Severe Storms

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

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

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

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Tue Jan 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears low over this area. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with a couple of possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. Other thunderstorms also appear possible late Thursday night into early Friday morning across a small portion of coastal TX as greater low-level moisture begins to return northward across this area. ..Gleason.. 01/02/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Tue Jan 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears low over this area. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with a couple of possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. Other thunderstorms also appear possible late Thursday night into early Friday morning across a small portion of coastal TX as greater low-level moisture begins to return northward across this area. ..Gleason.. 01/02/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Tue Jan 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears low over this area. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with a couple of possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. Other thunderstorms also appear possible late Thursday night into early Friday morning across a small portion of coastal TX as greater low-level moisture begins to return northward across this area. ..Gleason.. 01/02/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Tue Jan 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur Thursday across parts of the southern Plains and coastal Texas. Severe thunderstorms are not expected. ...Synopsis and Discussion... A cold front will move southward over the central/southern FL Peninsula on Thursday. But, with limited low-level convergence along this boundary, thunderstorm potential appears low over this area. In its wake, a large area of surface high pressure will dominate much of the central/eastern states through the period. A lack of appreciable low-level moisture should hinder thunderstorm develop for a large majority of the CONUS, with a couple of possible exceptions over the southern Plains and coastal TX. A pronounced upper trough/low with attendant strong large-scale ascent will eject over the southern Plains through the day. Even though surface temperatures will remain cool and low-level moisture quite limited, weak instability may still develop with modest daytime heating over parts of the southern High Plains. Isolated, low-topped thunderstorms may occur in this regime as mid-level temperatures rapidly cool with the approach of the upper trough. Other thunderstorms also appear possible late Thursday night into early Friday morning across a small portion of coastal TX as greater low-level moisture begins to return northward across this area. ..Gleason.. 01/02/2024 Read more