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 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

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 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 Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 PM CST Tue Feb 11 2025 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE TRANS-PECOS... A few minor changes were made to the Elevated and Critical areas for Wednesday. Although sustained wind speeds are expected to exceed critical thresholds across portions of the Upper Trans-Pecos and Guadalupe Mountains (20 to 40 mph respectively), relative humidity should generally remain near 25-35 percent. Therefore, the Critical area was trimmed back slightly from its northwestern extent. To the east across portions the Permian Basin, westerly winds exceeding 20 mph will combine with decreasing RH into the teens by Wednesday afternoon. The Elevated area was extended eastward to accommodate these aforementioned conditions, although recent rainfall, less receptive fuels, and good RH recovery further east and south of here should limit the overall fire weather potential. Please see the previous discussion below for additional details. ..Barnes.. 02/11/2025 .PREV DISCUSSION... /ISSUED 0114 AM CST Tue Feb 11 2025/ ...Synopsis... An amplified midlevel trough accompanied by strong westerly flow aloft will overspread the southern Rockies/Plains. At the same time, a related surface low will linger over the southern High Plains ahead of an approaching cold front. ...TX Trans-Pecos... A modest pressure gradient peripheral to the surface low, coupled with boundary-layer mixing into the strong flow aloft, will favor 20-30 mph sustained westerly surface winds (with higher gusts) across southern NM into west TX. Over the TX Trans-Pecos, these winds will combine with 15 percent afternoon RH, and given at least modestly receptive fuels, critical fire-weather conditions are expected. Dry/breezy conditions will extend farther east into portions of central TX, though preceding rainfall atop already marginal fuels should limit fire-weather concerns here. ...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 0100 PM CST Tue Feb 11 2025 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE TRANS-PECOS... A few minor changes were made to the Elevated and Critical areas for Wednesday. Although sustained wind speeds are expected to exceed critical thresholds across portions of the Upper Trans-Pecos and Guadalupe Mountains (20 to 40 mph respectively), relative humidity should generally remain near 25-35 percent. Therefore, the Critical area was trimmed back slightly from its northwestern extent. To the east across portions the Permian Basin, westerly winds exceeding 20 mph will combine with decreasing RH into the teens by Wednesday afternoon. The Elevated area was extended eastward to accommodate these aforementioned conditions, although recent rainfall, less receptive fuels, and good RH recovery further east and south of here should limit the overall fire weather potential. Please see the previous discussion below for additional details. ..Barnes.. 02/11/2025 .PREV DISCUSSION... /ISSUED 0114 AM CST Tue Feb 11 2025/ ...Synopsis... An amplified midlevel trough accompanied by strong westerly flow aloft will overspread the southern Rockies/Plains. At the same time, a related surface low will linger over the southern High Plains ahead of an approaching cold front. ...TX Trans-Pecos... A modest pressure gradient peripheral to the surface low, coupled with boundary-layer mixing into the strong flow aloft, will favor 20-30 mph sustained westerly surface winds (with higher gusts) across southern NM into west TX. Over the TX Trans-Pecos, these winds will combine with 15 percent afternoon RH, and given at least modestly receptive fuels, critical fire-weather conditions are expected. Dry/breezy conditions will extend farther east into portions of central TX, though preceding rainfall atop already marginal fuels should limit fire-weather concerns here. ...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 1132 AM CST Tue Feb 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE SOUTHEAST... ...SUMMARY... Severe storms will be possible Wednesday afternoon into Wednesday night from the Sabine Valley vicinity into far western Georgia. ...Synopsis... A broad trough with multiple embedded mid-level vorticity maxima will become more consolidated with a 125 knot mid-level jet streak over the Lower Ohio River Valley by 12Z Thursday. At the surface, a weak low will move along a frontal zone from West Texas to the Ohio Valley and then deepen into the eastern Great Lakes between 06Z and 12Z Thursday. A broad warm sector will be in place along the Gulf Coast states and will attempt to progress inland, but extensive precipitation within a warm air advection zone from northern Louisiana to northern Georgia will stunt its northward progress. ...Southeast... There is a consistent signal among 12Z CAM guidance for a line of storms to either develop south of or emanate from an expansive area of precipitation across Louisiana tomorrow morning. There will be a period of time during the afternoon when this line of storms may have sufficient instability (amid a strongly sheared environment) to support a damaging wind threat and tornado threat, particularly with any embedded supercells). However, by late afternoon/evening this line of storms will weaken as it moves east of the better instability. An additional severe weather threat will evolve from the late afternoon into the overnight hours as the surface front surges southeast and the low-level jet strengthens. This threat will begin across eastern Louisiana. Earlier in the afternoon, winds will be veered across this region, but as the front sharpens and the low-level jet strengthens, winds are expected to back somewhat which will increase low-level convergence along the front and strengthen low-level shear. The southeastward acceleration of the surface front may eventually outrun the line of storms given the mean storm motion vector, however, 12Z guidance has indicated a greater threat for a pre-frontal band of supercells after 06Z across southern Alabama and the western Florida Panhandle. This scenario seems reasonable given the stronger low-level jet forecast between 06Z and 12Z and also based on current (17Z) surface observations showing dewpoints 2 to 3 F greater than most guidance today. A pre-frontal band of supercells would continue the severe weather threat, including the tornado threat, through the entire overnight period. The slight risk has been expanded south and east to address this concern. ..Bentley.. 02/11/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1041 AM CST Tue Feb 11 2025 Valid 111700Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWESTERN NEW MEXICO AND FAR SOUTHEASTERN ARIZONA... Only minor adjustments were made to today's Elevated and Critical areas. Based on the latest high-resolution data, it appears wind speeds of 25-30 mph will extend slightly further to the northwest near the southern NM/AZ border. This is also where relative humidity in the low teens will be present by late this afternoon. Otherwise, please see the previous forecast discussion for additional meteorological details. ..Barnes.. 02/11/2025 .PREV DISCUSSION... /ISSUED 0113 AM CST Tue Feb 11 2025/ ...Synopsis... Within the base of a large-scale trough over the West, an embedded shortwave trough and strong deep-layer westerly flow will overspread the Southwest. In response, a surface low will deepen over the Four Corners before drifting east-southeastward across NM. ...Southwest NM and far southeast AZ... South of the surface low, a tightening pressure gradient will yield 25-30 mph sustained west-southwesterly surface winds (with higher gusts) across southwest NM and far southeast AZ. These winds will combine with a warm/dry antecedent air mass (15-20 percent afternoon RH), and given modestly dry/receptive fuels, critical fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Tue Feb 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT FOR PARTS OF SOUTH/SOUTHEAST TX AND MS/AL... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...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. ..Thompson/Moore.. 02/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Tue Feb 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT FOR PARTS OF SOUTH/SOUTHEAST TX AND MS/AL... ...SUMMARY... Isolated strong to severe thunderstorms are possible from south Texas into parts of Mississippi and Alabama through tonight. ...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. ..Thompson/Moore.. 02/11/2025 Read more

No Mesoscale Discussions are in effect as of Tue Feb 11 16:33:02 UTC 2025.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Tue Feb 11 2025 Valid 111300Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST TEXAS AND THE LOWER MISSISSIPPI VALLEY INTO SOUTHERN MISSISSIPPI AND CENTRAL ALABAMA.... ...SUMMARY... Isolated to scattered thunderstorms are possible from the southern Plains into the lower Mississippi Valley. Some strong to severe thunderstorms are possible from southeast Texas and the Lower Mississippi Valley into southern Mississippi and central Alabama. ...Synopsis... A pair of shortwave troughs are expected to progress through the southern Plains today as the cyclonic flow aloft across the western CONUS deepens. The first of these shortwaves is currently moving through the southern High Plains while the second remains off the coast of the northern Baja Peninsula. Both of those shortwaves are expected to progress quickly eastward, with the lead wave reaching the Mid-Atlantic by early Wednesday and the second shortwave reaching central TX. ...Lower MS Valley into southern/central MS and AL... As mentioned in the synopsis, the lead shortwave trough is currently moving through the southern High Plains, with preceding warm-air advection contributing to an expansive area of precipitation from the TX Hill Country into the Mid-South. General expectation is that this area of precipitation will gradually shift northeastward throughout the day, remaining just ahead of the eastward-progressing shortwave. Low-level moisture return ahead of the first wave will be modest, particularly across TX where the modified Gulf moisture will likely remain confined to the coastal plain. Farther east, greater inland moisture advection is anticipated, with mid 60s dewpoints advection through much of the Lower MS Valley by the early afternoon. Lower 60s dewpoints are likely in the central portions of MS and AL by the late afternoon/early evening. Even with this low-level moisture advection, mid-level temperatures will remain warm, keeping the overall buoyancy modest (i.e. MUCAPE less than 1000 J/kg) across the region. In contrast to the modest buoyancy, vertical shear will be quite strong, with effective bulk shear over 50 kt from the Lower MS Valley into AL and MS during the afternoon and evening. This strong vertical shear may be able to compensate for the lower buoyancy, and there could be a window for a few strong to severe storms this afternoon/evening along and ahead of the cold front from southern MS into southern and central AL. Primary risk would be damaging wind gusts, but enough low-level shear exists for a low-probability tornado threat as well. ...Southern Plains late tonight... Strong large-scale forcing for ascent will spread across the southern High Plains and into west TX late tonight ahead of the second shortwave trough mentioned in the synopsis. Notable moistening between 850 and 700 mb combined with mid-level cooling will help support modest elevated buoyancy. Thunderstorms are expected to develop across West TX tonight before then spreading eastward/northeastward into more of OK and north/central TX. Much of this activity will be displaced well north/northwest of front and greater low-level moisture. Some hail is possible, but updraft depth and duration will be limited by weak buoyancy, and the current expectation is for any hail to remain very isolated. As these storms move east/southeast with time, some interaction could occur with a warm front gradually moving northward into more of southeast TX early Wednesday morning. Increased buoyancy as well as enhanced mesoscale ascent in the vicinity of the front is expected to result in greater thunderstorm depth and duration. Vertical shear will remain strong as well, with all of these factors supporting a greater severe potential across southeast TX and adjacent far southwestern LA early Wednesday morning. Damaging gusts and/or a brief tornado are the primary threats. ..Mosier/Broyles.. 02/11/2025 Read more

MD 0080 CONCERNING HEAVY SNOW FOR CENTRAL AND EASTERN KENTUCKY/WESTERN VIRGINIA/SOUTHERN WEST VIRGINIA
Mesoscale Discussion 0080 NWS Storm Prediction Center Norman OK 0306 AM CST Tue Feb 11 2025 Areas affected...Central and Eastern Kentucky/Western Virginia/Southern West Virginia Concerning...Heavy snow Valid 110906Z - 111500Z SUMMARY...A band of snow will continue to develop across the Ohio Valley and central Appalachians over the next couple of hours. Snowfall rates of greater than one inch per hour will be possible within the heavier parts of the band, with a mix of freezing rain and snow to the south of this band. DISCUSSION...Water vapor imagery shows west-southwesterly mid-level flow currently present across the eastern U.S., with a split mid-level jet pattern evident. Lift is likely being enhanced within the right entrance region of a mid-level jet that is analyzed in northern Kentucky. Widespread precipitation, in the form of a mix of rain, freezing rain and snow, is ongoing to the south of this feature from southeast Missouri eastward across Kentucky into western Virginia. Isentropic lift, in conjunction with strengthening low-level flow, is forecast to steadily increase along this east-to-west corridor early this morning. Surface temperatures are in the mid 30s F across much of central Kentucky, with lower 30s F in the central Appalachians. Temperatures will continue to gradually cool as the coverage of moderate to heavy precipitation increases early this morning. Within the more intense parts of the band, pockets of heavy snowfall are expected, with some locations exceeding one inch per hour. To the south of this band of snow, precipitation is expected to be a freezing rain and snow mix. After daybreak, warmer air is forecast to spread northward into parts of central and eastern Kentucky, which result in a changeover to rain in many areas. ..Broyles/Mosier.. 02/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RNK...RLX...MRX...JKL...ILN...LMK... LAT...LON 37228568 37328600 37428621 37508627 37668629 37858619 38018601 38168573 38318519 38508428 38578299 38588149 38488059 38318008 37977965 37467963 37197977 37047998 36898037 36788127 36858262 37048453 37228568 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0338 AM CST Tue Feb 11 2025 Valid 141200Z - 191200Z ...DISCUSSION... ...Day 4/Friday... Late in the period, the approaching trough will promote moisture return within the Lower Mississippi Valley, Arkansas, and East Texas. Model guidance shows some hints at potential storm development, but coverage is far from certain due to some lingering capping from warmer air aloft. Should storms form, they most likely would be elevated. Coverage concerns preclude adding severe probabilities, but large hail is conditionally possible. ...Day 5/Saturday... A strong trough, which has trended more amplified in the ECMWF, is expected to impact the Sabine Valley into the Southeast starting in the afternoon. The latest model trends also have a more favorable placement of the surface low in the Tennessee Valley. These factors will drive strong moisture advection into the region by Saturday morning, continuing into Sunday. Intense wind fields throughout the column will support organized storms capable of all hazards. Damaging winds, particularly with linear convection along the strong cold front, currently appears as the main threat. The magnitude of the tornado threat will largely depend on discrete development ahead of the front. Given the moist environment with minimal inhibition and strong forcing, that scenario is certainly plausible. Discrete development or not, low-level wind fields still will support line-embedded circulations. Despite more limited buoyancy farther north, the strongly forced convective line and 60-70 kts of 850 mb flow would support damaging winds even in shallow convection. Uncertainties still remain along the fringes of the highlighted area (i.e., how far west will convection form, how unstable will it be to the north/east). Mid-level lapse rates will also not be overlay steep. Even so, the overall pattern continues to support the potential for scattered to numerous severe storms. ...Day 6/Sunday... As the strong trough and cold front continue east, the convective line will likely stretch from the eastern Florida Panhandle into the Piedmont early Sunday morning. Strong forcing and wind fields will still be in place. The primary uncertainty is the degree of destabilization that can occur ahead of the line given the arrival before the diurnal heating maximum. Where heating can occur, which may be near the coastline, some severe potential will exist. The intensity and coverage of these storms is enough in question that severe probabilities will be withheld. ...Day 7 Onward... Severe potential should be minimal on Monday given the expansive colder air and surface high pressure. Another shortwave trough will approach the southern Plains on Tuesday. While some moisture return is possible, this will occur after a fairly substantial cold air intrusion to the central Gulf. Uncertainty in an appreciable severe risk is high. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0214 AM 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 Piedmont. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... Thunderstorms will be ongoing early Thursday along a cold front in the Florida Panhandle into southwest Georgia. With forcing for ascent rapidly lifting northeastward away from the region, the overall severe threat with this activity appears low. An isolated strong gust could occur into mid-morning, however. Farther north in the southern Appalachians and adjacent Piedmont, strong forcing could promote a few thunderstorms early in the period. As this activity moves eastward, it should encounter a cold air wedge east of the terrain. Northward advection of moisture is not likely to occur sufficiently to support much in the way of instability or strong surface gusts during the afternoon. A strong upper trough will move into northern/central California late Thursday into Friday morning. As a frontal system impacts the region, strong forcing and cold air aloft are expected to support lift/buoyancy that will be marginally supportive of lightning activity. Some of this activity could extend inland into parts of the Sacramento Valley. ..Wendt.. 02/11/2025 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0214 AM 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 Piedmont. Additional thunderstorms may occur in coastal central California and parts of the Sacramento Valley. Severe weather potential currently appears low. ...Synopsis... Thunderstorms will be ongoing early Thursday along a cold front in the Florida Panhandle into southwest Georgia. With forcing for ascent rapidly lifting northeastward away from the region, the overall severe threat with this activity appears low. An isolated strong gust could occur into mid-morning, however. Farther north in the southern Appalachians and adjacent Piedmont, strong forcing could promote a few thunderstorms early in the period. As this activity moves eastward, it should encounter a cold air wedge east of the terrain. Northward advection of moisture is not likely to occur sufficiently to support much in the way of instability or strong surface gusts during the afternoon. A strong upper trough will move into northern/central California late Thursday into Friday morning. As a frontal system impacts the region, strong forcing and cold air aloft are expected to support lift/buoyancy that will be marginally supportive of lightning activity. Some of this activity could extend inland into parts of the Sacramento Valley. ..Wendt.. 02/11/2025 Read more