Aggregator

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0649 PM CST Tue Dec 26 2023 Valid 270100Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms will not occur through tonight across the contiguous United States. ...Synopsis... Water-vapor imagery early this evening shows a large gyre centered over the lower MO Valley with weak mid-level ridges located along the East and West coasts. A moist/warm conveyor is located over the Carolinas northward into the upper OH Valley, where scant buoyancy was observed (i.e., Carolinas per 00z raob data) or forecast later tonight. This weak instability may lead to a few widely spaced, isolated lightning flashes tonight over the Carolinas, and perhaps as far north as the upper OH Valley. Elsewhere, cool and/or stable conditions will preclude thunderstorm development across the CONUS. ..Smith.. 12/27/2023 Read more

No Mesoscale Discussions are in effect as of Tue Dec 26 22:13:02 UTC 2023.

No watches are valid as of Tue Dec 26 22:13:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 26 2023 Valid 281200Z - 031200Z The potential for critical fire-weather conditions is low through the extended forecast period. On D4/Friday, a persistent midlevel low will gradually devolve into a positive-tilt trough over the eastern CONUS, while a related southwesterly jet streak overspreads the Southeast and Mid-Atlantic. A modest pressure gradient beneath the strong flow aloft will favor breezy/gusty surface winds across much of the Southeast into the southern Mid-Atlantic states, where marginal RH reductions are possible. However, generally cool surface temperatures and recent/ongoing rainfall should limit most fire-weather concerns here. Thereafter, an unconsolidated/split-flow pattern is expected across the CONUS, which will generally limit the development/overlap of warm/dry/windy conditions. One exception may be on D6/Sunday across the southern High Plains, where a southern-stream jet max may promote dry/breezy downslope flow. With that said, critical conditions are unlikely owing to marginal fuels. ..Weinman.. 12/26/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 26 2023 Valid 281200Z - 031200Z The potential for critical fire-weather conditions is low through the extended forecast period. On D4/Friday, a persistent midlevel low will gradually devolve into a positive-tilt trough over the eastern CONUS, while a related southwesterly jet streak overspreads the Southeast and Mid-Atlantic. A modest pressure gradient beneath the strong flow aloft will favor breezy/gusty surface winds across much of the Southeast into the southern Mid-Atlantic states, where marginal RH reductions are possible. However, generally cool surface temperatures and recent/ongoing rainfall should limit most fire-weather concerns here. Thereafter, an unconsolidated/split-flow pattern is expected across the CONUS, which will generally limit the development/overlap of warm/dry/windy conditions. One exception may be on D6/Sunday across the southern High Plains, where a southern-stream jet max may promote dry/breezy downslope flow. With that said, critical conditions are unlikely owing to marginal fuels. ..Weinman.. 12/26/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 26 2023 Valid 281200Z - 031200Z The potential for critical fire-weather conditions is low through the extended forecast period. On D4/Friday, a persistent midlevel low will gradually devolve into a positive-tilt trough over the eastern CONUS, while a related southwesterly jet streak overspreads the Southeast and Mid-Atlantic. A modest pressure gradient beneath the strong flow aloft will favor breezy/gusty surface winds across much of the Southeast into the southern Mid-Atlantic states, where marginal RH reductions are possible. However, generally cool surface temperatures and recent/ongoing rainfall should limit most fire-weather concerns here. Thereafter, an unconsolidated/split-flow pattern is expected across the CONUS, which will generally limit the development/overlap of warm/dry/windy conditions. One exception may be on D6/Sunday across the southern High Plains, where a southern-stream jet max may promote dry/breezy downslope flow. With that said, critical conditions are unlikely owing to marginal fuels. ..Weinman.. 12/26/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 26 2023 Valid 281200Z - 031200Z The potential for critical fire-weather conditions is low through the extended forecast period. On D4/Friday, a persistent midlevel low will gradually devolve into a positive-tilt trough over the eastern CONUS, while a related southwesterly jet streak overspreads the Southeast and Mid-Atlantic. A modest pressure gradient beneath the strong flow aloft will favor breezy/gusty surface winds across much of the Southeast into the southern Mid-Atlantic states, where marginal RH reductions are possible. However, generally cool surface temperatures and recent/ongoing rainfall should limit most fire-weather concerns here. Thereafter, an unconsolidated/split-flow pattern is expected across the CONUS, which will generally limit the development/overlap of warm/dry/windy conditions. One exception may be on D6/Sunday across the southern High Plains, where a southern-stream jet max may promote dry/breezy downslope flow. With that said, critical conditions are unlikely owing to marginal fuels. ..Weinman.. 12/26/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Tue Dec 26 2023 Valid 262000Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. No changes are required to the existing outlook, with only general thunderstorms expected over parts of the Southeast. ..Jewell.. 12/26/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Tue Dec 26 2023/ ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Tue Dec 26 2023 Valid 262000Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. No changes are required to the existing outlook, with only general thunderstorms expected over parts of the Southeast. ..Jewell.. 12/26/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Tue Dec 26 2023/ ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Tue Dec 26 2023 Valid 262000Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. No changes are required to the existing outlook, with only general thunderstorms expected over parts of the Southeast. ..Jewell.. 12/26/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Tue Dec 26 2023/ ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Tue Dec 26 2023 Valid 262000Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. No changes are required to the existing outlook, with only general thunderstorms expected over parts of the Southeast. ..Jewell.. 12/26/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Tue Dec 26 2023/ ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1108 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few non-severe thunderstorms are possible over parts of the Mid Atlantic during the day on Wednesday. ...Synopsis and Discussion... A deep upper low will fill slightly as it moves slowly east across the lower MS Valley, with a large area of cyclonic flow aloft over the Plains, MS Valley and Southeast. Relatively cool air will remain over much of the Plains with northerly winds extending into the western Gulf of Mexico, but a weak surface low will develop over NC in a zone of warm southeasterlies well ahead of the upper low. Extensive clouds and precipitation will limit destabilization as well as low-level lapse rates over NC and southern VA where MUCAPE may approach 500 J/kg. However, this will be sufficient to support scattered convection within the larger area of precipitation, by virtue of cool midlevel temperatures and mainly early in the day prior to drier air pushing in from the west as 850 mb winds veer. While forecast soundings over NC do show surface-based parcel potential, real boundary-layer buoyancy will be limited by the poor lapse rates/saturated profiles in a weak forcing regime. Therefore, despite veering winds with height and effective SRH values of 200-300 m2/s2, severe weather remains unlikely. ..Jewell.. 12/26/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1108 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few non-severe thunderstorms are possible over parts of the Mid Atlantic during the day on Wednesday. ...Synopsis and Discussion... A deep upper low will fill slightly as it moves slowly east across the lower MS Valley, with a large area of cyclonic flow aloft over the Plains, MS Valley and Southeast. Relatively cool air will remain over much of the Plains with northerly winds extending into the western Gulf of Mexico, but a weak surface low will develop over NC in a zone of warm southeasterlies well ahead of the upper low. Extensive clouds and precipitation will limit destabilization as well as low-level lapse rates over NC and southern VA where MUCAPE may approach 500 J/kg. However, this will be sufficient to support scattered convection within the larger area of precipitation, by virtue of cool midlevel temperatures and mainly early in the day prior to drier air pushing in from the west as 850 mb winds veer. While forecast soundings over NC do show surface-based parcel potential, real boundary-layer buoyancy will be limited by the poor lapse rates/saturated profiles in a weak forcing regime. Therefore, despite veering winds with height and effective SRH values of 200-300 m2/s2, severe weather remains unlikely. ..Jewell.. 12/26/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1108 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few non-severe thunderstorms are possible over parts of the Mid Atlantic during the day on Wednesday. ...Synopsis and Discussion... A deep upper low will fill slightly as it moves slowly east across the lower MS Valley, with a large area of cyclonic flow aloft over the Plains, MS Valley and Southeast. Relatively cool air will remain over much of the Plains with northerly winds extending into the western Gulf of Mexico, but a weak surface low will develop over NC in a zone of warm southeasterlies well ahead of the upper low. Extensive clouds and precipitation will limit destabilization as well as low-level lapse rates over NC and southern VA where MUCAPE may approach 500 J/kg. However, this will be sufficient to support scattered convection within the larger area of precipitation, by virtue of cool midlevel temperatures and mainly early in the day prior to drier air pushing in from the west as 850 mb winds veer. While forecast soundings over NC do show surface-based parcel potential, real boundary-layer buoyancy will be limited by the poor lapse rates/saturated profiles in a weak forcing regime. Therefore, despite veering winds with height and effective SRH values of 200-300 m2/s2, severe weather remains unlikely. ..Jewell.. 12/26/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1108 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few non-severe thunderstorms are possible over parts of the Mid Atlantic during the day on Wednesday. ...Synopsis and Discussion... A deep upper low will fill slightly as it moves slowly east across the lower MS Valley, with a large area of cyclonic flow aloft over the Plains, MS Valley and Southeast. Relatively cool air will remain over much of the Plains with northerly winds extending into the western Gulf of Mexico, but a weak surface low will develop over NC in a zone of warm southeasterlies well ahead of the upper low. Extensive clouds and precipitation will limit destabilization as well as low-level lapse rates over NC and southern VA where MUCAPE may approach 500 J/kg. However, this will be sufficient to support scattered convection within the larger area of precipitation, by virtue of cool midlevel temperatures and mainly early in the day prior to drier air pushing in from the west as 850 mb winds veer. While forecast soundings over NC do show surface-based parcel potential, real boundary-layer buoyancy will be limited by the poor lapse rates/saturated profiles in a weak forcing regime. Therefore, despite veering winds with height and effective SRH values of 200-300 m2/s2, severe weather remains unlikely. ..Jewell.. 12/26/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1108 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few non-severe thunderstorms are possible over parts of the Mid Atlantic during the day on Wednesday. ...Synopsis and Discussion... A deep upper low will fill slightly as it moves slowly east across the lower MS Valley, with a large area of cyclonic flow aloft over the Plains, MS Valley and Southeast. Relatively cool air will remain over much of the Plains with northerly winds extending into the western Gulf of Mexico, but a weak surface low will develop over NC in a zone of warm southeasterlies well ahead of the upper low. Extensive clouds and precipitation will limit destabilization as well as low-level lapse rates over NC and southern VA where MUCAPE may approach 500 J/kg. However, this will be sufficient to support scattered convection within the larger area of precipitation, by virtue of cool midlevel temperatures and mainly early in the day prior to drier air pushing in from the west as 850 mb winds veer. While forecast soundings over NC do show surface-based parcel potential, real boundary-layer buoyancy will be limited by the poor lapse rates/saturated profiles in a weak forcing regime. Therefore, despite veering winds with height and effective SRH values of 200-300 m2/s2, severe weather remains unlikely. ..Jewell.. 12/26/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Tue Dec 26 2023 Valid 261630Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. ..Mosier/Thornton.. 12/26/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Tue Dec 26 2023 Valid 261630Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. ..Mosier/Thornton.. 12/26/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Tue Dec 26 2023 Valid 261630Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. ..Mosier/Thornton.. 12/26/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Tue Dec 26 2023 Valid 261630Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, mature mid-latitude cyclone is centered over the eastern NE/KS border vicinity. This cyclone is expected to move gradually into MO, while becoming increasingly vertically stacked with time. Cold and dry air mass associated with this cyclone will dominant the sensible weather across much of the CONUS. The only exception is from the coastal Southeast through the Mid-Atlantic States. Here, an extensive warm conveyor, originating over central Mexico and the western Gulf of Mexico and splitting over the Mid-Atlantic, will contribute to broad isentropic ascent. Strongest ascent is ongoing over the SC vicinity, where enhanced low-level southeasterly flow is augmenting the modest ascent within the warm conveyor. This low-level flow is forecast to continue throughout the period while gradually shifting northward, resulting in prolonged isentropic ascent and a continued threat for isolated thunderstorms embedded within the broader precipitation shield. Highest thunderstorm coverage is expected over the western Carolinas. Some favorable low-level shear may exist across the central/eastern Carolinas, but this shear should be displaced west of any surface-based buoyancy, limiting the severe potential. ..Mosier/Thornton.. 12/26/2023 Read more