Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 AM CDT Wed Mar 12 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EASTERN MISSISSIPPI INTO ALABAMA...WESTERN GEORGIA...AND THE FLORIDA PANHANDLE... ...SUMMARY... A few severe thunderstorms producing hail and locally damaging gusts are possible from eastern Mississippi into Alabama, western Georgia, and parts of the Florida Panhandle on Thursday. ...Synopsis... A shortwave trough will continue eastward across the southeastern states on Thursday, with midlevel speed max traversing the northern Gulf. The trough will be located over AL at midday, with height rises on the back side of the trough across MS and southwest AL during the afternoon. Very cold temperatures aloft will exist with this system, which will contribute to destabilization despite less-than-optimal moisture content. Elsewhere, a large and deep upper trough will progress across the West, with an intense upper vort max and jet streak moving into the southern to central High Plains by Friday morning. Thunderstorms are unlikely through Friday morning with this system. ...Eastern MS...AL...Western GA...FL Panhandle... Areas of early day thunderstorms appear likely over northern MS, beneath the upper low. Hail will be possible given such cold temperatures aloft. Farther south, uncertainty is high for any leftover convection or outflows coming in from the west. If a more robust convective system can persist overnight across AR, then isolated damaging gusts could occur. Later in the day, heating will steepen low-level lapse rates into AL, GA and FL. However, the trough will continue moving rather quickly, which may tend to shunt the more favorable ascent eastward with time. A small area of favorable lift and destabilization may develop over southeast AL, southwest GA, and the FL Panhandle, with large hail possible given long hodographs and cool air aloft. ..Jewell.. 03/12/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 AM CDT Wed Mar 12 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EASTERN MISSISSIPPI INTO ALABAMA...WESTERN GEORGIA...AND THE FLORIDA PANHANDLE... ...SUMMARY... A few severe thunderstorms producing hail and locally damaging gusts are possible from eastern Mississippi into Alabama, western Georgia, and parts of the Florida Panhandle on Thursday. ...Synopsis... A shortwave trough will continue eastward across the southeastern states on Thursday, with midlevel speed max traversing the northern Gulf. The trough will be located over AL at midday, with height rises on the back side of the trough across MS and southwest AL during the afternoon. Very cold temperatures aloft will exist with this system, which will contribute to destabilization despite less-than-optimal moisture content. Elsewhere, a large and deep upper trough will progress across the West, with an intense upper vort max and jet streak moving into the southern to central High Plains by Friday morning. Thunderstorms are unlikely through Friday morning with this system. ...Eastern MS...AL...Western GA...FL Panhandle... Areas of early day thunderstorms appear likely over northern MS, beneath the upper low. Hail will be possible given such cold temperatures aloft. Farther south, uncertainty is high for any leftover convection or outflows coming in from the west. If a more robust convective system can persist overnight across AR, then isolated damaging gusts could occur. Later in the day, heating will steepen low-level lapse rates into AL, GA and FL. However, the trough will continue moving rather quickly, which may tend to shunt the more favorable ascent eastward with time. A small area of favorable lift and destabilization may develop over southeast AL, southwest GA, and the FL Panhandle, with large hail possible given long hodographs and cool air aloft. ..Jewell.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Mar 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms will be possible from parts of north Texas and southeast Oklahoma into the ArkLaTex late this afternoon and evening. Large to very large hail and severe gusts should be the primary hazards. ...North Texas/Southeast Oklahoma into the Lower Mississippi Valley... A shortwave trough with an attendant 70-90+ kt west-southwesterly mid-level jet will advance eastward across the southern Plains today. A related surface low should gradually consolidate over OK and likewise develop slowly eastward through the period. Shallow low-level moisture will continue to stream northward ahead of a dryline that will mix eastward across parts of central TX through late this afternoon, with surface dewpoints generally remaining in the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD sounding will be slow to erode, and this will likely inhibit robust thunderstorms from developing until at least late afternoon (21Z or later). Even so, mid-level temperatures will cool through the day as the shortwave trough approaches, and steep lapse rates aloft in combination with daytime heating will also aid in the development of around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK ahead of the dryline. While low-level winds are expected to remain fairly modest, strengthening mid-level winds and related deep-layer shear should support organized convection. While there is still some uncertainty regarding how warm/moist the boundary layer will become through heating, it seems likely that attempts at robust convective initiation will occur by late afternoon/early evening across north-central TX into southeast OK as convergence increases along/near the dryline. Any convection that can develop and persist will likely become supercellular and pose a threat for large to very large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale growth may occur with this activity through the evening across parts of the ArkLaTex, with some risk for damaging winds with any sustained cluster continuing eastward over the lower MS Valley overnight. The tornado threat remains less clear, with modest/shallow low-level moisture and generally weak low-level winds potentially limiting factors. Still, a chance for a tornado or two may exist with any sustained supercell this evening as a southwesterly low-level jet gradually strengthens, especially in the ArkLaTex region. ...Coastal Southern California... Short-term guidance shows a low-topped band of convection will move across parts of coastal southern CA in advance of an approaching mid-level trough over the eastern Pacific. While a strong gust cannot be ruled out with this activity, the overall thermodynamic environment appears too limited for low severe probabilities. ..Gleason/Flournoy.. 03/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Wed Mar 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms are possible from north Texas and southeast Oklahoma into the Ark-La-Tex late this afternoon and evening. Large to very large hail and severe gusts are the primary hazards. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level shortwave trough over NM/Chihuahua quickly moving eastward into Far West and Southwest TX. This disturbance will reach the lower MS Valley and central Gulf Coast by early Thursday morning. A belt of strong west-southwesterly 500-mb flow will move through the base of the trough over TX into the lower MS Valley during the period. In response, a surface low will develop across western Texas and Oklahoma with increasing southerly flow and moisture return across Texas into Oklahoma and into the lower Mississippi Valley ahead of the dryline/front. ...Parts of TX/OK eastward into the Lower MS Valley... Surface analysis shows a plume of northward-moving moisture from a modifying Gulf airmass across TX near and to the east of I-35 this morning. An initially strong cap (reference 12 UTC Fort Worth, TX raob) will inhibit storm development through the mid afternoon as southerly low-level moisture continues to stream northward into northeast TX and eastern OK/western AR. Moderate instability is forecast by mid-late afternoon due in part to cold-air advection in the mid-levels associated with the approaching trough. Upwards of 1000-1500 J/kg MLCAPE is forecast east of the dryline. Strong heating will likely lead to surface dewpoints mixing into the mid-upper 50s over north and northeast TX. Model guidance indicates scattered storms will likely develop once the cap erodes in parts of eastern OK southward into TX with this activity spreading east into adjacent portions of AR/LA this evening and eventually into the Ark-La-Miss late. Lower coverage of storms is forecast farther south across east-central into parts of east TX. However, stronger deep-layer shear with southward extent will favor supercell modes compared to a mix of strong/severe multicells and supercell structures farther north. Large to very large hail (potentially 2-3 inches in diameter) is possible with the stronger storms. An attendant wind risk will also accompany the stronger storms given the steep lapse rates. Upscale growth into one or two clusters is possible during the evening as this activity moves east into the lower MS Valley. ...Elsewhere... Short-term model guidance indicates a very low-topped forced band will move southeast across parts of the southern CA coast in advance of an approaching eastern Pacific mid-level trough. A strong gust cannot be ruled out with this activity, but the risk appears too marginal for low-severe probabilities. ..Smith/Dean.. 03/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Wed Mar 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms are possible from north Texas and southeast Oklahoma into the Ark-La-Tex late this afternoon and evening. Large to very large hail and severe gusts are the primary hazards. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level shortwave trough over NM/Chihuahua quickly moving eastward into Far West and Southwest TX. This disturbance will reach the lower MS Valley and central Gulf Coast by early Thursday morning. A belt of strong west-southwesterly 500-mb flow will move through the base of the trough over TX into the lower MS Valley during the period. In response, a surface low will develop across western Texas and Oklahoma with increasing southerly flow and moisture return across Texas into Oklahoma and into the lower Mississippi Valley ahead of the dryline/front. ...Parts of TX/OK eastward into the Lower MS Valley... Surface analysis shows a plume of northward-moving moisture from a modifying Gulf airmass across TX near and to the east of I-35 this morning. An initially strong cap (reference 12 UTC Fort Worth, TX raob) will inhibit storm development through the mid afternoon as southerly low-level moisture continues to stream northward into northeast TX and eastern OK/western AR. Moderate instability is forecast by mid-late afternoon due in part to cold-air advection in the mid-levels associated with the approaching trough. Upwards of 1000-1500 J/kg MLCAPE is forecast east of the dryline. Strong heating will likely lead to surface dewpoints mixing into the mid-upper 50s over north and northeast TX. Model guidance indicates scattered storms will likely develop once the cap erodes in parts of eastern OK southward into TX with this activity spreading east into adjacent portions of AR/LA this evening and eventually into the Ark-La-Miss late. Lower coverage of storms is forecast farther south across east-central into parts of east TX. However, stronger deep-layer shear with southward extent will favor supercell modes compared to a mix of strong/severe multicells and supercell structures farther north. Large to very large hail (potentially 2-3 inches in diameter) is possible with the stronger storms. An attendant wind risk will also accompany the stronger storms given the steep lapse rates. Upscale growth into one or two clusters is possible during the evening as this activity moves east into the lower MS Valley. ...Elsewhere... Short-term model guidance indicates a very low-topped forced band will move southeast across parts of the southern CA coast in advance of an approaching eastern Pacific mid-level trough. A strong gust cannot be ruled out with this activity, but the risk appears too marginal for low-severe probabilities. ..Smith/Dean.. 03/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Wed Mar 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms are possible from north Texas and southeast Oklahoma into the Ark-La-Tex late this afternoon and evening. Large to very large hail and severe gusts are the primary hazards. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level shortwave trough over NM/Chihuahua quickly moving eastward into Far West and Southwest TX. This disturbance will reach the lower MS Valley and central Gulf Coast by early Thursday morning. A belt of strong west-southwesterly 500-mb flow will move through the base of the trough over TX into the lower MS Valley during the period. In response, a surface low will develop across western Texas and Oklahoma with increasing southerly flow and moisture return across Texas into Oklahoma and into the lower Mississippi Valley ahead of the dryline/front. ...Parts of TX/OK eastward into the Lower MS Valley... Surface analysis shows a plume of northward-moving moisture from a modifying Gulf airmass across TX near and to the east of I-35 this morning. An initially strong cap (reference 12 UTC Fort Worth, TX raob) will inhibit storm development through the mid afternoon as southerly low-level moisture continues to stream northward into northeast TX and eastern OK/western AR. Moderate instability is forecast by mid-late afternoon due in part to cold-air advection in the mid-levels associated with the approaching trough. Upwards of 1000-1500 J/kg MLCAPE is forecast east of the dryline. Strong heating will likely lead to surface dewpoints mixing into the mid-upper 50s over north and northeast TX. Model guidance indicates scattered storms will likely develop once the cap erodes in parts of eastern OK southward into TX with this activity spreading east into adjacent portions of AR/LA this evening and eventually into the Ark-La-Miss late. Lower coverage of storms is forecast farther south across east-central into parts of east TX. However, stronger deep-layer shear with southward extent will favor supercell modes compared to a mix of strong/severe multicells and supercell structures farther north. Large to very large hail (potentially 2-3 inches in diameter) is possible with the stronger storms. An attendant wind risk will also accompany the stronger storms given the steep lapse rates. Upscale growth into one or two clusters is possible during the evening as this activity moves east into the lower MS Valley. ...Elsewhere... Short-term model guidance indicates a very low-topped forced band will move southeast across parts of the southern CA coast in advance of an approaching eastern Pacific mid-level trough. A strong gust cannot be ruled out with this activity, but the risk appears too marginal for low-severe probabilities. ..Smith/Dean.. 03/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Wed Mar 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms are possible from north Texas and southeast Oklahoma into the Ark-La-Tex late this afternoon and evening. Large to very large hail and severe gusts are the primary hazards. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level shortwave trough over NM/Chihuahua quickly moving eastward into Far West and Southwest TX. This disturbance will reach the lower MS Valley and central Gulf Coast by early Thursday morning. A belt of strong west-southwesterly 500-mb flow will move through the base of the trough over TX into the lower MS Valley during the period. In response, a surface low will develop across western Texas and Oklahoma with increasing southerly flow and moisture return across Texas into Oklahoma and into the lower Mississippi Valley ahead of the dryline/front. ...Parts of TX/OK eastward into the Lower MS Valley... Surface analysis shows a plume of northward-moving moisture from a modifying Gulf airmass across TX near and to the east of I-35 this morning. An initially strong cap (reference 12 UTC Fort Worth, TX raob) will inhibit storm development through the mid afternoon as southerly low-level moisture continues to stream northward into northeast TX and eastern OK/western AR. Moderate instability is forecast by mid-late afternoon due in part to cold-air advection in the mid-levels associated with the approaching trough. Upwards of 1000-1500 J/kg MLCAPE is forecast east of the dryline. Strong heating will likely lead to surface dewpoints mixing into the mid-upper 50s over north and northeast TX. Model guidance indicates scattered storms will likely develop once the cap erodes in parts of eastern OK southward into TX with this activity spreading east into adjacent portions of AR/LA this evening and eventually into the Ark-La-Miss late. Lower coverage of storms is forecast farther south across east-central into parts of east TX. However, stronger deep-layer shear with southward extent will favor supercell modes compared to a mix of strong/severe multicells and supercell structures farther north. Large to very large hail (potentially 2-3 inches in diameter) is possible with the stronger storms. An attendant wind risk will also accompany the stronger storms given the steep lapse rates. Upscale growth into one or two clusters is possible during the evening as this activity moves east into the lower MS Valley. ...Elsewhere... Short-term model guidance indicates a very low-topped forced band will move southeast across parts of the southern CA coast in advance of an approaching eastern Pacific mid-level trough. A strong gust cannot be ruled out with this activity, but the risk appears too marginal for low-severe probabilities. ..Smith/Dean.. 03/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Wed Mar 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA... ...SUMMARY... Scattered severe thunderstorms are possible from north Texas and southeast Oklahoma into the Ark-La-Tex late this afternoon and evening. Large to very large hail and severe gusts are the primary hazards. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level shortwave trough over NM/Chihuahua quickly moving eastward into Far West and Southwest TX. This disturbance will reach the lower MS Valley and central Gulf Coast by early Thursday morning. A belt of strong west-southwesterly 500-mb flow will move through the base of the trough over TX into the lower MS Valley during the period. In response, a surface low will develop across western Texas and Oklahoma with increasing southerly flow and moisture return across Texas into Oklahoma and into the lower Mississippi Valley ahead of the dryline/front. ...Parts of TX/OK eastward into the Lower MS Valley... Surface analysis shows a plume of northward-moving moisture from a modifying Gulf airmass across TX near and to the east of I-35 this morning. An initially strong cap (reference 12 UTC Fort Worth, TX raob) will inhibit storm development through the mid afternoon as southerly low-level moisture continues to stream northward into northeast TX and eastern OK/western AR. Moderate instability is forecast by mid-late afternoon due in part to cold-air advection in the mid-levels associated with the approaching trough. Upwards of 1000-1500 J/kg MLCAPE is forecast east of the dryline. Strong heating will likely lead to surface dewpoints mixing into the mid-upper 50s over north and northeast TX. Model guidance indicates scattered storms will likely develop once the cap erodes in parts of eastern OK southward into TX with this activity spreading east into adjacent portions of AR/LA this evening and eventually into the Ark-La-Miss late. Lower coverage of storms is forecast farther south across east-central into parts of east TX. However, stronger deep-layer shear with southward extent will favor supercell modes compared to a mix of strong/severe multicells and supercell structures farther north. Large to very large hail (potentially 2-3 inches in diameter) is possible with the stronger storms. An attendant wind risk will also accompany the stronger storms given the steep lapse rates. Upscale growth into one or two clusters is possible during the evening as this activity moves east into the lower MS Valley. ...Elsewhere... Short-term model guidance indicates a very low-topped forced band will move southeast across parts of the southern CA coast in advance of an approaching eastern Pacific mid-level trough. A strong gust cannot be ruled out with this activity, but the risk appears too marginal for low-severe probabilities. ..Smith/Dean.. 03/12/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Wed Mar 12 2025 Valid 151200Z - 201200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/SAT... ...DISCUSSION... ...Day 4/Sat - Central Gulf Coast States to the Ohio Valley... A strong large-scale upper trough is forecast to quickly move across the Plains to the MS Valley on Saturday. An intense jet streak will move across the Deep South into the OH Valley as this occurs. At the surface, a low secondary to the 980 mb low over the Upper Midwest is forecast to develop during the late morning/early afternoon across the mid-South. This will aid in further northward transport of rich Gulf moisture into portions of the Lower MS Valley and TN Valleys. Atop this moisture-primed boundary layer, cold 500 mb temperatures are forecast. This may support fairly steep lapse rates, which would foster moderate instability across portions of MS/AL amid supercell wind profiles. However, some uncertainty remains tied to the evolution of convection in the Day 3/Fri period into the morning hours of Saturday. Some forecast guidance suggests a relatively pristine warm sector will be maintained, or if only isolated convection develops overnight/early Saturday, recovery could occur. If this scenario unfolds, a concerning severe weather setup supporting all-hazard severe could unfold across portions of LA/MS/AL through the day and into evening, and eventually spreading east into GA overnight. Trends will be monitored closely over the coming days and further adjustments to the 30 percent/Enhanced risk area may be needed in future outlooks. With northward extent, instability will become more limited. Nevertheless, sufficient moisture amid intense deep-layer flow will support swaths of strong/damaging winds into the Ohio Valley and portions of the central Appalachians Saturday and Saturday night. Higher outlook probabilities may be needed in subsequent outlooks if confidence increases. ...Day 5/Sun - North Florida into the Carolinas and Mid-Atlantic... A strong upper trough will shift east across the Midwest and Southeast on Sunday. Strong deep-layer southwesterly flow ahead of the trough will overspread much of the eastern U.S. atop a moist boundary layer. Bands of convection will likely produce swaths of strong to severe gusts ahead of an eastward-advancing cold front. ...Days 6-8/Mon-Wed... An upper trough will move offshore over the Atlantic on Monday, while a broad upper ridge spreads across the Plains in its wake. Another large-scale upper trough will move across the western U.S. on Tuesday, ejecting across the Plains and into the MS Valley on Wednesday. Some severe potential could return to parts of the central or south-central states toward the end of the period with this system, but current model forecasts suggest moisture return in the wake of the Day 4/5 system will remain poor. Trends will be monitored over the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Wed Mar 12 2025 Valid 151200Z - 201200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/SAT... ...DISCUSSION... ...Day 4/Sat - Central Gulf Coast States to the Ohio Valley... A strong large-scale upper trough is forecast to quickly move across the Plains to the MS Valley on Saturday. An intense jet streak will move across the Deep South into the OH Valley as this occurs. At the surface, a low secondary to the 980 mb low over the Upper Midwest is forecast to develop during the late morning/early afternoon across the mid-South. This will aid in further northward transport of rich Gulf moisture into portions of the Lower MS Valley and TN Valleys. Atop this moisture-primed boundary layer, cold 500 mb temperatures are forecast. This may support fairly steep lapse rates, which would foster moderate instability across portions of MS/AL amid supercell wind profiles. However, some uncertainty remains tied to the evolution of convection in the Day 3/Fri period into the morning hours of Saturday. Some forecast guidance suggests a relatively pristine warm sector will be maintained, or if only isolated convection develops overnight/early Saturday, recovery could occur. If this scenario unfolds, a concerning severe weather setup supporting all-hazard severe could unfold across portions of LA/MS/AL through the day and into evening, and eventually spreading east into GA overnight. Trends will be monitored closely over the coming days and further adjustments to the 30 percent/Enhanced risk area may be needed in future outlooks. With northward extent, instability will become more limited. Nevertheless, sufficient moisture amid intense deep-layer flow will support swaths of strong/damaging winds into the Ohio Valley and portions of the central Appalachians Saturday and Saturday night. Higher outlook probabilities may be needed in subsequent outlooks if confidence increases. ...Day 5/Sun - North Florida into the Carolinas and Mid-Atlantic... A strong upper trough will shift east across the Midwest and Southeast on Sunday. Strong deep-layer southwesterly flow ahead of the trough will overspread much of the eastern U.S. atop a moist boundary layer. Bands of convection will likely produce swaths of strong to severe gusts ahead of an eastward-advancing cold front. ...Days 6-8/Mon-Wed... An upper trough will move offshore over the Atlantic on Monday, while a broad upper ridge spreads across the Plains in its wake. Another large-scale upper trough will move across the western U.S. on Tuesday, ejecting across the Plains and into the MS Valley on Wednesday. Some severe potential could return to parts of the central or south-central states toward the end of the period with this system, but current model forecasts suggest moisture return in the wake of the Day 4/5 system will remain poor. Trends will be monitored over the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Wed Mar 12 2025 Valid 151200Z - 201200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/SAT... ...DISCUSSION... ...Day 4/Sat - Central Gulf Coast States to the Ohio Valley... A strong large-scale upper trough is forecast to quickly move across the Plains to the MS Valley on Saturday. An intense jet streak will move across the Deep South into the OH Valley as this occurs. At the surface, a low secondary to the 980 mb low over the Upper Midwest is forecast to develop during the late morning/early afternoon across the mid-South. This will aid in further northward transport of rich Gulf moisture into portions of the Lower MS Valley and TN Valleys. Atop this moisture-primed boundary layer, cold 500 mb temperatures are forecast. This may support fairly steep lapse rates, which would foster moderate instability across portions of MS/AL amid supercell wind profiles. However, some uncertainty remains tied to the evolution of convection in the Day 3/Fri period into the morning hours of Saturday. Some forecast guidance suggests a relatively pristine warm sector will be maintained, or if only isolated convection develops overnight/early Saturday, recovery could occur. If this scenario unfolds, a concerning severe weather setup supporting all-hazard severe could unfold across portions of LA/MS/AL through the day and into evening, and eventually spreading east into GA overnight. Trends will be monitored closely over the coming days and further adjustments to the 30 percent/Enhanced risk area may be needed in future outlooks. With northward extent, instability will become more limited. Nevertheless, sufficient moisture amid intense deep-layer flow will support swaths of strong/damaging winds into the Ohio Valley and portions of the central Appalachians Saturday and Saturday night. Higher outlook probabilities may be needed in subsequent outlooks if confidence increases. ...Day 5/Sun - North Florida into the Carolinas and Mid-Atlantic... A strong upper trough will shift east across the Midwest and Southeast on Sunday. Strong deep-layer southwesterly flow ahead of the trough will overspread much of the eastern U.S. atop a moist boundary layer. Bands of convection will likely produce swaths of strong to severe gusts ahead of an eastward-advancing cold front. ...Days 6-8/Mon-Wed... An upper trough will move offshore over the Atlantic on Monday, while a broad upper ridge spreads across the Plains in its wake. Another large-scale upper trough will move across the western U.S. on Tuesday, ejecting across the Plains and into the MS Valley on Wednesday. Some severe potential could return to parts of the central or south-central states toward the end of the period with this system, but current model forecasts suggest moisture return in the wake of the Day 4/5 system will remain poor. Trends will be monitored over the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Wed Mar 12 2025 Valid 151200Z - 201200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/SAT... ...DISCUSSION... ...Day 4/Sat - Central Gulf Coast States to the Ohio Valley... A strong large-scale upper trough is forecast to quickly move across the Plains to the MS Valley on Saturday. An intense jet streak will move across the Deep South into the OH Valley as this occurs. At the surface, a low secondary to the 980 mb low over the Upper Midwest is forecast to develop during the late morning/early afternoon across the mid-South. This will aid in further northward transport of rich Gulf moisture into portions of the Lower MS Valley and TN Valleys. Atop this moisture-primed boundary layer, cold 500 mb temperatures are forecast. This may support fairly steep lapse rates, which would foster moderate instability across portions of MS/AL amid supercell wind profiles. However, some uncertainty remains tied to the evolution of convection in the Day 3/Fri period into the morning hours of Saturday. Some forecast guidance suggests a relatively pristine warm sector will be maintained, or if only isolated convection develops overnight/early Saturday, recovery could occur. If this scenario unfolds, a concerning severe weather setup supporting all-hazard severe could unfold across portions of LA/MS/AL through the day and into evening, and eventually spreading east into GA overnight. Trends will be monitored closely over the coming days and further adjustments to the 30 percent/Enhanced risk area may be needed in future outlooks. With northward extent, instability will become more limited. Nevertheless, sufficient moisture amid intense deep-layer flow will support swaths of strong/damaging winds into the Ohio Valley and portions of the central Appalachians Saturday and Saturday night. Higher outlook probabilities may be needed in subsequent outlooks if confidence increases. ...Day 5/Sun - North Florida into the Carolinas and Mid-Atlantic... A strong upper trough will shift east across the Midwest and Southeast on Sunday. Strong deep-layer southwesterly flow ahead of the trough will overspread much of the eastern U.S. atop a moist boundary layer. Bands of convection will likely produce swaths of strong to severe gusts ahead of an eastward-advancing cold front. ...Days 6-8/Mon-Wed... An upper trough will move offshore over the Atlantic on Monday, while a broad upper ridge spreads across the Plains in its wake. Another large-scale upper trough will move across the western U.S. on Tuesday, ejecting across the Plains and into the MS Valley on Wednesday. Some severe potential could return to parts of the central or south-central states toward the end of the period with this system, but current model forecasts suggest moisture return in the wake of the Day 4/5 system will remain poor. Trends will be monitored over the coming days. Read more