Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Thu Jul 25 2024 Valid 251700Z - 261200Z A few minor changes to the Elevated highlights were made based on the latest guidance. The forecast is otherwise unchanged. ..Wendt.. 07/25/2024 .PREV DISCUSSION... /ISSUED 1248 AM CDT Thu Jul 25 2024/ ...Synopsis... Isolated dry thunderstorms are anticipated across portions of southern Idaho into southwestern Montana as an upper-level trough progresses eastward across the Northwest. Additionally, elevated fire-weather conditions are expected across the southern Cascades, portions of northern Montana, and the northern Great Plains. ...Pacific Northwest... As an upper-level trough is forecast to progress eastward out of the Pacific Northwest and into Montana, isolated dry thunderstorms are expected across southeastern Idaho and into southwestern Montana over receptive fuels. Some trimming of the previous forecast area, particularly over southwestern Idaho, was necessary after significant wetting rainfall occurred the previous day. Additionally, current forecast guidance suggests a mix of both wet and dry thunderstorms, precluding the introduction of a scattered dry thunder area despite widespread thunderstorm coverage. Forecast profiles across southwestern Montana show deep inverted-v boundary layers supportive of gusty thunderstorm outflow that could contribute to wildfire spread with both existing fires and new lightning ignitions. Elevated fire-weather conditions are expected to occur over the southern Cascades, especially where local gap flow enhanced winds could contribute to wildfire spread with existing fires. Some trimming of the previous forecast areas was necessary to account for wetting rainfall occurring the previous day, leaving fuels less receptive to ignition. Some elevated fire-weather conditions are also possible in portions of north-central Montana, but the overlap of stronger surface winds/low relative humidity and receptive fuels is somewhat narrow. ...Northern Great Plains... Elevated fire-weather conditions are anticipated, particularly along portions of western Montana and Wyoming, into eastern Nebraska and the Dakotas. Strong southerly flow, coupled with hot, dry boundary layer profiles, are expected to persist for much of the afternoon and into the evening. Fuels in this region will be at or exceed the 90th percentile for ERCs, but conditions are expected to remain below critical criteria for wind and relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Jul 25 2024 Valid 251300Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Strong to locally severe thunderstorms with wind gusts will be possible today across Montana and the northern Rockies/Great Basin, southern Arizona, and Carolinas/Mid-Atlantic States. ...Montana/Northern Rockies to Great Basin... A prominent upper-level trough will spread eastward from British Columbia toward Alberta/Saskatchewan, with strengthening cyclonic westerlies overspreading the northern Rockies/Montana. Scattered thunderstorm development is forecast to initiate off the higher terrain this afternoon, and in advance of a cold front, across central Montana, where a hot and deeply mixed boundary layer may become characterized by modest instability. Forecast soundings are suggestive of 40-60 F temperature-dew point spreads by peak heating. A downward mixing of 30-40+ kt ambient southwesterly to westerly flow in the 700-500 mb layer may contribute to severe-caliber wind gusts in consolidating outflows, as convection spreads eastward into this evening toward eastern Montana and possibly western North Dakota. Other high-based storms capable of severe-caliber wind gusts could occur as far southwest as parts of the Great Basin later this afternoon and evening, within an unstable air mass ahead of a front across the northern Intermountain region. ...Arizona... Lingering early day outflow/cloud cover via yesterday's relatively active convection should generally abate by afternoon. As the boundary layer diurnally warms and destabilizes, thunderstorms are again likely to initiate across the Mogollon Rim and adjacent mountains of southwest New Mexico this afternoon. Given the position and movement of the mid-level high, somewhat stronger (around 15 kt) northeasterly steering flow will remain focused across southeast into adjacent portions of central Arizona. Localized severe-caliber wind gusts and blowing dust will again be possible this afternoon through early/mid-evening as storms progress south-southwestward onto the desert floor. ...Carolinas/Mid-Atlantic States... Cloud cover will likely remain prevalent regionally today with showers/some thunderstorms ongoing this morning to the south of the primary front that will be shifting south-southeastward across the northern and central Appalachians. Near the southern periphery of the larger-scale mid-level troughing, a belt of 30-40 kt south-southwesterly flow in the 850-500 mb layer may enhance convective development within a plume of seasonably high moisture content. While lapse rates and overall buoyancy will be modest, heavy precipitation loading and downward mixing of momentum may contribute to a few strong downdrafts with the possibility of locally damaging surface gusts/tree damage this afternoon. ...Middle/Upper Texas Coast and Southern Louisiana... Extensive showers and some thunderstorms are ongoing along the Texas coast early today. Influenced by a weak mid-level disturbance, some guidance suggests that a strengthening of low-level winds/shear will occur today. However, mid-level winds will remain weak, while the aforementioned convection should considerably limit destabilization inland. These factors seem likely to minimize the potential for anything beyond a few very weak/transient mesocyclones. ..Guyer/Jewell.. 07/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Jul 25 2024 Valid 251300Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Strong to locally severe thunderstorms with wind gusts will be possible today across Montana and the northern Rockies/Great Basin, southern Arizona, and Carolinas/Mid-Atlantic States. ...Montana/Northern Rockies to Great Basin... A prominent upper-level trough will spread eastward from British Columbia toward Alberta/Saskatchewan, with strengthening cyclonic westerlies overspreading the northern Rockies/Montana. Scattered thunderstorm development is forecast to initiate off the higher terrain this afternoon, and in advance of a cold front, across central Montana, where a hot and deeply mixed boundary layer may become characterized by modest instability. Forecast soundings are suggestive of 40-60 F temperature-dew point spreads by peak heating. A downward mixing of 30-40+ kt ambient southwesterly to westerly flow in the 700-500 mb layer may contribute to severe-caliber wind gusts in consolidating outflows, as convection spreads eastward into this evening toward eastern Montana and possibly western North Dakota. Other high-based storms capable of severe-caliber wind gusts could occur as far southwest as parts of the Great Basin later this afternoon and evening, within an unstable air mass ahead of a front across the northern Intermountain region. ...Arizona... Lingering early day outflow/cloud cover via yesterday's relatively active convection should generally abate by afternoon. As the boundary layer diurnally warms and destabilizes, thunderstorms are again likely to initiate across the Mogollon Rim and adjacent mountains of southwest New Mexico this afternoon. Given the position and movement of the mid-level high, somewhat stronger (around 15 kt) northeasterly steering flow will remain focused across southeast into adjacent portions of central Arizona. Localized severe-caliber wind gusts and blowing dust will again be possible this afternoon through early/mid-evening as storms progress south-southwestward onto the desert floor. ...Carolinas/Mid-Atlantic States... Cloud cover will likely remain prevalent regionally today with showers/some thunderstorms ongoing this morning to the south of the primary front that will be shifting south-southeastward across the northern and central Appalachians. Near the southern periphery of the larger-scale mid-level troughing, a belt of 30-40 kt south-southwesterly flow in the 850-500 mb layer may enhance convective development within a plume of seasonably high moisture content. While lapse rates and overall buoyancy will be modest, heavy precipitation loading and downward mixing of momentum may contribute to a few strong downdrafts with the possibility of locally damaging surface gusts/tree damage this afternoon. ...Middle/Upper Texas Coast and Southern Louisiana... Extensive showers and some thunderstorms are ongoing along the Texas coast early today. Influenced by a weak mid-level disturbance, some guidance suggests that a strengthening of low-level winds/shear will occur today. However, mid-level winds will remain weak, while the aforementioned convection should considerably limit destabilization inland. These factors seem likely to minimize the potential for anything beyond a few very weak/transient mesocyclones. ..Guyer/Jewell.. 07/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Jul 25 2024 Valid 251300Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Strong to locally severe thunderstorms with wind gusts will be possible today across Montana and the northern Rockies/Great Basin, southern Arizona, and Carolinas/Mid-Atlantic States. ...Montana/Northern Rockies to Great Basin... A prominent upper-level trough will spread eastward from British Columbia toward Alberta/Saskatchewan, with strengthening cyclonic westerlies overspreading the northern Rockies/Montana. Scattered thunderstorm development is forecast to initiate off the higher terrain this afternoon, and in advance of a cold front, across central Montana, where a hot and deeply mixed boundary layer may become characterized by modest instability. Forecast soundings are suggestive of 40-60 F temperature-dew point spreads by peak heating. A downward mixing of 30-40+ kt ambient southwesterly to westerly flow in the 700-500 mb layer may contribute to severe-caliber wind gusts in consolidating outflows, as convection spreads eastward into this evening toward eastern Montana and possibly western North Dakota. Other high-based storms capable of severe-caliber wind gusts could occur as far southwest as parts of the Great Basin later this afternoon and evening, within an unstable air mass ahead of a front across the northern Intermountain region. ...Arizona... Lingering early day outflow/cloud cover via yesterday's relatively active convection should generally abate by afternoon. As the boundary layer diurnally warms and destabilizes, thunderstorms are again likely to initiate across the Mogollon Rim and adjacent mountains of southwest New Mexico this afternoon. Given the position and movement of the mid-level high, somewhat stronger (around 15 kt) northeasterly steering flow will remain focused across southeast into adjacent portions of central Arizona. Localized severe-caliber wind gusts and blowing dust will again be possible this afternoon through early/mid-evening as storms progress south-southwestward onto the desert floor. ...Carolinas/Mid-Atlantic States... Cloud cover will likely remain prevalent regionally today with showers/some thunderstorms ongoing this morning to the south of the primary front that will be shifting south-southeastward across the northern and central Appalachians. Near the southern periphery of the larger-scale mid-level troughing, a belt of 30-40 kt south-southwesterly flow in the 850-500 mb layer may enhance convective development within a plume of seasonably high moisture content. While lapse rates and overall buoyancy will be modest, heavy precipitation loading and downward mixing of momentum may contribute to a few strong downdrafts with the possibility of locally damaging surface gusts/tree damage this afternoon. ...Middle/Upper Texas Coast and Southern Louisiana... Extensive showers and some thunderstorms are ongoing along the Texas coast early today. Influenced by a weak mid-level disturbance, some guidance suggests that a strengthening of low-level winds/shear will occur today. However, mid-level winds will remain weak, while the aforementioned convection should considerably limit destabilization inland. These factors seem likely to minimize the potential for anything beyond a few very weak/transient mesocyclones. ..Guyer/Jewell.. 07/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Jul 25 2024 Valid 251300Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Strong to locally severe thunderstorms with wind gusts will be possible today across Montana and the northern Rockies/Great Basin, southern Arizona, and Carolinas/Mid-Atlantic States. ...Montana/Northern Rockies to Great Basin... A prominent upper-level trough will spread eastward from British Columbia toward Alberta/Saskatchewan, with strengthening cyclonic westerlies overspreading the northern Rockies/Montana. Scattered thunderstorm development is forecast to initiate off the higher terrain this afternoon, and in advance of a cold front, across central Montana, where a hot and deeply mixed boundary layer may become characterized by modest instability. Forecast soundings are suggestive of 40-60 F temperature-dew point spreads by peak heating. A downward mixing of 30-40+ kt ambient southwesterly to westerly flow in the 700-500 mb layer may contribute to severe-caliber wind gusts in consolidating outflows, as convection spreads eastward into this evening toward eastern Montana and possibly western North Dakota. Other high-based storms capable of severe-caliber wind gusts could occur as far southwest as parts of the Great Basin later this afternoon and evening, within an unstable air mass ahead of a front across the northern Intermountain region. ...Arizona... Lingering early day outflow/cloud cover via yesterday's relatively active convection should generally abate by afternoon. As the boundary layer diurnally warms and destabilizes, thunderstorms are again likely to initiate across the Mogollon Rim and adjacent mountains of southwest New Mexico this afternoon. Given the position and movement of the mid-level high, somewhat stronger (around 15 kt) northeasterly steering flow will remain focused across southeast into adjacent portions of central Arizona. Localized severe-caliber wind gusts and blowing dust will again be possible this afternoon through early/mid-evening as storms progress south-southwestward onto the desert floor. ...Carolinas/Mid-Atlantic States... Cloud cover will likely remain prevalent regionally today with showers/some thunderstorms ongoing this morning to the south of the primary front that will be shifting south-southeastward across the northern and central Appalachians. Near the southern periphery of the larger-scale mid-level troughing, a belt of 30-40 kt south-southwesterly flow in the 850-500 mb layer may enhance convective development within a plume of seasonably high moisture content. While lapse rates and overall buoyancy will be modest, heavy precipitation loading and downward mixing of momentum may contribute to a few strong downdrafts with the possibility of locally damaging surface gusts/tree damage this afternoon. ...Middle/Upper Texas Coast and Southern Louisiana... Extensive showers and some thunderstorms are ongoing along the Texas coast early today. Influenced by a weak mid-level disturbance, some guidance suggests that a strengthening of low-level winds/shear will occur today. However, mid-level winds will remain weak, while the aforementioned convection should considerably limit destabilization inland. These factors seem likely to minimize the potential for anything beyond a few very weak/transient mesocyclones. ..Guyer/Jewell.. 07/25/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Thu Jul 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... A weak upper trough will migrate across the Midwest early in the forecast period. However, weak deep-layer flow and relatively modest large-scale ascent may limit severe potential. Generally low-amplitude upper troughing will then prevail across the eastern third of the CONUS through much of the work week. Meanwhile, an expansive upper ridge centered over the Rockies/High Plains vicinity will persist for much of the Day 4-8 period. Some severe potential is possible in a northwesterly flow regime over the Mid-MO to Mid-MS Valley around Days 5-6/Mon-Tue, but this risk would largely be driven by mesoscale factors not well resolved at longer time periods. Late in the period, forecast guidance suggests a shortwave trough may develop eastward atop the upper ridge in the vicinity of the northern Plains. This break down of the upper ridge amid a very moist and unstable boundary layer would be a favorable pattern for potential MCS development around Day 7 or 8/Wed or Thu. Confidence in this scenario remains too low to include probabilities at this time, but may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Thu Jul 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... A weak upper trough will migrate across the Midwest early in the forecast period. However, weak deep-layer flow and relatively modest large-scale ascent may limit severe potential. Generally low-amplitude upper troughing will then prevail across the eastern third of the CONUS through much of the work week. Meanwhile, an expansive upper ridge centered over the Rockies/High Plains vicinity will persist for much of the Day 4-8 period. Some severe potential is possible in a northwesterly flow regime over the Mid-MO to Mid-MS Valley around Days 5-6/Mon-Tue, but this risk would largely be driven by mesoscale factors not well resolved at longer time periods. Late in the period, forecast guidance suggests a shortwave trough may develop eastward atop the upper ridge in the vicinity of the northern Plains. This break down of the upper ridge amid a very moist and unstable boundary layer would be a favorable pattern for potential MCS development around Day 7 or 8/Wed or Thu. Confidence in this scenario remains too low to include probabilities at this time, but may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Thu Jul 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... A weak upper trough will migrate across the Midwest early in the forecast period. However, weak deep-layer flow and relatively modest large-scale ascent may limit severe potential. Generally low-amplitude upper troughing will then prevail across the eastern third of the CONUS through much of the work week. Meanwhile, an expansive upper ridge centered over the Rockies/High Plains vicinity will persist for much of the Day 4-8 period. Some severe potential is possible in a northwesterly flow regime over the Mid-MO to Mid-MS Valley around Days 5-6/Mon-Tue, but this risk would largely be driven by mesoscale factors not well resolved at longer time periods. Late in the period, forecast guidance suggests a shortwave trough may develop eastward atop the upper ridge in the vicinity of the northern Plains. This break down of the upper ridge amid a very moist and unstable boundary layer would be a favorable pattern for potential MCS development around Day 7 or 8/Wed or Thu. Confidence in this scenario remains too low to include probabilities at this time, but may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Thu Jul 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... A weak upper trough will migrate across the Midwest early in the forecast period. However, weak deep-layer flow and relatively modest large-scale ascent may limit severe potential. Generally low-amplitude upper troughing will then prevail across the eastern third of the CONUS through much of the work week. Meanwhile, an expansive upper ridge centered over the Rockies/High Plains vicinity will persist for much of the Day 4-8 period. Some severe potential is possible in a northwesterly flow regime over the Mid-MO to Mid-MS Valley around Days 5-6/Mon-Tue, but this risk would largely be driven by mesoscale factors not well resolved at longer time periods. Late in the period, forecast guidance suggests a shortwave trough may develop eastward atop the upper ridge in the vicinity of the northern Plains. This break down of the upper ridge amid a very moist and unstable boundary layer would be a favorable pattern for potential MCS development around Day 7 or 8/Wed or Thu. Confidence in this scenario remains too low to include probabilities at this time, but may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Thu Jul 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... A weak upper trough will migrate across the Midwest early in the forecast period. However, weak deep-layer flow and relatively modest large-scale ascent may limit severe potential. Generally low-amplitude upper troughing will then prevail across the eastern third of the CONUS through much of the work week. Meanwhile, an expansive upper ridge centered over the Rockies/High Plains vicinity will persist for much of the Day 4-8 period. Some severe potential is possible in a northwesterly flow regime over the Mid-MO to Mid-MS Valley around Days 5-6/Mon-Tue, but this risk would largely be driven by mesoscale factors not well resolved at longer time periods. Late in the period, forecast guidance suggests a shortwave trough may develop eastward atop the upper ridge in the vicinity of the northern Plains. This break down of the upper ridge amid a very moist and unstable boundary layer would be a favorable pattern for potential MCS development around Day 7 or 8/Wed or Thu. Confidence in this scenario remains too low to include probabilities at this time, but may become necessary in subsequent outlooks. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0208 AM CDT Thu Jul 25 2024 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS VICINITY... ...SUMMARY... Strong to severe thunderstorms are possible across portions of the northern Plains vicinity on Saturday. ...Northern Plains... An upper low will be centered over northern Saskatchewan/Manitoba on Saturday, with the associated northern stream upper trough extending southwest from the upper low into MT. The northern stream trough will develop east across the Canadian Prairies, clipping the northern Plains. Meanwhile, another convectively enhanced shortwave impulse embedded in westerly flow will migrate eastward across WY into the SD/NE vicinity. At the surface, a cold front is forecast to shift southeast across the northern Plains during the evening/overnight hours. Ahead of the front, south/southeasterly low-level flow will aid in northeastward transport of richer boundary layer moisture. Convection will likely develop ahead of the cold front in ND during the evening and into the overnight hours. Additional thunderstorm clusters related to the shortwave impulse emanating out of WY are expected by late afternoon/early evening. Aided by 30-40 kt southerly low-level jet, this activity may also form upscale into an eastward propagating MCS across parts of SD/NE. At least isolated severe thunderstorms appear possible given favorable thermodynamic profiles and effective shear magnitudes greater than 30 kt. Timing of shortwave trough ejection and surface cold front position, as well as questions regarding a recovering airmass in the wake of an early day exiting shortwave trough still lend to plenty of uncertainty for the Day 3/Saturday period. However, greater severe probabilities may be needed in subsequent outlooks as these finer scale details become better resolved in the coming days. ..Leitman.. 07/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0208 AM CDT Thu Jul 25 2024 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS VICINITY... ...SUMMARY... Strong to severe thunderstorms are possible across portions of the northern Plains vicinity on Saturday. ...Northern Plains... An upper low will be centered over northern Saskatchewan/Manitoba on Saturday, with the associated northern stream upper trough extending southwest from the upper low into MT. The northern stream trough will develop east across the Canadian Prairies, clipping the northern Plains. Meanwhile, another convectively enhanced shortwave impulse embedded in westerly flow will migrate eastward across WY into the SD/NE vicinity. At the surface, a cold front is forecast to shift southeast across the northern Plains during the evening/overnight hours. Ahead of the front, south/southeasterly low-level flow will aid in northeastward transport of richer boundary layer moisture. Convection will likely develop ahead of the cold front in ND during the evening and into the overnight hours. Additional thunderstorm clusters related to the shortwave impulse emanating out of WY are expected by late afternoon/early evening. Aided by 30-40 kt southerly low-level jet, this activity may also form upscale into an eastward propagating MCS across parts of SD/NE. At least isolated severe thunderstorms appear possible given favorable thermodynamic profiles and effective shear magnitudes greater than 30 kt. Timing of shortwave trough ejection and surface cold front position, as well as questions regarding a recovering airmass in the wake of an early day exiting shortwave trough still lend to plenty of uncertainty for the Day 3/Saturday period. However, greater severe probabilities may be needed in subsequent outlooks as these finer scale details become better resolved in the coming days. ..Leitman.. 07/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0208 AM CDT Thu Jul 25 2024 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS VICINITY... ...SUMMARY... Strong to severe thunderstorms are possible across portions of the northern Plains vicinity on Saturday. ...Northern Plains... An upper low will be centered over northern Saskatchewan/Manitoba on Saturday, with the associated northern stream upper trough extending southwest from the upper low into MT. The northern stream trough will develop east across the Canadian Prairies, clipping the northern Plains. Meanwhile, another convectively enhanced shortwave impulse embedded in westerly flow will migrate eastward across WY into the SD/NE vicinity. At the surface, a cold front is forecast to shift southeast across the northern Plains during the evening/overnight hours. Ahead of the front, south/southeasterly low-level flow will aid in northeastward transport of richer boundary layer moisture. Convection will likely develop ahead of the cold front in ND during the evening and into the overnight hours. Additional thunderstorm clusters related to the shortwave impulse emanating out of WY are expected by late afternoon/early evening. Aided by 30-40 kt southerly low-level jet, this activity may also form upscale into an eastward propagating MCS across parts of SD/NE. At least isolated severe thunderstorms appear possible given favorable thermodynamic profiles and effective shear magnitudes greater than 30 kt. Timing of shortwave trough ejection and surface cold front position, as well as questions regarding a recovering airmass in the wake of an early day exiting shortwave trough still lend to plenty of uncertainty for the Day 3/Saturday period. However, greater severe probabilities may be needed in subsequent outlooks as these finer scale details become better resolved in the coming days. ..Leitman.. 07/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0208 AM CDT Thu Jul 25 2024 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS VICINITY... ...SUMMARY... Strong to severe thunderstorms are possible across portions of the northern Plains vicinity on Saturday. ...Northern Plains... An upper low will be centered over northern Saskatchewan/Manitoba on Saturday, with the associated northern stream upper trough extending southwest from the upper low into MT. The northern stream trough will develop east across the Canadian Prairies, clipping the northern Plains. Meanwhile, another convectively enhanced shortwave impulse embedded in westerly flow will migrate eastward across WY into the SD/NE vicinity. At the surface, a cold front is forecast to shift southeast across the northern Plains during the evening/overnight hours. Ahead of the front, south/southeasterly low-level flow will aid in northeastward transport of richer boundary layer moisture. Convection will likely develop ahead of the cold front in ND during the evening and into the overnight hours. Additional thunderstorm clusters related to the shortwave impulse emanating out of WY are expected by late afternoon/early evening. Aided by 30-40 kt southerly low-level jet, this activity may also form upscale into an eastward propagating MCS across parts of SD/NE. At least isolated severe thunderstorms appear possible given favorable thermodynamic profiles and effective shear magnitudes greater than 30 kt. Timing of shortwave trough ejection and surface cold front position, as well as questions regarding a recovering airmass in the wake of an early day exiting shortwave trough still lend to plenty of uncertainty for the Day 3/Saturday period. However, greater severe probabilities may be needed in subsequent outlooks as these finer scale details become better resolved in the coming days. ..Leitman.. 07/25/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CDT Thu Jul 25 2024 Valid 261200Z - 271200Z ...Synopsis... As a mid-level shortwave trough moves onshore to the California coast and into Nevada tomorrow, isolated dry thunderstorms are expected across northern Utah into southeastern Idaho and southwestern Wyoming. Elevated fire-weather conditions are also expected across portions of the Northwest, including northern California into southwestern Oregon, western portions of the Upper Snake River Region in Idaho, and far northern Montana. ...Northern Utah into Southern Idaho and Southwestern Wyoming... Isolated dry thunderstorms are expected as a mid-level trough and associated jet streak approaches the California coast. Hot, dry boundary-layer profiles, coupled with 35-40 kt mean wind speed estimates for storm motions, will result in little wetting rainfall occurring over receptive fuels. A mix of dry and wet thunderstorms are possible further into Wyoming, but fuels in the region are less receptive to ignitions. There may be a chance for isolated dry thunderstorms in far southern Montana, but the threat appears to be too localized to include a highlight area at this time. ...Northwest... Elevated fire-weather conditions will persist across portions of southern Oregon and into northwestern California with the approaching trough. The strongest winds will likely be confined to the Fremont mountains and Modoc Plateau. Portions of northern Montana could also see elevated fire-weather conditions on Friday, where prolonged dry and windy conditions will overlap with receptive fuels as a mid-level jet extending from Saskatchewan into Montana begins to exit the region and progress eastward. The most pronounced region for elevated conditions is expected to be across portions of the Snake River Plain and into the Upper Snake Region, where there is significant overlap between 20-25 kt surface winds, < 15% RH, and receptive fuels. ..Halbert/Lyons.. 07/25/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more