SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 2000 UTC Day 1 Convective Outlook

7 months 1 week ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Dec 26 2024 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING IN SOUTHEAST TEXAS... ...SUMMARY... Several tornadoes, including a strong (potentially EF2+) tornado or two, will be possible this afternoon/evening across southeast Texas. Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter will also be possible from east Texas this afternoon into Louisiana, southern Arkansas and far west central Mississippi overnight. ...20Z Update... Severe probabilities in parts of central Texas have been adjusted to account for the progression of ongoing convection. Quasi-discrete supercells continue in parts of southeast Texas as well as to the northwest of Houston. These storms will continue to post the greatest threat for tornadoes (potentially strong). See MCD 2284 and 2285 for additional short-term, mesoscale details. ..Wendt.. 12/26/2024 .PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/ ...East TX/LA/southern AR through tonight... Elevated convection has already formed over north central TX this morning in a band of ascent preceding a midlevel shortwave trough moving eastward. New thunderstorm development is expected through the afternoon farther to the south and east across east/southeast TX, as the warm sector spreads northward in advance of a weak surface cyclone. Boundary-layer dewpoints in the mid-upper 60s beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging from 500 J/kg a little south of I-20 to 1500-2000 J/kg across southeast TX by late afternoon, where surface-based storms are likely with small breaks in the stratus. Vertical shear profiles will be characterized by sufficiently long hodographs (effective bulk shear in excess of 45 kt) and low-level hodograph curvature (effective SRH in excess of 200 m2/s2) for supercells. The initial storms will be more cellular across southeast TX with a gradual transition to a mixed mode/band of storms this evening into tonight as the storms spread eastward/northeastward across LA/southern AR. The surface-based supercells in southeast TX will be capable of producing tornadoes from early afternoon into late evening (including a strong/EF2+ tornado or two), along with isolated large hail (1-1.75 inches in diameter). With the gradual change in storms to a more linear mode, the potential for wind damage (and embedded tornadoes) will persist into tonight. Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more

SPC Dec 26, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

7 months 1 week ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0133 PM CST Thu Dec 26 2024 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH-CENTRAL LOUISIANA ACROSS MUCH OF CENTRAL MISSISSIPPI AND INTO FAR WEST-CENTRAL ALABAMA.... ...SUMMARY... Severe storms are expected Saturday from north-central Louisiana to west-central Alabama on Saturday. All severe weather hazards are possible. ...Synopsis... A mid-level trough centered across the Texas Panhandle will move quickly across the southern Plains and become negatively tilted across the Ozarks by Saturday evening and into the Ohio Valley by Sunday morning. Rich low-level moisture will start to move inland across the Gulf Coast by 12Z Saturday and continue to advance inland through the day as low-level flow strengthens across the warm sector ahead of the surface low. ...Lower/Mid Mississippi Valley across the Southeast... A broad warm sector will be advancing inland across the Gulf Coast states Saturday morning as low-level flow strengthens ahead of the approaching trough. Initially, the warm sector will likely be mostly uncontaminated, but thunderstorm activity is expected to increase through the morning as the low-level jet strengthens. The timing and location of this morning convection will have a significant impact on the location and intensity of the severe weather threat on Saturday. Variance amongst forecast guidance unsurprisingly remains high given the very progressive mid-level pattern. Despite the uncertainty on specifics, a broad warm sector with mid 60s dewpoints, a negatively tilted trough, and a strengthening low-level jet will support the potential for a severe weather outbreak with multiple rounds of storms with all severe weather hazards possible. Given the timing/amplitude differences with the mid-level pattern, the highest threat corridor will likely shift in future outlooks. The GEFS is slightly slower than the operational GFS with the EPS slightly faster than the ECMWF suggesting a most likely solution somewhere in between. Within the enhanced risk corridor, forecast soundings show 45 to 50 knots of effective shear and instability ranging from 1000 to 2000 J/kg MLCAPE. This will support supercells with all severe weather hazards across much of the warm sector from northern Louisiana to western Alabama as early as late morning. The tornado threat remains more uncertain based on the final evolution of the mid-level trough. A slower trough ejection (such as is shown by the ECMWF) may cause more issues with destabilization and less favorable low-level hodographs as the low-level jet ramp up is delayed. The severe weather threat is expected to continue after dark from central Mississippi into western Alabama. Somewhere near central Alabama the convective intensity will likely start to wane as the mid-level trough starts to pull away and heights start to rise across the warm sector. ..Bentley.. 12/26/2024 Read more