Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CST Tue Jan 02 2024 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Central/Eastern Gulf Coast States... A southern-stream shortwave trough should gradually dampen as it progresses from the northwest Gulf Coast to off the South Atlantic Coast by 12Z Thursday. Guidance is rather consistent that rich low-level moisture will remain confined offshore across the northern Gulf, suggesting prospects will be slim for SBCAPE over land. Weak elevated buoyancy may support sporadic thunderstorms shifting from west to east through the period. The greatest thunder probabilities are across southeast LA early, with low chances farther east as the bulk of deep convection is expected to remain across the north-central to northeast Gulf. ...Coastal CA and AZ/NM... The southern one of the pair of shortwave impulses over the West Coast States should dig slightly as it progresses across the Lower CO Valley into AZ by early Thursday. Relatively cold mid-level temperatures from -25 to -30 C near 500 mb will expand/shift south and overlap scant surface-based buoyancy amid west-northwesterly low-level flow along the CA coast. This may yield very isolated thunderstorm coverage shifting from north to south, mainly during the first half of the period. The modest amplification of the shortwave trough on Wednesday night should strengthen large-scale ascent for low-topped convection across a portion of AZ to west NM. Scant buoyancy may support sporadic lightning flashes. ..Grams.. 01/02/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Tue Jan 02 2024 Valid 021700Z - 031200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 01/02/2024 .PREV DISCUSSION... /ISSUED 1238 AM CST Tue Jan 02 2024/ ...Synopsis... Fire weather concerns will be minimal for today. Cool conditions prevail in the wake of a recent cold frontal passage across the Plains and Southeast. Surface high pressure in place over the mid-MS River Valley will maintain generally light winds for today. The combination of cool conditions and weak winds over much of the country (as well as precipitation chances over the southern High Plains/TX where fuels have undergone some recent drying) will limit the potential for fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Tue Jan 02 2024 Valid 021700Z - 031200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 01/02/2024 .PREV DISCUSSION... /ISSUED 1238 AM CST Tue Jan 02 2024/ ...Synopsis... Fire weather concerns will be minimal for today. Cool conditions prevail in the wake of a recent cold frontal passage across the Plains and Southeast. Surface high pressure in place over the mid-MS River Valley will maintain generally light winds for today. The combination of cool conditions and weak winds over much of the country (as well as precipitation chances over the southern High Plains/TX where fuels have undergone some recent drying) will limit the potential for fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Tue Jan 02 2024 Valid 021700Z - 031200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 01/02/2024 .PREV DISCUSSION... /ISSUED 1238 AM CST Tue Jan 02 2024/ ...Synopsis... Fire weather concerns will be minimal for today. Cool conditions prevail in the wake of a recent cold frontal passage across the Plains and Southeast. Surface high pressure in place over the mid-MS River Valley will maintain generally light winds for today. The combination of cool conditions and weak winds over much of the country (as well as precipitation chances over the southern High Plains/TX where fuels have undergone some recent drying) will limit the potential for fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Tue Jan 02 2024 Valid 021700Z - 031200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 01/02/2024 .PREV DISCUSSION... /ISSUED 1238 AM CST Tue Jan 02 2024/ ...Synopsis... Fire weather concerns will be minimal for today. Cool conditions prevail in the wake of a recent cold frontal passage across the Plains and Southeast. Surface high pressure in place over the mid-MS River Valley will maintain generally light winds for today. The combination of cool conditions and weak winds over much of the country (as well as precipitation chances over the southern High Plains/TX where fuels have undergone some recent drying) will limit the potential for fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Tue Jan 02 2024 Valid 021700Z - 031200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 01/02/2024 .PREV DISCUSSION... /ISSUED 1238 AM CST Tue Jan 02 2024/ ...Synopsis... Fire weather concerns will be minimal for today. Cool conditions prevail in the wake of a recent cold frontal passage across the Plains and Southeast. Surface high pressure in place over the mid-MS River Valley will maintain generally light winds for today. The combination of cool conditions and weak winds over much of the country (as well as precipitation chances over the southern High Plains/TX where fuels have undergone some recent drying) will limit the potential for fire weather concerns. ...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 1015 AM CST Tue Jan 02 2024 Valid 021630Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorms are expected in central Texas this afternoon and tonight into southeast Texas and southern Louisiana. Isolated thunderstorms will be possible this evening through tonight along the northern/central California coast. ...Synopsis... Within a southern stream, one shortwave trough will progress eastward from far west TX to the northwest Gulf coast by early Wednesday, as an upstream trough moves over CA. A modifying air mass is returning northward across the western Gulf of Mexico, though weak cyclogenesis across the shelf waters will keep the surface warm sector just offshore of all but the immediate lower TX coast. There will be some potential for a supercell or two over the near-shore waters of the middle/upper TX coast, but convection will subsequently move farther offshore, which suggests that any severe threat over land is too low to add any probabilities. Scattered/elevated thunderstorms will form farther inland in a zone of increasing ascent over central TX this afternoon, and storms will continue through tonight into southeast TX and southern LA. Otherwise, isolated thunderstorms will be possible later today into tonight across the northern/central CA coast as the upstream trough/midlevel cooling and steepening low-midlevel lapse rates spread inland. ..Thompson/Squitieri.. 01/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1015 AM CST Tue Jan 02 2024 Valid 021630Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorms are expected in central Texas this afternoon and tonight into southeast Texas and southern Louisiana. Isolated thunderstorms will be possible this evening through tonight along the northern/central California coast. ...Synopsis... Within a southern stream, one shortwave trough will progress eastward from far west TX to the northwest Gulf coast by early Wednesday, as an upstream trough moves over CA. A modifying air mass is returning northward across the western Gulf of Mexico, though weak cyclogenesis across the shelf waters will keep the surface warm sector just offshore of all but the immediate lower TX coast. There will be some potential for a supercell or two over the near-shore waters of the middle/upper TX coast, but convection will subsequently move farther offshore, which suggests that any severe threat over land is too low to add any probabilities. Scattered/elevated thunderstorms will form farther inland in a zone of increasing ascent over central TX this afternoon, and storms will continue through tonight into southeast TX and southern LA. Otherwise, isolated thunderstorms will be possible later today into tonight across the northern/central CA coast as the upstream trough/midlevel cooling and steepening low-midlevel lapse rates spread inland. ..Thompson/Squitieri.. 01/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1015 AM CST Tue Jan 02 2024 Valid 021630Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorms are expected in central Texas this afternoon and tonight into southeast Texas and southern Louisiana. Isolated thunderstorms will be possible this evening through tonight along the northern/central California coast. ...Synopsis... Within a southern stream, one shortwave trough will progress eastward from far west TX to the northwest Gulf coast by early Wednesday, as an upstream trough moves over CA. A modifying air mass is returning northward across the western Gulf of Mexico, though weak cyclogenesis across the shelf waters will keep the surface warm sector just offshore of all but the immediate lower TX coast. There will be some potential for a supercell or two over the near-shore waters of the middle/upper TX coast, but convection will subsequently move farther offshore, which suggests that any severe threat over land is too low to add any probabilities. Scattered/elevated thunderstorms will form farther inland in a zone of increasing ascent over central TX this afternoon, and storms will continue through tonight into southeast TX and southern LA. Otherwise, isolated thunderstorms will be possible later today into tonight across the northern/central CA coast as the upstream trough/midlevel cooling and steepening low-midlevel lapse rates spread inland. ..Thompson/Squitieri.. 01/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1015 AM CST Tue Jan 02 2024 Valid 021630Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorms are expected in central Texas this afternoon and tonight into southeast Texas and southern Louisiana. Isolated thunderstorms will be possible this evening through tonight along the northern/central California coast. ...Synopsis... Within a southern stream, one shortwave trough will progress eastward from far west TX to the northwest Gulf coast by early Wednesday, as an upstream trough moves over CA. A modifying air mass is returning northward across the western Gulf of Mexico, though weak cyclogenesis across the shelf waters will keep the surface warm sector just offshore of all but the immediate lower TX coast. There will be some potential for a supercell or two over the near-shore waters of the middle/upper TX coast, but convection will subsequently move farther offshore, which suggests that any severe threat over land is too low to add any probabilities. Scattered/elevated thunderstorms will form farther inland in a zone of increasing ascent over central TX this afternoon, and storms will continue through tonight into southeast TX and southern LA. Otherwise, isolated thunderstorms will be possible later today into tonight across the northern/central CA coast as the upstream trough/midlevel cooling and steepening low-midlevel lapse rates spread inland. ..Thompson/Squitieri.. 01/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1015 AM CST Tue Jan 02 2024 Valid 021630Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorms are expected in central Texas this afternoon and tonight into southeast Texas and southern Louisiana. Isolated thunderstorms will be possible this evening through tonight along the northern/central California coast. ...Synopsis... Within a southern stream, one shortwave trough will progress eastward from far west TX to the northwest Gulf coast by early Wednesday, as an upstream trough moves over CA. A modifying air mass is returning northward across the western Gulf of Mexico, though weak cyclogenesis across the shelf waters will keep the surface warm sector just offshore of all but the immediate lower TX coast. There will be some potential for a supercell or two over the near-shore waters of the middle/upper TX coast, but convection will subsequently move farther offshore, which suggests that any severe threat over land is too low to add any probabilities. Scattered/elevated thunderstorms will form farther inland in a zone of increasing ascent over central TX this afternoon, and storms will continue through tonight into southeast TX and southern LA. Otherwise, isolated thunderstorms will be possible later today into tonight across the northern/central CA coast as the upstream trough/midlevel cooling and steepening low-midlevel lapse rates spread inland. ..Thompson/Squitieri.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Tue Jan 02 2024 Valid 021300Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered non-severe thunderstorms are expected from central Texas during the day toward the Texas Coast and Sabine Valley through Wednesday morning. A few lightning flashes will also be possible along the coast of northern California. ...Synopsis... A mid to upper-level trough initially over NM and northern Mexico will move east across TX during the period. Upstream of the TX disturbance, a potent mid-level trough over the eastern Pacific will move eastward reaching the Sierra Nevada by early Wednesday morning. In the low levels, surface high pressure centered over the Mid South will move little during the period as weak surface reflection occurs near the TX coast in response to the approaching mid-level wave. A still modifying airmass over the western Gulf of Mexico will likely penetrate the immediate middle and lower coasts of TX with scant instability farther northwest over central TX. Models indicate elevated instability (MUCAPE 100-500 J/kg) north of a developing cold front that is forecast to push east of the coast during the evening. A corridor of developing showers and a few thunderstorms will shift east from central TX through the TX coast and the southern half of LA tonight, and severe thunderstorm activity is not forecast. ..Smith.. 01/02/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CST Tue Jan 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... An upper trough over the central CONUS, with multiple embedded mid-level shortwave troughs over the southern Plains, is forecast to move eastward across the Southeast and TN/OH Valleys on Day 4/Friday. Similar to prior systems, low-level mass response should encourage the northward advance of low-level moisture across the northern Gulf of Mexico and immediate coastal areas of TX/LA/MS/AL. While both low-level and deep-layer shear appear strong with this system, current expectations are that appreciable surface-based instability should struggle to reach very far inland. This will probably tend to limit the spatial extent of any severe risk over land Friday afternoon through Friday night from parts of coastal TX to the central Gulf Coast states. Still, a marginal/isolated severe risk may exist across these areas, and low severe probabilities may need to be included in a future outlook. Some severe threat may persist into Day 5/Saturday across parts of the Southeast as the upper trough and related surface low/cold front continue quickly east-northeastward. But, uncertainty regarding sufficient instability given poor lapse rates and modest low-level moisture precludes introduction of a severe area at this time. In the wake of this system, minimal severe potential is evident across the CONUS for Day 6/Sunday. Medium-range deterministic and ensemble guidance show remarkably good agreement that another upper trough will both strengthen and amplify as it ejects across the southern Plains and Southeast early next week. Impressive wind fields at low/mid levels should easily support severe thunderstorms wherever sufficient low-level moisture can advance inland of a deepening surface low. There is still some uncertainty with both how quickly rich low-level moisture will be able to return northward from the Gulf of Mexico into parts of TX and the lower MS Valley, and how far north it will reach. Regardless, it appears probable that enough boundary-layer instability will be present/develop on Day 7/Monday and Monday night over parts of coastal/east TX into LA, southern MS/AL, and the western FL Panhandle to justify introducing a 15% severe area. Adjustments to this area will likely be needed in the coming days as confidence increases in the northward extent of appreciable low-level moisture. But, given the very strong forecast shear, supercells and line segments capable of producing both tornadoes and damaging winds appear possible. This severe threat may continue farther east into Day 8/Tuesday from parts of FL/GA into the Carolinas, but too much uncertainty regarding destabilization currently exists to include a severe delineation across this region. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CST Tue Jan 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... An upper trough over the central CONUS, with multiple embedded mid-level shortwave troughs over the southern Plains, is forecast to move eastward across the Southeast and TN/OH Valleys on Day 4/Friday. Similar to prior systems, low-level mass response should encourage the northward advance of low-level moisture across the northern Gulf of Mexico and immediate coastal areas of TX/LA/MS/AL. While both low-level and deep-layer shear appear strong with this system, current expectations are that appreciable surface-based instability should struggle to reach very far inland. This will probably tend to limit the spatial extent of any severe risk over land Friday afternoon through Friday night from parts of coastal TX to the central Gulf Coast states. Still, a marginal/isolated severe risk may exist across these areas, and low severe probabilities may need to be included in a future outlook. Some severe threat may persist into Day 5/Saturday across parts of the Southeast as the upper trough and related surface low/cold front continue quickly east-northeastward. But, uncertainty regarding sufficient instability given poor lapse rates and modest low-level moisture precludes introduction of a severe area at this time. In the wake of this system, minimal severe potential is evident across the CONUS for Day 6/Sunday. Medium-range deterministic and ensemble guidance show remarkably good agreement that another upper trough will both strengthen and amplify as it ejects across the southern Plains and Southeast early next week. Impressive wind fields at low/mid levels should easily support severe thunderstorms wherever sufficient low-level moisture can advance inland of a deepening surface low. There is still some uncertainty with both how quickly rich low-level moisture will be able to return northward from the Gulf of Mexico into parts of TX and the lower MS Valley, and how far north it will reach. Regardless, it appears probable that enough boundary-layer instability will be present/develop on Day 7/Monday and Monday night over parts of coastal/east TX into LA, southern MS/AL, and the western FL Panhandle to justify introducing a 15% severe area. Adjustments to this area will likely be needed in the coming days as confidence increases in the northward extent of appreciable low-level moisture. But, given the very strong forecast shear, supercells and line segments capable of producing both tornadoes and damaging winds appear possible. This severe threat may continue farther east into Day 8/Tuesday from parts of FL/GA into the Carolinas, but too much uncertainty regarding destabilization currently exists to include a severe delineation across this region. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CST Tue Jan 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... An upper trough over the central CONUS, with multiple embedded mid-level shortwave troughs over the southern Plains, is forecast to move eastward across the Southeast and TN/OH Valleys on Day 4/Friday. Similar to prior systems, low-level mass response should encourage the northward advance of low-level moisture across the northern Gulf of Mexico and immediate coastal areas of TX/LA/MS/AL. While both low-level and deep-layer shear appear strong with this system, current expectations are that appreciable surface-based instability should struggle to reach very far inland. This will probably tend to limit the spatial extent of any severe risk over land Friday afternoon through Friday night from parts of coastal TX to the central Gulf Coast states. Still, a marginal/isolated severe risk may exist across these areas, and low severe probabilities may need to be included in a future outlook. Some severe threat may persist into Day 5/Saturday across parts of the Southeast as the upper trough and related surface low/cold front continue quickly east-northeastward. But, uncertainty regarding sufficient instability given poor lapse rates and modest low-level moisture precludes introduction of a severe area at this time. In the wake of this system, minimal severe potential is evident across the CONUS for Day 6/Sunday. Medium-range deterministic and ensemble guidance show remarkably good agreement that another upper trough will both strengthen and amplify as it ejects across the southern Plains and Southeast early next week. Impressive wind fields at low/mid levels should easily support severe thunderstorms wherever sufficient low-level moisture can advance inland of a deepening surface low. There is still some uncertainty with both how quickly rich low-level moisture will be able to return northward from the Gulf of Mexico into parts of TX and the lower MS Valley, and how far north it will reach. Regardless, it appears probable that enough boundary-layer instability will be present/develop on Day 7/Monday and Monday night over parts of coastal/east TX into LA, southern MS/AL, and the western FL Panhandle to justify introducing a 15% severe area. Adjustments to this area will likely be needed in the coming days as confidence increases in the northward extent of appreciable low-level moisture. But, given the very strong forecast shear, supercells and line segments capable of producing both tornadoes and damaging winds appear possible. This severe threat may continue farther east into Day 8/Tuesday from parts of FL/GA into the Carolinas, but too much uncertainty regarding destabilization currently exists to include a severe delineation across this region. Read more