Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0136 PM CST Mon Dec 23 2024 Valid 232000Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. Only minor changes have been made to the ongoing thunderstorm forecast for the southern Plains, based on recent CAM guidance. Please see previous discussion for more details. ..Hart.. 12/23/2024 .PREV DISCUSSION... /ISSUED 1017 AM CST Mon Dec 23 2024/ ...Synopsis... A modifying air mass is returning northward into TX from the western Gulf basin, and continued low-level warming/moistening will result in gradual destabilization. Modest amplification of a midlevel trough over the southern High Plains, in combination with an increasingly moist warm advection regime, will support the potential for a few elevated thunderstorms this evening into tonight across parts of OK/north TX. There is also a small chance for near-surface-based thunderstorms along a confluence zone from Matagorda Bay northward into the western parts of southeast TX. Otherwise, a midlevel trough over the eastern Pacific will approach northern CA late in the period, when weak destabilization could support sufficiently deep convection for isolated lightning flashes. Farther east, the potential for deep convection will increase through the period in association with air mass modification and weak cyclogenesis in the vicinity of the Gulf Stream. However, the potential for thunderstorms is expected to remain offshore. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0136 PM CST Mon Dec 23 2024 Valid 232000Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. Only minor changes have been made to the ongoing thunderstorm forecast for the southern Plains, based on recent CAM guidance. Please see previous discussion for more details. ..Hart.. 12/23/2024 .PREV DISCUSSION... /ISSUED 1017 AM CST Mon Dec 23 2024/ ...Synopsis... A modifying air mass is returning northward into TX from the western Gulf basin, and continued low-level warming/moistening will result in gradual destabilization. Modest amplification of a midlevel trough over the southern High Plains, in combination with an increasingly moist warm advection regime, will support the potential for a few elevated thunderstorms this evening into tonight across parts of OK/north TX. There is also a small chance for near-surface-based thunderstorms along a confluence zone from Matagorda Bay northward into the western parts of southeast TX. Otherwise, a midlevel trough over the eastern Pacific will approach northern CA late in the period, when weak destabilization could support sufficiently deep convection for isolated lightning flashes. Farther east, the potential for deep convection will increase through the period in association with air mass modification and weak cyclogenesis in the vicinity of the Gulf Stream. However, the potential for thunderstorms is expected to remain offshore. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more