Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

No watches are valid as of Wed Aug 13 20:17:01 UTC 2025.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 13 2025 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH DAKOTA AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Scattered severe wind gusts and isolated large hail may occur across parts of the northern/central Plains this evening and overnight. Thunderstorms across portions of the Northeast and Mid-Atlantic may produce occasional damaging winds this afternoon. ...20Z Update... The western portion of the Marginal Risk area in the Mid-Atlantic was trimmed, where convective overturning and cloud debris should generally limit the severe risk. Farther west, the Marginal Risk was expanded slightly northward into southwestern ND. Recent high-resolution guidance is in relatively good agreement, depicting a cluster of high-based storms evolving in an environment characterized by weak-moderate surface-based buoyancy and 30-40 kt of effective shear. Severe wind gusts and isolated large hail will be possible with these storms. For details on the near-term severe risk in the northern Plains, see MCD #1939. ..Weinman.. 08/13/2025 .PREV DISCUSSION... /ISSUED 1146 AM CDT Wed Aug 13 2025/ ...Northern/Central Plains... Recent satellite imagery shows a low-amplitude shortwave trough moving through southwest MT. This shortwave is forecast to continue eastward along the MT/WY border vicinity today, before continuing through the Dakotas/NE tonight. The airmass preceding this shortwave across southeast MT/northeast WY is relatively dry, with dewpoints currently in the low to mid 50s. Greater low-level moisture is in place farther east, with dewpoints increasing into the low 60s across south-central SD and north-central NE. Southerly low-level flow is anticipated throughout the day, helping to offset some of the mixing expected amid strong diurnal heating. This should result in a modestly moist, deeply mixed airmass across the southeast MT/northeast WY/western SD vicinity by the late afternoon when the forcing for ascent attendant to the approaching shortwave reaches the region. This modest large-scale ascent show work in tandem with robust daytime heating and localized orographic effects near the Black Hills to initiate thunderstorms. High-based storms are anticipated initially, which could result in strong outflow with any more mature storms. A few instances of hail as possible as well. Greater low-level moisture and buoyancy will be in place farther east (i.e. into more of western/central SD), which will combine with persistent large-scale forcing for ascent and a strengthening low-level jet to support upscale growth into a convective line. This should foster a continued threat for damaging gusts into south-central SD and far north-central NE this evening. The threat should diminish with eastern extent given nocturnal stabilization and increasing convective inhibition. ...Northeast/Mid-Atlantic... Dewpoints currently range from the low 70s over the northern Mid-Atlantic into the low 60s across northern NH/VT. Thunderstorms are already developing within this moist and moderately buoyant airmass as large-scale ascent attendant to upper troughing advancing eastward over Ontario/Quebec glances the region. Deep-layer vertical shear is expected to remain weak throughout the day (i.e. effective bulk shear generally less than 25 kt), which should limit overall storm strength and organization. Even so, steep low-level lapse rates could aid in the development of occasionally damaging gusts with any of the deeper convective cores. Greater buoyancy could result in a relatively higher probability for damaging gusts from the NY Hudson Valley into eastern PA/NJ. Refer to recently issued MCD #1938 for additional information. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...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 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more