipated. The stronger deep-layer vertical shear will lag behind the front across much of the region, but steep low-level lapse rates and ample moisture should still result in sporadic damaging gusts. There will be better overlap between the shear and buoyancy from WI into MI, and there is some chance for one or more forward-propagating line segments in this area. Some isolated hail is possible within the more robust early-stage storms. Storm mergers could also result in updrafts briefly becoming strong enough to produce hail. ...Southern and Central High Plains... Numerous thunderstorms are expected to develop during the afternoon amid persistent low-level convergence within the warm, moist, and weakly sheared airmass over the region. The lack of stronger shear will result in largely outflow-dominant storm structures. Given the high cloud bases and steep low-level lapse rates, damaging gusts are possible with the stronger storms. ...Northern ME... A convectively augmented vorticity maximum currently over northeastern ON is forecast progress eastward through southern QC and into the Canadian Maritimes during the period. Showers and thunderstorms will accompany this vorticity max, with a few stronger storms potentially glancing northern ME this evening. Moderately low to mid-level westerly flow will support the threat for some damaging gusts as these storms move through the region. ...Southeast... Scattered to numerous diurnally driven thunderstorm are expected across the region today. Shear will be weak, with a multicellular pulse mode anticipated. Given the ample moisture and likelihood of storm interactions, a few strong, water-loaded downbursts are possible. Limited coverage precludes the need for any severe probabilities. ..Mosier/Leitman.. 06/23/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0721 AM CDT Mon Jun 23 2025 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE UPPER MS VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Storms with isolated severe wind gusts and hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Central Plains into the Upper MS Valley and Upper Great Lakes... Early-morning satellite imagery shows a shortwave trough progressing through ND and southern SK/MB. Surface analysis places the low associated with this shortwave over far northwestern ON, with an attendant cold front arcing from this low through the MN arrowhead and back through south-central MN, northwest IA, eastern/south-central NE to another low in northwest KS. Showers and thunderstorms are ongoing along this frontal zone from northeast NE into southern MN. Expectation is for the shortwave trough to continue northeastward through far northwest ON throughout the day, with the primary surface low also tracking northeastward just ahead of its parent shortwave. Gradual eastward/southeastward progress of the cold front is anticipated, although its forward progression will slow with time, particularly from the Mid MO Valley southwestward into the southern High Plains. A warm and moist airmass exists ahead of this front, with temperatures expected to reach the mid 80s to low 90s amid dewpoints in the upper 60s to low 70s. These conditions will result in strong buoyancy and little to no convective inhibition along much of the front by 21Z. Large-scale forcing for ascent will be negligible, but persist low-level convergence should be enough to initiate deep convection, with numerous to widespread thunderstorms anticipated. The stronger deep-layer vertical shear will lag behind the front across much of the region, but steep low-level lapse rates and ample moisture should still result in sporadic damaging gusts. There will be better overlap between the shear and buoyancy from WI into MI, and there is some chance for one or more forward-propagating line segments in this area. Some isolated hail is possible within the more robust early-stage storms. Storm mergers could also result in updrafts briefly becoming strong enough to produce hail. ...Southern and Central High Plains... Numerous thunderstorms are expected to develop during the afternoon amid persistent low-level convergence within the warm, moist, and weakly sheared airmass over the region. The lack of stronger shear will result in largely outflow-dominant storm structures. Given the high cloud bases and steep low-level lapse rates, damaging gusts are possible with the stronger storms. ...Northern ME... A convectively augmented vorticity maximum currently over northeastern ON is forecast progress eastward through southern QC and into the Canadian Maritimes during the period. Showers and thunderstorms will accompany this vorticity max, with a few stronger storms potentially glancing northern ME this evening. Moderately low to mid-level westerly flow will support the threat for some damaging gusts as these storms move through the region. ...Southeast... Scattered to numerous diurnally driven thunderstorm are expected across the region today. Shear will be weak, with a multicellular pulse mode anticipated. Given the ample moisture and likelihood of storm interactions, a few strong, water-loaded downbursts are possible. Limited coverage precludes the need for any severe probabilities. ..Mosier/Leitman.. 06/23/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0721 AM CDT Mon Jun 23 2025 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE UPPER MS VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Storms with isolated severe wind gusts and hail will be possible today from the southern and central Plains northeastward into the Great Lakes. ...Central Plains into the Upper MS Valley and Upper Great Lakes... Early-morning satellite imagery shows a shortwave trough progressing through ND and southern SK/MB. Surface analysis places the low associated with this shortwave over far northwestern ON, with an attendant cold front arcing from this low through the MN arrowhead and back through south-central MN, northwest IA, eastern/south-central NE to another low in northwest KS. Showers and thunderstorms are ongoing along this frontal zone from northeast NE into southern MN. Expectation is for the shortwave trough to continue northeastward through far northwest ON throughout the day, with the primary surface low also tracking northeastward just ahead of its parent shortwave. Gradual eastward/southeastward progress of the cold front is anticipated, although its forward progression will slow with time, particularly from the Mid MO Valley southwestward into the southern High Plains. A warm and moist airmass exists ahead of this front, with temperatures expected to reach the mid 80s to low 90s amid dewpoints in the upper 60s to low 70s. These conditions will result in strong buoyancy and little to no convective inhibition along much of the front by 21Z. Large-scale forcing for ascent will be negligible, but persist low-level convergence should be enough to initiate deep convection, with numerous to widespread thunderstorms anticipated. The stronger deep-layer vertical shear will lag behind the front across much of the region, but steep low-level lapse rates and ample moisture should still result in sporadic damaging gusts. There will be better overlap between the shear and buoyancy from WI into MI, and there is some chance for one or more forward-propagating line segments in this area. Some isolated hail is possible within the more robust early-stage storms. Storm mergers could also result in updrafts briefly becoming strong enough to produce hail. ...Southern and Central High Plains... Numerous thunderstorms are expected to develop during the afternoon amid persistent low-level convergence within the warm, moist, and weakly sheared airmass over the region. The lack of stronger shear will result in largely outflow-dominant storm structures. Given the high cloud bases and steep low-level lapse rates, damaging gusts are possible with the stronger storms. ...Northern ME... A convectively augmented vorticity maximum currently over northeastern ON is forecast progress eastward through southern QC and into the Canadian Maritimes during the period. Showers and thunderstorms will accompany this vorticity max, with a few stronger storms potentially glancing northern ME this evening. Moderately low to mid-level westerly flow will support the threat for some damaging gusts as these storms move through the region. ...Southeast... Scattered to numerous diurnally driven thunderstorm are expected across the region today. Shear will be weak, with a multicellular pulse mode anticipated. Given the ample moisture and likelihood of storm interactions, a few strong, water-loaded downbursts are possible. Limited coverage precludes the need for any severe probabilities. ..Mosier/Leitman.. 06/23/2025 Read more