Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Tue Dec 12 2023 Valid 122000Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through daybreak Wednesday. ...20Z Update... Forecast soundings suggest that moistening supportive of very weak CAPE across the Texas South Plains vicinity tonight will be largely rooted near or above 700 mb. The extent of any potential for warm advection driven convection to produce lightning remains unclear. However, the categorical thunderstorm line (10 percent probability) has been adjusted somewhat, to focus where latest model output suggests that weak mid-level ascent and slightly cooler mid-level temperatures might contribute to thermodynamic profiles most conducive to lightning. ..Kerr.. 12/12/2023 .PREV DISCUSSION... /ISSUED 1013 AM CST Tue Dec 12 2023/ ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1243 PM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast remains on track with minimal fire weather potential expected over most of the CONUS for Wednesday. Details in the previous discussion (below) outlining concerns for southern California remain valid based on recent observations and trends in recent guidance. ..Moore.. 12/12/2023 .PREV DISCUSSION... /ISSUED 0150 AM CST Tue Dec 12 2023/ ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ...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 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Wednesday through Wednesday night. ...Synopsis... Cool, generally dry and stable air prevails, particularly under the influence of expansive surface ridging across the northern U.S. Intermountain West through most areas east of the Rockies. An increasingly prominent embedded center of higher pressure within this regime is forecast to gradually shift across the middle Mississippi through lower Ohio Valleys during this period, beneath confluent flow in the wake of a mid-level short wave trough digging across the Great Lakes and northern Mid Atlantic region. However, models indicate that the southern/southwestern periphery of this ridging will be maintained across much of the northern Gulf of Mexico and southern Great Plains, beneath the leading edge of large-scale mid-level ridging, which will continue to spread inland of the Pacific coast through much of the Mississippi Valley. Weak mid-level troughing, within the larger-scale ridge, is forecast to slowly pivot across the Intermountain West and Rockies, with an embedded mid-level low digging into the Mogollon Rim vicinity of the Southwest, before slowly turning eastward toward the southern Rockies by late Wednesday night. ...Four Corners region into southern Great Plains... Elevated moisture return and lift associated with warm advection, in advance of the developing mid-level low, may contribute to sufficient destabilization to support increasing convection across parts of the Texas South Plains into Panhandle region by 12Z Wednesday. Some of this may become capable of producing lightning, before at least some further destabilization, beneath increasingly divergent mid/upper flow, contributes to a more substantive increase in weak thunderstorm development near/east of the New Mexico Sangre de Cristo Mountains by late Wednesday afternoon, then into the Texas Panhandle and South Plains vicinity through 12Z Thursday. Closer to the cold core of the mid-level low, models indicate that weak boundary-layer destabilization is possible across the plateau and Mogollon Rim vicinity of eastern Arizona into adjacent western New Mexico by late Wednesday afternoon. Aided by strengthening mid/upper forcing for ascent, this may lead to increasing thunderstorm development which may persist into mid/late evening. While the risk for severe storms appears negligible, thermodynamic profiles might still become conducive to small hail/graupel in stronger convection. ...Southern Florida... While northeasterly to east-northeasterly low-level flow is likely to be maintained through the period, models indicate that low-level moistening might contribute to sufficient destabilization to support occasional weak thunderstorm activity, mainly where low-level convergence remains enhanced near/offshore of southeast coastal areas. ..Kerr.. 12/12/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1013 AM CST Tue Dec 12 2023 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. ..Leitman/Weinman.. 12/12/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1013 AM CST Tue Dec 12 2023 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... No changes to the ongoing outlook are needed with the 1630z update. Moistening midlevels and steepening lapse rates ahead of the western U.S. upper trough will foster modest elevated instability overnight across eastern NM/west TX. Increasing ascent in a continued warm advection regime may be sufficient for a few lightning flashes in elevated convective showers. Severe storms are not expected. ..Leitman/Weinman.. 12/12/2023 Read more