Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0324 PM CST Tue Feb 11 2025 Valid 131200Z - 191200Z ...Synopsis... By the end of Day 3/Thursday, a longwave trough is expected to be over the northeastern CONUS while a shortwave trough begins to move onshore near southern CA. This feature will traverse the Southwest and Southern Plains this weekend. Increasing mid-level flow near the base of this trough, and the surface pressure gradient on the western periphery of an associated cyclone, should support breezy west-northwesterly surface winds across much of the Trans-Pecos and the Big Bend of TX Day 5/Saturday. Confidence remains high enough to continue with low critical probabilities within this area, where fuels will likely remain receptive to fire starts. However, some initial cold air advection accompanying a Pacific front may keep RH above critical thresholds and an increase in probabilities has not been considered at this time. A modified Arctic air mass encompassing most of the CONUS east of the Rockies and generally weaker surface winds will limit the overall fire weather threat into Day 6/Sunday. Increasing orthogonal mid-level flow across the southern Rockies D7/Monday, however, will induce lee pressure falls. A return to relatively dry southerly surface winds across the Southern Plains, and increasing westerly downslope over eastern NM and the Trans-Pecos are anticipated by this time. Confidence isn't high enough to warrant low probabilities for these areas yet given the timing and depth of another approaching Pacific shortwave trough, though this area will be monitored in subsequent forecasts. A similar scenario and low confidence may apply to Day 8/Tuesday across far southern NM and the western Trans-Pecos ahead of another cold front. ..Barnes.. 02/11/2025 ...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 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CST Tue Feb 11 2025 Valid 112000Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH TEXAS AND THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...20z Update... The prior forecast remains largely unchanged with minor adjustments to the thunder area. A well-defined cold front, quickly moving over the southern Plains and western MS valley, will likely continue to undercut the modified Gulf air mass over parts over southern TX. Increasing large-scale ascent over the western edge of the moist sector and cold front will support a gradual increase in convective coverage over south-central and west TX this evening and into the overnight hours. Weak to moderate elevated buoyancy and 40-50 kt of effective shear could support a few organized elevated supercell or bowing structures with a risk of hail or an isolated damaging gust over south TX tonight. Weak buoyancy will also likely extend across northern OK and the Ozarks supporting a risk for scattered thunderstorms. Have extended the thunder area farther northeast for lightning potential late tonight. Across the southeast, recent model guidance suggests storms may persist a bit farther east into parts of AL/GA. While buoyancy will be very weak, inland advection of upper 50s to low 60s F dewpoints could sustain some elevated thunder potential late tonight. ..Lyons.. 02/11/2025 .PREV DISCUSSION... /ISSUED 1029 AM CST Tue Feb 11 2025/ ...South TX to MS/AL through tonight... Clusters of thunderstorms are ongoing near a surface cold front in the Houston area, on the edge of surface temperatures in the low 70s with dewpoints near 70 F. The proximity VWP from HGX shows modest low-level shear/hodograph curvature and stronger flow above 5 km AGL, with some potential for organized storm structures within the band. However, the cold front is also tending to undercut the storms, which casts doubt on the severe storm potential in the short term. Farther east, warming temperatures in cloud breaks and a gradual increase in low-level moisture will result in modest destabilization through the afternoon. 12z regional soundings suggest that midlevel lapse rates will remain relatively poor, though surface temperatures of 75-80 F and boundary-layer dewpoints in the mid 60s will drive MLCAPE of 500-1000 J/kg. Shallow convection is likely in the open warm sector, but thunderstorm potential will be focused along the front where low-level ascent will be maximized later this afternoon/evening. Assuming a couple of storms can form along the front, there will be the potential for isolated wind damage and perhaps a tornado. Overnight, thunderstorm coverage should increase along and immediately north of the front across south central TX, as a midlevel shortwave trough near Baja ejects east-northeastward. Midlevel lapse rates in the 7.5-8.5 C/km range and moistening atop the frontal surface will support MUCAPE near or above 1000 J/kg, while effective bulk shear in excess of 40 kt/long hodographs will be sufficient for elevated organized/supercell storms capable of producing isolated large hail and possibly wind damage. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 PM CST Tue Feb 11 2025 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible early Thursday morning into perhaps the afternoon in parts of the Southeast. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... A strong surface low will deepen across the Northeast early Thursday with a cold front extending along the Appalachians and into the Southeast. An area of high pressure will build into the Plains in the wake of this system with another strong surface low approaching the West Coast. ...Southeast... A line of storms will be ongoing at the beginning of the period from the southern Appalachians to the Florida Panhandle. There may be enough instability for an isolated severe weather threat to persist for a few hours after 12Z, but it is currently unclear where exactly this line of storms will be located at that time. Therefore, no marginal risk will be added this time, but one may be needed if the threat does indeed appear to persist after 12Z and once the exact area of this threat becomes more clear. Farther west, cooling air aloft as a mid-level trough approaches the California coast will result in elevated instability and lightning off the coast and into north-central California. ..Bentley.. 02/11/2025 Read more