Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Thu Jun 26 2025 Valid 271200Z - 281200Z Elevated to locally critical fire weather conditions are expected across central and southwest Wyoming Friday. A broad increase in westerly winds at mid-levels in combination with a dry boundary layer will support an overlap of 15-20 mph surface winds and relative humidity of 10-15 percent Friday afternoon. Fuels remain drier west of the Continental Divide owing to rainfall deficits but heightened west-southwest winds should be enough to pose at least a broad elevated fire weather threat across central Wyoming. Otherwise, forecast (see below) remains on track with no significant changes to Elevated highlights. ..Williams.. 06/26/2025 .PREV DISCUSSION... /ISSUED 1249 AM CDT Thu Jun 26 2025/ ...Synopsis... Elevated fire weather conditions are expected across parts of central to southwest Wyoming Friday afternoon. Strengthening zonal flow over the northern Rockies will promote a more pronounced surface mass response across the northern High Plains on Friday compared to today/Thursday. Consequently, low-level winds will likely be slightly stronger across a broad swath of the eastern Great Basin and parts of the Four Corners region. In general, most locations from eastern NV into northern AZ, UT, southern ID, and WY will see breezy conditions with wind speeds generally in the mid teens. Across southwest to central WY, downslope flow into the WY Basin and in the lee of the Wind River Range will regionally augment surface winds to near 20 mph. Deep mixing will promote frequent gusts up to 25-30 mph by peak heating as RH values fall into the teens. Several hours of elevated conditions appear likely, and periods of critical conditions are possible. Fuels across much of WY are not as dry compared to locations southwest, but several hours of dry/windy conditions should promote adequate drying of dead finer fuels to support the fire weather concern. An expansion of the Elevated risk area appears possible if confidence in sustained/widespread 15+ mph winds increases across portions of the Great Basin/Four Corners region where fuels remain very dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Thu Jun 26 2025 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON INTO SATURDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...MUCH OF SOUTHERN AND CENTRAL MINNESOTA...ADJACENT NORTHWESTERN WISCONSIN... ...SUMMARY... Scattered strong thunderstorms, posing a risk for severe hail and wind, are possible across parts of the middle Missouri Valley into Upper Midwest Saturday afternoon into Saturday night. ...Discussion... Little change in the large-scale mid/upper flow is forecast from Friday into Saturday, with modest westerlies remaining generally zonal and confined to the northern tier of the U.S. and adjacent portions of southern Canada. Within this regime, one notable short wave trough is forecast to progress east of the Great Lakes into New England Saturday through Saturday night, as broad upstream troughing (with at least a couple of embedded smaller-scale perturbations) progresses eastward along the north central Canadian/U.S. border vicinity. In lower-levels, cooler and drier boundary-layer air is likely to be maintained across parts of northern New England, with another influx of cooler air spreading southeast of the Great Lakes through the upper Ohio Valley, northern Mid Atlantic coast and southern New England by late Saturday night. A trailing cold front is likely to continue slowly advancing east/southeast of the northern Rockies, through the northern Great Plains. Elsewhere, east of the high plains, seasonably moist boundary air may become characterized by moderate to strong potential instability with daytime heating. ...Northern Great Plains... The extent of convective development and its evolution remain unclear for this period due to a number of lingering uncertainties. Focus for renewed thunderstorm development could be impacted by outflow from convection developing Friday night into early Saturday. Additionally, strongest potential instability by Saturday afternoon is likely to become focused beneath the nose of the warmer and more strongly capping elevated mixed-layer air, roughly across the northern/eastern South Dakota vicinity, before slowly becoming suppressed southeastward. However, this might tend to become displaced to the south of the stronger and more favorably sheared westerlies. Even so, given thermodynamic profiles becoming characterized by steep lower/mid-tropospheric lapse rates and large CAPE, scattered strong to severe thunderstorm development appears possible ahead of the southeastward advancing cold front by late afternoon. Aided by forcing for ascent supported by low-level warm advection beneath broadly difluent upper flow, activity may consolidate into one or two eastward/southeastward propagating clusters by Saturday evening. ...Northern Mid Atlantic into Champlain Valley... A corridor of moderate to large developing mixed-layer CAPE, ahead of the southeastward advancing cold front, and within preceding deepening surface troughing, seems likely to provide the focus for vigorous thunderstorm development by late Saturday afternoon. Although lapse rates may be modest, and stronger potential instability across the northern Mid Atlantic may be displaced to the south of the better flow/shear across Upstate New York into New England, the environment may still become conducive to scattered strong thunderstorms accompanied by a risk for potentially damaging wind gusts. If/when lingering uncertainties become more clear, it is possible that severe probabilities could still be increased a bit further in later outlooks for this period. ..Kerr.. 06/26/2025 Read more