SPC Feb 12, 2025 0100 UTC Day 1 Convective Outlook

5 months 2 weeks ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 PM CST Tue Feb 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH TEXAS INTO SOUTHEAST TEXAS AND FAR WESTERN LOUISIANA... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of the Texas-Louisiana border vicinity through tonight. ...TX into LA... Early evening surface analysis places a front across south Texas into the coastal shelf waters south of Galveston Bay and into south-central LA. Water-vapor imagery shows a mid-level shortwave trough moving quickly east across northwestern Mexico and through the base of a larger scale trough over western North America. This mid-level disturbance is forecast to move into central TX by 12/09z and east TX by mid morning tomorrow. A corresponding intensification of flow fields and QG ascent is expected late tonight across south TX and eventually near the Sabine Valley towards 12/12z. Steep 700-500 mb lapse rates (reference 7.3 deg C/km on the 12/00z Corpus Christi, TX upper-air sounding) and ample moisture will facilitate storm development later tonight. Model guidance shows showers and thunderstorms beginning initially near the Rio Grande and spreading east while increasing in coverage. A few of the stronger storms may exhibit rotation and perhaps yield an isolated risk for hail/wind. Elsewhere, the northeast extent of the TX frontal zone is located over the central Gulf Coast this evening. The gradual diminishing of instability and convergence with the front will likely promote continued weakening of convection this evening from the central Gulf Coast into central AL. Have removed low-severe probabilities to account for this observed and likely continuation of storm weakening in the short term. ..Smith.. 02/12/2025 Read more

SPC Feb 12, 2025 0100 UTC Day 1 Convective Outlook

5 months 2 weeks ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 PM CST Tue Feb 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH TEXAS INTO SOUTHEAST TEXAS AND FAR WESTERN LOUISIANA... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of the Texas-Louisiana border vicinity through tonight. ...TX into LA... Early evening surface analysis places a front across south Texas into the coastal shelf waters south of Galveston Bay and into south-central LA. Water-vapor imagery shows a mid-level shortwave trough moving quickly east across northwestern Mexico and through the base of a larger scale trough over western North America. This mid-level disturbance is forecast to move into central TX by 12/09z and east TX by mid morning tomorrow. A corresponding intensification of flow fields and QG ascent is expected late tonight across south TX and eventually near the Sabine Valley towards 12/12z. Steep 700-500 mb lapse rates (reference 7.3 deg C/km on the 12/00z Corpus Christi, TX upper-air sounding) and ample moisture will facilitate storm development later tonight. Model guidance shows showers and thunderstorms beginning initially near the Rio Grande and spreading east while increasing in coverage. A few of the stronger storms may exhibit rotation and perhaps yield an isolated risk for hail/wind. Elsewhere, the northeast extent of the TX frontal zone is located over the central Gulf Coast this evening. The gradual diminishing of instability and convergence with the front will likely promote continued weakening of convection this evening from the central Gulf Coast into central AL. Have removed low-severe probabilities to account for this observed and likely continuation of storm weakening in the short term. ..Smith.. 02/12/2025 Read more

SPC MD 82

5 months 2 weeks ago
MD 0082 CONCERNING HEAVY SNOW FOR PARTS OF THE MID-ATLANTIC
Mesoscale Discussion 0082 NWS Storm Prediction Center Norman OK 0149 PM CST Tue Feb 11 2025 Areas affected...parts of the Mid-Atlantic Concerning...Heavy snow Valid 111949Z - 112345Z SUMMARY...A band of heavy snow developing across the Mid-Atlantic region will be capable of moderate to heavy snowfall rates upwards of 1-2 inches per hour. Similar bands and snowfall rates will be possible through early evening. DISCUSSION...Regional radar imagery shows an organized precipitation/snow band developing from west-central VA into the Chesapeake Bay area. Recent snowfall reports from central VA and surface observations reporting visibility reductions between 0.25 to 0.5 mile suggest moderate to heavy snowfall rates are ongoing. This band is largely being driven by a combination of strong warm-air advection and frontogenesis within the 925-700 mb layer and may persist for another hour or two given the strength of forcing for ascent. Additional banding is possible heading into the late afternoon hours as a weak mid-level impulse - and the primary precipitation shield - migrates into the region and to the north/northeast into northern MD and DE. Recent guidance suggests heavy snow potential will likely peak across the Chesapeake Bay area during the 21-00 UTC period. Although surface temperatures across this region remain near/above freezing, dewpoints in the 20s suggest that temperatures will likely fall to below freezing due to low-level evaporative cooling associated with the onset of precipitation, which should support heavier snowfall rates later this afternoon. ..Moore.. 02/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...AKQ...LWX... LAT...LON 39697503 39597727 39497808 39297861 39027876 38647871 38157822 37727772 37477737 37357681 37327624 37597546 37947527 38287504 38927472 39397424 39607435 39667473 39697503 Read more

SPC MD 81

5 months 2 weeks ago
MD 0081 CONCERNING FREEZING RAIN FOR FAR NORTHWEST NORTH CAROLINA...EASTERN WEST VIRGINIA...AND WESTERN TO CENTRAL VIRGINIA
Mesoscale Discussion 0081 NWS Storm Prediction Center Norman OK 1126 AM CST Tue Feb 11 2025 Areas affected...Far northwest North Carolina...eastern West Virginia...and western to central Virginia Concerning...Freezing rain Valid 111726Z - 112230Z SUMMARY...Freezing rain is expected to become more widespread in the lee of the Blue Ridge Mountains across far northwest North Carolina, far eastern West Virginia, and western to central Virginia through the afternoon hours. Freezing rain rates up to 0.02 to 0.04 in/hour appear likely. DISCUSSION...A broad swath of stratiform precipitation (largely driven by strong warm advection between 925-700 mb) continues to spread east/northeast across the TN Valley and into the southern/central Appalachians. Sub-freezing temperatures throughout the column this morning across WV/VA have resulted in several inches of snowfall per recent reports. However, mPING reports of sleet across northern NC/southern VA suggest that the 925-850 mb freezing lines are beginning to migrate northward. This trend is expected to continue through the afternoon hours as a subtle mid-level impulse (currently over the Mid-South) continues to propagate northeast along the mid-level baroclinic zone and augments southerly flow/warm air advection. This will result in gradually warming mid-level temperatures as the primary precipitation shield shifts east. At the surface, cold air damming along the lee of the Blue Ridge Mountains, combined with very limited diurnal heating and low-level wet-bulb cooling, has maintained sub-freezing temperatures from far northwest NC into VA. Although surface temperatures in 12 UTC guidance appear to be running too warm compared to 17 UTC observations, recent RAP/HRRR solutions have captured temperature trends well and suggest a transition from snow to sleet, and eventually freezing rain, will begin by around 18 UTC in the immediate lee of the higher terrain. Sleet/freezing rain should spread east through the afternoon with freezing rain rates between 0.02 to 0.04 in/hour likely for most locations (though locally higher rates are possible). ..Moore.. 02/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX...RNK...RLX...GSP...MRX... LAT...LON 36018168 36048189 36138204 36288208 37188155 37598122 38158082 38368054 38548010 38587977 38537922 38397875 38027804 37717768 37467757 37277762 37147771 37067797 37017821 37037856 37027879 37007932 36927975 36608042 36018168 Read more

SPC Day 3-8 Fire Weather Outlook

5 months 2 weeks ago
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

5 months 2 weeks ago
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

5 months 2 weeks ago
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

5 months 2 weeks ago
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

5 months 2 weeks ago
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

5 months 2 weeks ago
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

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 2000 UTC Day 1 Convective Outlook

5 months 2 weeks ago
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 Feb 11, 2025 1930 UTC Day 3 Severe Thunderstorm Outlook

5 months 2 weeks ago
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