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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CDT Sat Apr 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of the Gulf Coast and Southeast, but severe thunderstorm potential is expected to be low. ...Southeast GA into north FL... A surface cold front will be located near the South Carolina coast southwest to western FL Panhandle and northern Gulf of Mexico at 12z. A moist airmass will exist ahead of the front across northern FL and southeast GA. Modest destabilization, with MLCAPE to 1000 J/kg is forecast. Forecast soundings indicate capping will limit thunderstorm activity except very near the southeastward-advancing cold front. Isolated thunderstorms will be possible by early afternoon. A couple of strong storms with gusty winds are possible, and possibly hail. However, overall severe potential appears limited. ..Leitman/Weinman.. 04/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CDT Sat Apr 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of the Gulf Coast and Southeast, but severe thunderstorm potential is expected to be low. ...Southeast GA into north FL... A surface cold front will be located near the South Carolina coast southwest to western FL Panhandle and northern Gulf of Mexico at 12z. A moist airmass will exist ahead of the front across northern FL and southeast GA. Modest destabilization, with MLCAPE to 1000 J/kg is forecast. Forecast soundings indicate capping will limit thunderstorm activity except very near the southeastward-advancing cold front. Isolated thunderstorms will be possible by early afternoon. A couple of strong storms with gusty winds are possible, and possibly hail. However, overall severe potential appears limited. ..Leitman/Weinman.. 04/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CDT Sat Apr 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of the Gulf Coast and Southeast, but severe thunderstorm potential is expected to be low. ...Southeast GA into north FL... A surface cold front will be located near the South Carolina coast southwest to western FL Panhandle and northern Gulf of Mexico at 12z. A moist airmass will exist ahead of the front across northern FL and southeast GA. Modest destabilization, with MLCAPE to 1000 J/kg is forecast. Forecast soundings indicate capping will limit thunderstorm activity except very near the southeastward-advancing cold front. Isolated thunderstorms will be possible by early afternoon. A couple of strong storms with gusty winds are possible, and possibly hail. However, overall severe potential appears limited. ..Leitman/Weinman.. 04/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CDT Sat Apr 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of the Gulf Coast and Southeast, but severe thunderstorm potential is expected to be low. ...Southeast GA into north FL... A surface cold front will be located near the South Carolina coast southwest to western FL Panhandle and northern Gulf of Mexico at 12z. A moist airmass will exist ahead of the front across northern FL and southeast GA. Modest destabilization, with MLCAPE to 1000 J/kg is forecast. Forecast soundings indicate capping will limit thunderstorm activity except very near the southeastward-advancing cold front. Isolated thunderstorms will be possible by early afternoon. A couple of strong storms with gusty winds are possible, and possibly hail. However, overall severe potential appears limited. ..Leitman/Weinman.. 04/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CDT Sat Apr 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of the Gulf Coast and Southeast, but severe thunderstorm potential is expected to be low. ...Southeast GA into north FL... A surface cold front will be located near the South Carolina coast southwest to western FL Panhandle and northern Gulf of Mexico at 12z. A moist airmass will exist ahead of the front across northern FL and southeast GA. Modest destabilization, with MLCAPE to 1000 J/kg is forecast. Forecast soundings indicate capping will limit thunderstorm activity except very near the southeastward-advancing cold front. Isolated thunderstorms will be possible by early afternoon. A couple of strong storms with gusty winds are possible, and possibly hail. However, overall severe potential appears limited. ..Leitman/Weinman.. 04/21/2024 Read more

MD 0502 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTH-CENTRAL INTO DEEP SOUTH TX
Mesoscale Discussion 0502 NWS Storm Prediction Center Norman OK 0746 PM CDT Sat Apr 20 2024 Areas affected...South-central into deep south TX Concerning...Severe potential...Watch possible Valid 210046Z - 210215Z Probability of Watch Issuance...40 percent SUMMARY...Isolated severe storms may evolve with time this evening, with a threat of large hail and localized severe gusts. DISCUSSION...Elevated convection has recently increased in coverage and intensity north of a cold front across western portions of south-central TX, with recent initiation noted farther south near a stationary front, north of Laredo. Confidence in greater storm coverage this evening is higher with northward extent, where elevated convection may continue to evolve within an environment characterized by MUCAPE of 1000-1500 J/kg (as noted in the 00Z DRT sounding) and sufficient effective shear for some storm organization. Isolated hail will be possible within this regime as storms spread eastward with time. Near-term storm potential farther south remains more uncertain, with generally nebulous large-scale ascent across the region, and some nocturnal cooling/stabilization expected with time. However, the environment south of the deeper post-frontal cold air is conditionally favorable for severe storms, with steep midlevel lapse rates atop rich low-level moisture supporting MLCAPE in excess of 2000 J/kg. If a supercell can evolve within this regime, there would be at least an isolated threat of large to very large hail (approaching 2 inches in diameter), along with some threat for severe gusts with convection that remains rooted closer to the surface. Watch issuance is possible, if supercell development within this more favorable environment appears imminent. ..Dean/Guyer.. 04/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CRP...EWX...BRO... LAT...LON 28050022 28520043 29779985 29769811 28009808 27019871 26799929 27129981 28050022 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0806 PM CDT Sat Apr 20 2024 Valid 210100Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTH TEXAS... ...SUMMARY... Isolated strong to severe storms capable of strong gusts and hail will be possible mainly the remainder of this evening into tonight across portions of central and south Texas. ...Central/Southern TX... Severe probabilities have been trimmed across parts of central TX based on current radar trends and evolution of the rain-cooled airmass. However, a small Slight (level 2 of 5) risk has been added across parts of south TX near/just ahead of the surface front draped west to east from Webb County toward the coast. Convergence along this boundary is noted and several cells have begun to develop over the past 30-60 minutes. Modified 00z DRT RAOB, along with the 00z CRP RAOB and 23z RAP forecast soundings show an environment favorable for large hail and strong thunderstorm gusts. An airmass characterized by large instability through a deep layer, elongated hodographs, and sufficient effective shear, should support at couple of storms capable of large hail and damaging gusts. Furthermore, cells moving east/southeast across northeast Mexico may approach/cross the Rio Grande over the next few hours, also posing some severe risk. ...Mississippi to the Carolinas... A couple of strong storms may persist another few hours (through midnight local time) from southern MS to GA. Locally gusty winds and small hail may occur with the strongest cells. Across the Carolinas, overall severe potential should come to an end once a severe storm near the SC/NC coastal border vicinity moves offshore. Given the diminishing threat, the Marginal (level 1 of 5) risk has been removed with the 01z update. ..Leitman.. 04/21/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0806 PM CDT Sat Apr 20 2024 Valid 210100Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTH TEXAS... ...SUMMARY... Isolated strong to severe storms capable of strong gusts and hail will be possible mainly the remainder of this evening into tonight across portions of central and south Texas. ...Central/Southern TX... Severe probabilities have been trimmed across parts of central TX based on current radar trends and evolution of the rain-cooled airmass. However, a small Slight (level 2 of 5) risk has been added across parts of south TX near/just ahead of the surface front draped west to east from Webb County toward the coast. Convergence along this boundary is noted and several cells have begun to develop over the past 30-60 minutes. Modified 00z DRT RAOB, along with the 00z CRP RAOB and 23z RAP forecast soundings show an environment favorable for large hail and strong thunderstorm gusts. An airmass characterized by large instability through a deep layer, elongated hodographs, and sufficient effective shear, should support at couple of storms capable of large hail and damaging gusts. Furthermore, cells moving east/southeast across northeast Mexico may approach/cross the Rio Grande over the next few hours, also posing some severe risk. ...Mississippi to the Carolinas... A couple of strong storms may persist another few hours (through midnight local time) from southern MS to GA. Locally gusty winds and small hail may occur with the strongest cells. Across the Carolinas, overall severe potential should come to an end once a severe storm near the SC/NC coastal border vicinity moves offshore. Given the diminishing threat, the Marginal (level 1 of 5) risk has been removed with the 01z update. ..Leitman.. 04/21/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0806 PM CDT Sat Apr 20 2024 Valid 210100Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTH TEXAS... ...SUMMARY... Isolated strong to severe storms capable of strong gusts and hail will be possible mainly the remainder of this evening into tonight across portions of central and south Texas. ...Central/Southern TX... Severe probabilities have been trimmed across parts of central TX based on current radar trends and evolution of the rain-cooled airmass. However, a small Slight (level 2 of 5) risk has been added across parts of south TX near/just ahead of the surface front draped west to east from Webb County toward the coast. Convergence along this boundary is noted and several cells have begun to develop over the past 30-60 minutes. Modified 00z DRT RAOB, along with the 00z CRP RAOB and 23z RAP forecast soundings show an environment favorable for large hail and strong thunderstorm gusts. An airmass characterized by large instability through a deep layer, elongated hodographs, and sufficient effective shear, should support at couple of storms capable of large hail and damaging gusts. Furthermore, cells moving east/southeast across northeast Mexico may approach/cross the Rio Grande over the next few hours, also posing some severe risk. ...Mississippi to the Carolinas... A couple of strong storms may persist another few hours (through midnight local time) from southern MS to GA. Locally gusty winds and small hail may occur with the strongest cells. Across the Carolinas, overall severe potential should come to an end once a severe storm near the SC/NC coastal border vicinity moves offshore. Given the diminishing threat, the Marginal (level 1 of 5) risk has been removed with the 01z update. ..Leitman.. 04/21/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0806 PM CDT Sat Apr 20 2024 Valid 210100Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTH TEXAS... ...SUMMARY... Isolated strong to severe storms capable of strong gusts and hail will be possible mainly the remainder of this evening into tonight across portions of central and south Texas. ...Central/Southern TX... Severe probabilities have been trimmed across parts of central TX based on current radar trends and evolution of the rain-cooled airmass. However, a small Slight (level 2 of 5) risk has been added across parts of south TX near/just ahead of the surface front draped west to east from Webb County toward the coast. Convergence along this boundary is noted and several cells have begun to develop over the past 30-60 minutes. Modified 00z DRT RAOB, along with the 00z CRP RAOB and 23z RAP forecast soundings show an environment favorable for large hail and strong thunderstorm gusts. An airmass characterized by large instability through a deep layer, elongated hodographs, and sufficient effective shear, should support at couple of storms capable of large hail and damaging gusts. Furthermore, cells moving east/southeast across northeast Mexico may approach/cross the Rio Grande over the next few hours, also posing some severe risk. ...Mississippi to the Carolinas... A couple of strong storms may persist another few hours (through midnight local time) from southern MS to GA. Locally gusty winds and small hail may occur with the strongest cells. Across the Carolinas, overall severe potential should come to an end once a severe storm near the SC/NC coastal border vicinity moves offshore. Given the diminishing threat, the Marginal (level 1 of 5) risk has been removed with the 01z update. ..Leitman.. 04/21/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0806 PM CDT Sat Apr 20 2024 Valid 210100Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTH TEXAS... ...SUMMARY... Isolated strong to severe storms capable of strong gusts and hail will be possible mainly the remainder of this evening into tonight across portions of central and south Texas. ...Central/Southern TX... Severe probabilities have been trimmed across parts of central TX based on current radar trends and evolution of the rain-cooled airmass. However, a small Slight (level 2 of 5) risk has been added across parts of south TX near/just ahead of the surface front draped west to east from Webb County toward the coast. Convergence along this boundary is noted and several cells have begun to develop over the past 30-60 minutes. Modified 00z DRT RAOB, along with the 00z CRP RAOB and 23z RAP forecast soundings show an environment favorable for large hail and strong thunderstorm gusts. An airmass characterized by large instability through a deep layer, elongated hodographs, and sufficient effective shear, should support at couple of storms capable of large hail and damaging gusts. Furthermore, cells moving east/southeast across northeast Mexico may approach/cross the Rio Grande over the next few hours, also posing some severe risk. ...Mississippi to the Carolinas... A couple of strong storms may persist another few hours (through midnight local time) from southern MS to GA. Locally gusty winds and small hail may occur with the strongest cells. Across the Carolinas, overall severe potential should come to an end once a severe storm near the SC/NC coastal border vicinity moves offshore. Given the diminishing threat, the Marginal (level 1 of 5) risk has been removed with the 01z update. ..Leitman.. 04/21/2024 Read more

WW 0131 Status Updates
STATUS REPORT ON WW 131 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SSE CRE TO 20 NW FLO TO 35 SSW SOP TO 55 SSE EWN. ..WEINMAN..04/21/24 ATTN...WFO...RAH...MHX...ILM...CAE... STATUS REPORT FOR WS 131 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC017-019-047-129-141-155-210140- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BLADEN BRUNSWICK COLUMBUS NEW HANOVER PENDER ROBESON SCC033-043-051-067-069-210140- SC . SOUTH CAROLINA COUNTIES INCLUDED ARE DILLON GEORGETOWN HORRY MARION MARLBORO AMZ250-252-254-256-210140- CW . ADJACENT COASTAL WATERS INCLUDED ARE COASTAL WATERS FROM SURF CITY TO CAPE FEAR NC OUT 20 NM Read more

WW 0131 Status Updates
STATUS REPORT ON WW 131 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SSE CRE TO 20 NW FLO TO 35 SSW SOP TO 55 SSE EWN. ..WEINMAN..04/21/24 ATTN...WFO...RAH...MHX...ILM...CAE... STATUS REPORT FOR WS 131 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC017-019-047-129-141-155-210140- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BLADEN BRUNSWICK COLUMBUS NEW HANOVER PENDER ROBESON SCC033-043-051-067-069-210140- SC . SOUTH CAROLINA COUNTIES INCLUDED ARE DILLON GEORGETOWN HORRY MARION MARLBORO AMZ250-252-254-256-210140- CW . ADJACENT COASTAL WATERS INCLUDED ARE COASTAL WATERS FROM SURF CITY TO CAPE FEAR NC OUT 20 NM Read more

WW 131 SEVERE TSTM NC SC CW 202105Z - 210200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 131 NWS Storm Prediction Center Norman OK 505 PM EDT Sat Apr 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of parts of southern and eastern North Carolina part of eastern South Carolina Coastal Waters * Effective this Saturday afternoon and evening from 505 PM until 1000 PM EDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Widely scattered to scattered strong/severe thunderstorms are forecast to continue spreading east-southeastward across portions of the Carolinas this afternoon. Large hail, and locally damaging wind gusts, can be expected with the most intense storms, before moving offshore this evening. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 35 miles north of New Bern NC to 35 miles west of Myrtle Beach SC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29040. ...Goss Read more

MD 0501 CONCERNING SEVERE THUNDERSTORM WATCH 131... FOR PORTIONS OF SOUTHEASTERN NC AND NORTHEASTERN SC
Mesoscale Discussion 0501 NWS Storm Prediction Center Norman OK 0600 PM CDT Sat Apr 20 2024 Areas affected...Portions of southeastern NC and northeastern SC Concerning...Severe Thunderstorm Watch 131... Valid 202300Z - 210030Z The severe weather threat for Severe Thunderstorm Watch 131 continues. SUMMARY...The severe risk will continue across Severe Thunderstorm Watch 131 for the next few hours. Primary concerns are isolated large hail and locally damaging gusts. DISCUSSION...Two main corridors of severe storms persist across portions of southeastern NC and northeastern SC this evening. Closer to the southeastern NC coast, recent storm mergers have yielded a consolidated supercell which is generally anchored to an outflow-modified sea breeze boundary. This storm will likely continue drifting slowly south-southeastward to the coast, with a risk of locally damaging gusts (50-65 mph) and isolated large hail (up to 1.5 inches in diameter). Slightly farther northwest (over the northeastern SC/southeastern NC border), splitting storms with occasional supercell structure are ongoing amid a long/straight hodograph environment and moderate surface-based instability. These storms will continue to pose a risk of isolated large hail as well, in addition to severe gusts given a steep low-level lapse rate plume extending toward the inflow of this activity. The severe threat will generally persist until storms move off the coast in the next 3-4 hours. ..Weinman.. 04/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MHX...RAH...ILM...CAE... LAT...LON 33557845 33697931 33998009 34318045 34568046 34938005 35077928 35027839 34737755 34347724 33997752 33557845 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0314 PM CDT Sat Apr 20 2024 Valid 221200Z - 281200Z Multiple mid-level troughs will amplify across the eastern U.S. as an upper-level ridge builds over the Plains states through the middle of the week. Strong northwesterly downslope flow across the northern High Plains may support at least locally Elevated fire weather conditions Day 3/Monday afternoon. Thereafter, medium-range guidance agrees that a series of mid-level troughs will eject into the Plains states Days 6-8 (Thursday-Saturday), supporting multiple instances of surface-cyclone development and the eastward progression of a dryline. For each day Thursday-Saturday, critically dry and windy conditions are expected behind the dryline over the southern High Plains. 70 percent Critical probabilities have been introduced where guidance consensus and consistency is greatest in depicting overlapping favorable winds/RH to support significant wildfire-spread potential. ..Squitieri.. 04/20/2024 ...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 0314 PM CDT Sat Apr 20 2024 Valid 221200Z - 281200Z Multiple mid-level troughs will amplify across the eastern U.S. as an upper-level ridge builds over the Plains states through the middle of the week. Strong northwesterly downslope flow across the northern High Plains may support at least locally Elevated fire weather conditions Day 3/Monday afternoon. Thereafter, medium-range guidance agrees that a series of mid-level troughs will eject into the Plains states Days 6-8 (Thursday-Saturday), supporting multiple instances of surface-cyclone development and the eastward progression of a dryline. For each day Thursday-Saturday, critically dry and windy conditions are expected behind the dryline over the southern High Plains. 70 percent Critical probabilities have been introduced where guidance consensus and consistency is greatest in depicting overlapping favorable winds/RH to support significant wildfire-spread potential. ..Squitieri.. 04/20/2024 ...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 0314 PM CDT Sat Apr 20 2024 Valid 221200Z - 281200Z Multiple mid-level troughs will amplify across the eastern U.S. as an upper-level ridge builds over the Plains states through the middle of the week. Strong northwesterly downslope flow across the northern High Plains may support at least locally Elevated fire weather conditions Day 3/Monday afternoon. Thereafter, medium-range guidance agrees that a series of mid-level troughs will eject into the Plains states Days 6-8 (Thursday-Saturday), supporting multiple instances of surface-cyclone development and the eastward progression of a dryline. For each day Thursday-Saturday, critically dry and windy conditions are expected behind the dryline over the southern High Plains. 70 percent Critical probabilities have been introduced where guidance consensus and consistency is greatest in depicting overlapping favorable winds/RH to support significant wildfire-spread potential. ..Squitieri.. 04/20/2024 ...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 0314 PM CDT Sat Apr 20 2024 Valid 221200Z - 281200Z Multiple mid-level troughs will amplify across the eastern U.S. as an upper-level ridge builds over the Plains states through the middle of the week. Strong northwesterly downslope flow across the northern High Plains may support at least locally Elevated fire weather conditions Day 3/Monday afternoon. Thereafter, medium-range guidance agrees that a series of mid-level troughs will eject into the Plains states Days 6-8 (Thursday-Saturday), supporting multiple instances of surface-cyclone development and the eastward progression of a dryline. For each day Thursday-Saturday, critically dry and windy conditions are expected behind the dryline over the southern High Plains. 70 percent Critical probabilities have been introduced where guidance consensus and consistency is greatest in depicting overlapping favorable winds/RH to support significant wildfire-spread potential. ..Squitieri.. 04/20/2024 ...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 0250 PM CDT Sat Apr 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHEAST...AND INTO CENTRAL AND SOUTHERN TEXAS... ...SUMMARY... Marginally severe storms capable of strong wind gusts and hail will be possible mainly this afternoon/evening across portions of central and south Texas, and from southern Mississippi to southern North Carolina. No changed required for the 20Z update. For more information see mesoscale discussion 498, 499, 500. ..Jewell.. 04/20/2024 .PREV DISCUSSION... /ISSUED 1112 AM CDT Sat Apr 20 2024/ ...Synopsis... Mid-morning radar mosaics show a broad swath of elevated convection ongoing across the southern Plains ahead of an approaching upper-level wave. While a few instances of gusty winds and/or sub-severe hail will be possible with this activity, a slightly more robust severe threat will be focused along a surface cold front recently analyzed from the southern Appalachians to southern TX. Surface high pressure is expected to build east into the Plains/MS Valley through the day, which will nudge the cold front slowly southward over the next 24 hours. Isolated to scattered thunderstorms are expected to develop along this boundary by mid-afternoon with a few strong/severe storms possible. ...Southern Gulf states to the Southeast... Mostly clear to partly cloud skies are noted along and ahead of the cold front from SC into southern AL/MS. Diurnal warming of a modestly moist air mass should yield MLCAPE values upwards of 1000 J/kg by early to mid-afternoon. Despite minimal inhibition, weak forcing for ascent along the front should support isolated to widely scattered thunderstorms. Storm motions largely along the boundary should support initial cells growing upscale into clusters through the afternoon/evening. While low to mid-level winds are modest, 30-40 knot flow aloft may support sufficient deep-layer shear for a few more organized cells/clusters with an attendant hail risk. Damaging outflow gusts are also possible - especially across areas where surface temperatures can warm into the mid/upper 80s by peak heating. Based on 16 UTC observations, this appears most likely to occur across parts of GA into the Carolinas. ...Southern Texas... Two clusters of thunderstorms appear possible this afternoon and evening across southern Texas. Elevated convection developing along the western fringe of the synoptic front across the Big Bend region of TX should gradually become surface-based as storms migrate east into an increasingly buoyant air mass. Thunderstorms should also be focused along a more subtle boundary noted along the TX Coastal Plain in recent surface analyses. Across both regions, sufficient deep-layer shear should be in place to support a few organized cells, but mean storm motions and deep-layer shear vectors largely along the initiating boundaries should favor convective clusters with an attendant hail/wind risk. A low-end tornado threat may materialize along the boundary along the Coastal Plain where low-level flow should remain backed to the south/southeast, yielding effective SRH values between 100-150 m2/s2. However, given the potential for upscale growth, this threat is expected to be fairly limited. Read more