Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0452 PM CDT Tue Jul 15 2025 Valid 171200Z - 231200Z ...Day 3-4/Thursday-Friday... An upper-level low will usher in deeper monsoon moisture into the Desert Southwest and Greater Four Corners region through the end of the week aiding in promoting heavier rainfall with primarily diurnally driven thunderstorms over higher terrain. Dry thunderstorm threat will remain on the fringes of the deeper monsoon moisture across the eastern Great Basin, northern UT and Western Slope on Day 3/Thursday, moving even further north into the central ID/southwest MT mountains on Day 4/Friday. Increasing westerly flow associated with an approaching mid-level short wave will usher in stronger onshore winds into the Pacific Northwest on Day 4/Friday, increasing fire weather concerns east of the Cascades in WA/OR. ...Day 5-6/Saturday-Sunday... Breezy and dry conditions expand into the Northwestern U.S. as the mid-level trough moves into the region. 40 percent probabilities of critical fire weather conditions were added to the Columbia Basin and Snake River Plain where fuels are receptive to fire spread. The aforementioned trough and enhanced deep layer westerly flow will aid in the evacuation of monsoon moisture from the Western U.S., pushing thunderstorm development primarily along and east of the Continental Divide, south of the Mogollon Rim by Day 6/Sunday. ...Day 7-8/Monday-Tuesday... Uncertainty increases early next week regarding strength of troughing across the Pacific Northwest, precluding introduction of critical probabilities at this time. However, ensemble guidance does indicate a general troughing pattern holding on into early next week, which typically would bring dry, southwest flow and fire weather concerns to the Great Basin and portions of the Intermountain West. ..Williams.. 07/15/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0452 PM CDT Tue Jul 15 2025 Valid 171200Z - 231200Z ...Day 3-4/Thursday-Friday... An upper-level low will usher in deeper monsoon moisture into the Desert Southwest and Greater Four Corners region through the end of the week aiding in promoting heavier rainfall with primarily diurnally driven thunderstorms over higher terrain. Dry thunderstorm threat will remain on the fringes of the deeper monsoon moisture across the eastern Great Basin, northern UT and Western Slope on Day 3/Thursday, moving even further north into the central ID/southwest MT mountains on Day 4/Friday. Increasing westerly flow associated with an approaching mid-level short wave will usher in stronger onshore winds into the Pacific Northwest on Day 4/Friday, increasing fire weather concerns east of the Cascades in WA/OR. ...Day 5-6/Saturday-Sunday... Breezy and dry conditions expand into the Northwestern U.S. as the mid-level trough moves into the region. 40 percent probabilities of critical fire weather conditions were added to the Columbia Basin and Snake River Plain where fuels are receptive to fire spread. The aforementioned trough and enhanced deep layer westerly flow will aid in the evacuation of monsoon moisture from the Western U.S., pushing thunderstorm development primarily along and east of the Continental Divide, south of the Mogollon Rim by Day 6/Sunday. ...Day 7-8/Monday-Tuesday... Uncertainty increases early next week regarding strength of troughing across the Pacific Northwest, precluding introduction of critical probabilities at this time. However, ensemble guidance does indicate a general troughing pattern holding on into early next week, which typically would bring dry, southwest flow and fire weather concerns to the Great Basin and portions of the Intermountain West. ..Williams.. 07/15/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0452 PM CDT Tue Jul 15 2025 Valid 171200Z - 231200Z ...Day 3-4/Thursday-Friday... An upper-level low will usher in deeper monsoon moisture into the Desert Southwest and Greater Four Corners region through the end of the week aiding in promoting heavier rainfall with primarily diurnally driven thunderstorms over higher terrain. Dry thunderstorm threat will remain on the fringes of the deeper monsoon moisture across the eastern Great Basin, northern UT and Western Slope on Day 3/Thursday, moving even further north into the central ID/southwest MT mountains on Day 4/Friday. Increasing westerly flow associated with an approaching mid-level short wave will usher in stronger onshore winds into the Pacific Northwest on Day 4/Friday, increasing fire weather concerns east of the Cascades in WA/OR. ...Day 5-6/Saturday-Sunday... Breezy and dry conditions expand into the Northwestern U.S. as the mid-level trough moves into the region. 40 percent probabilities of critical fire weather conditions were added to the Columbia Basin and Snake River Plain where fuels are receptive to fire spread. The aforementioned trough and enhanced deep layer westerly flow will aid in the evacuation of monsoon moisture from the Western U.S., pushing thunderstorm development primarily along and east of the Continental Divide, south of the Mogollon Rim by Day 6/Sunday. ...Day 7-8/Monday-Tuesday... Uncertainty increases early next week regarding strength of troughing across the Pacific Northwest, precluding introduction of critical probabilities at this time. However, ensemble guidance does indicate a general troughing pattern holding on into early next week, which typically would bring dry, southwest flow and fire weather concerns to the Great Basin and portions of the Intermountain West. ..Williams.. 07/15/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0452 PM CDT Tue Jul 15 2025 Valid 171200Z - 231200Z ...Day 3-4/Thursday-Friday... An upper-level low will usher in deeper monsoon moisture into the Desert Southwest and Greater Four Corners region through the end of the week aiding in promoting heavier rainfall with primarily diurnally driven thunderstorms over higher terrain. Dry thunderstorm threat will remain on the fringes of the deeper monsoon moisture across the eastern Great Basin, northern UT and Western Slope on Day 3/Thursday, moving even further north into the central ID/southwest MT mountains on Day 4/Friday. Increasing westerly flow associated with an approaching mid-level short wave will usher in stronger onshore winds into the Pacific Northwest on Day 4/Friday, increasing fire weather concerns east of the Cascades in WA/OR. ...Day 5-6/Saturday-Sunday... Breezy and dry conditions expand into the Northwestern U.S. as the mid-level trough moves into the region. 40 percent probabilities of critical fire weather conditions were added to the Columbia Basin and Snake River Plain where fuels are receptive to fire spread. The aforementioned trough and enhanced deep layer westerly flow will aid in the evacuation of monsoon moisture from the Western U.S., pushing thunderstorm development primarily along and east of the Continental Divide, south of the Mogollon Rim by Day 6/Sunday. ...Day 7-8/Monday-Tuesday... Uncertainty increases early next week regarding strength of troughing across the Pacific Northwest, precluding introduction of critical probabilities at this time. However, ensemble guidance does indicate a general troughing pattern holding on into early next week, which typically would bring dry, southwest flow and fire weather concerns to the Great Basin and portions of the Intermountain West. ..Williams.. 07/15/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0513 Status Updates
STATUS REPORT ON WW 513 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..07/15/25 ATTN...WFO...MQT...DLH...MPX...GRB... STATUS REPORT FOR WS 513 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC013-053-061-071-103-131-152240- MI . MICHIGAN COUNTIES INCLUDED ARE BARAGA GOGEBIC HOUGHTON IRON MARQUETTE ONTONAGON MNC001-003-009-017-023-025-035-059-065-067-093-095-097-115-121- 141-145-151-153-171-152240- MN . MINNESOTA COUNTIES INCLUDED ARE AITKIN ANOKA BENTON CARLTON CHIPPEWA CHISAGO CROW WING ISANTI KANABEC KANDIYOHI MEEKER MILLE LACS MORRISON PINE POPE SHERBURNE STEARNS SWIFT TODD WRIGHT WIC003-005-007-013-031-051-095-099-107-113-125-129-152240- Read more

WW 0514 Status Updates
STATUS FOR WATCH 0514 HAS NOT BEEN ISSUED YET Read more

WW 0514 Status Updates
STATUS FOR WATCH 0514 HAS NOT BEEN ISSUED YET Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Tue Jul 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL NEBRASKA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE INTERIOR WEST...AND PARTS OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe gusts (some 75+ mph) and large hail are probable across parts of Nebraska late this afternoon and evening. Scattered severe gusts are also possible from the Upper Midwest to Utah and Wyoming this afternoon to mid-evening. ...20Z Update... The previous forecast remains on track, with only minor changes to the general thunder line to reflect the latest observations. Please refer to MCD 1675 for some of the latest short-term trends for storm development over portions of the central Plains. ..Squitieri.. 07/15/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Jul 15 2025/ ...Northern/Central Plains to the Upper Midwest... Primary focus for thunderstorms will be a slowly sagging, southward-moving cold front across the Upper Midwest and a couple mid-level perturbations moving east across the north-central states. Radar imagery shows a convectively augment disturbance moving east across northern SD and water-vapor imagery shows shortwave trough moving east across southeast WY. Both mid-level features will likely prove instrumental in storm coverage and the risk for severe activity later today. Despite stronger mid-level westerly flow relegated north of the 48th parallel, strong heating of a moist airmass will result in a very unstable boundary layer by mid afternoon from the Upper Midwest southwestward into the NE Sandhills. Storms will probably develop from eastern SD and into MN this afternoon near the front and ahead of the SD mid-level feature. Sufficient instability and effective bulk shear should be present along/ahead of the front to support organized convection, including some supercells. Large hail will be possible with the initially semi-discrete thunderstorms, before a rapid transition to a cluster/linear mode increases the threat for severe/damaging winds. This activity should quickly weaken by late evening as it encounters a less unstable airmass with eastward extent across the upper Great Lakes. A somewhat separate area of thunderstorms should initiate along/south of the front across parts of southern SD into NE by late afternoon/early evening. Greater instability will likely be present across this region compared to locations farther north, but deep-layer shear should be more modest (around 25-30 kt). Still, some large hail may occur initially given the presence of steep mid-level lapse rates. The threat for scattered to numerous severe/damaging winds is expected to increase through the evening across central NE as an intense bowing cluster develops and spreads southeastward. Isolated significant gusts of 75+ mph appear possible given the rather favorable thermodynamic environment. ...Great Basin into Wyoming... The only change for this portion of the region is to increase severe-wind probabilities across northern UT and surrounding states. The southern fringe of stronger mid-level westerlies was sampled by the 12 UTC Salt Lake City raob. With the approach of the upstream northern Rockies disturbance glancing the region later today, short-term model guidance (e.g., HREF members, time-lagged HRRR) is consistent in showing small clusters of storms moving east from northeast NV/northwest UT eastward into northern UT/southeast ID/far southwest WY. Inverted-V profiles will strongly favor evaporative cooling with the more rain-laden cores. Scattered severe gusts are possible with the more intense downbursts through early evening. Farther east, the closer proximity to the upper trough digging southeastward over the northern Rockies will promote scattered storms across northern into eastern WY this afternoon and evening. An organized cluster may evolve given 25-35 kt of deep-layer shear, while posing a threat for mainly severe/damaging winds given the presence of steepened low/mid-level lapse rates. Isolated large hail may also occur. ...Arizona... Modest mid-level east-northeasterlies will be present today across parts of AZ on the southern periphery of a mid-level anticyclone over the Southwest. Scattered thunderstorms should once again develop this afternoon over the higher terrain of southeast AZ and southwest NM. With very steep low/mid-level lapse rates expected with ample daytime heating, this activity may pose an isolated threat for severe winds as it spreads into the lower elevations of southern AZ through the evening. Read more