Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 01 2024 Valid 011630Z - 021200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EXTREME NORTH TX INTO CENTRAL/EASTERN OK... ...SUMMARY... Severe thunderstorms with very large hail (2-3 inch diameter or greater), damaging gusts (60-80 mph) and a few tornadoes (potentially up to EF2) are expected this afternoon into tonight from north Texas and Oklahoma into the lower Ohio River Valley. ...Synopsis... Embedded speed maxima (90-100+ kt 500 mb) from southern NM/far west TX to northwest Mexico will eject northeastward to OK this evening and MO overnight. An associated lee cyclone will deepen this afternoon across the TX South Plains and then progress into northwest OK this evening and the mid MS Valley by the end of the period. A broad/moist warm sector is in place from the southern Plains to the mid MS/lower OH Valleys, beneath a warm elevated mixed layer with 8-9 C/km midlevel lapse rates. The cap will weaken through the afternoon from the west, with thunderstorm initiation becoming likely by mid afternoon along a surface front from KS into MO/IL, and mid-late afternoon along the dryline from western/central OK into northwest TX. ...KS/MO/IL/IN through tonight... Scattered thunderstorm development is likely starting mid afternoon along the baroclinic zone from KS into MO, and storms will subsequently spread eastward along the warm front from MO into IL/IN. The environment will favor supercells capable of producing very large hail (2-3 inches in diameter) and a few tornadoes, with an isolated strong tornado possible. Storm mode will become messier into the overnight hours with upscale growth into clusters/line segments, with an increase in the threat for damaging winds (60-80 mph), and a continued threat for tornadoes (possibly up to EF2) with embedded/QLCS circulations. ...OK/TX this afternoon into early tonight... The elevated mixed layer and associated cap, along with widespread clouds, will tend to delay surface-based storm development until mid-late afternoon, when forcing for ascent increases from the southwest with the approach of the mid-upper jet streak. By about 21z, scattered thunderstorm development is expected along the dryline from northwest TX into western OK, and storms will spread quickly northeastward into central/eastern OK through this evening/early tonight. Steep midlevel lapse rates and boundary-layer dewpoints in the mid-upper 60s will contribute to MLCAPE of 2000-3000 J/kg, in an environment with very strong deep-layer shear/long hodographs favorable for multiple supercells with very large hail (3 inches in diameter or greater). The magnitude of the tornado threat is a bit less certain, given a weakness in the low-level shear until a more consolidated low-level jet response begins by late evening, when storm mergers and upscale growth become more probable into eastern OK/northwest AR/southwest MO early tonight. However, given the very strong flow and seasonably rich low-level moisture, there will be the potential for a couple of strong (roughly EF2) tornadoes late this afternoon into tonight. ..Thompson/Wendt.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 01 2024 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER MISSOURI AND OHIO VALLEY REGIONS... ...SUMMARY... Severe thunderstorms are expected today into this evening within a broad swath from the southern Plains to the lower Missouri and Ohio Valley regions. Tornadoes (a few strong), destructive hail, and damaging thunderstorm gusts all are possible. ...Synopsis... The most important mid/upper-level feature for this forecast will be a deep, positively tilted, synoptic-scale trough, initially extending from the northern High Plains across UT to northern Baja. Several shortwave troughs and vorticity lobes will traverse the associated cyclonic flow, as the broader trough shifts eastward. By the end of the period, the synoptic trough should extend from IA across KS and the southern High Plains to far west TX and northwestern MX. A lead shortwave perturbation -- evident in moisture-channel imagery over the eastern AZ/western NM region and southward into adjoining parts of MX -- will eject across the southern High Plains today, reaching the TX Panhandle and western OK by 00Z. This feature should proceed northeastward to parts of northwestern MO and IA by 12Z tomorrow. Surface analysis at 11Z showed a frontal-wave low over central KS, with warm front to near a line from SZL-STL-ILN. The low should migrate along the slowly northward-moving warm front to MO by 00Z, with cold front southwestward across northwestern OK and the northernmost TX Panhandle. A dryline -- drawn initially from the low to the eastern TX Panhandle, near MAF, then southward into northern Coahuila -- should shift eastward through the afternoon to west-central/southwestern OK, extending southward across the TX Hill Country to near LRD. By 00Z, the warm front -- perhaps modulated on the mesoscale by areas of precip -- should extend across northern MO, central parts of IL/IN, to southern OH and parts of WV. A secondary low may form near the front/dryline intersection over western OK. By 12Z tomorrow, an elongated low-pressure area, with more than one center, is possible from the main frontal inflection over northeastern MO to central IN. The main cold front should reach southwestern MO, southeastern OK, northwest TX, and southeastern NM. To its southeast, a Pacific front should overtake the dryline this evening and overnight, reaching western AR, the Arklatex, east TX, and parts of deep south TX by the end of the period. ...Southeastern KS and western Ozarks to central TX... Scattered (OK/KS) to isolated (central TX) thunderstorms are expected to develop this afternoon along/ahead of the dryline and front, quickly becoming severe with all hazards possible. The hail threat will be greatest during the first few hours, while tornado potential ramps into a probable early-evening peak. Severe downdraft gusts also are possible, given the strong available buoyancy and fast cell motions expected. By late afternoon, much of OK and southeastern KS will reside under the left-exit region of a cyclonically curving jet streak, above strong low-level moisture transport accompanying a 50-65-kt LLJ. Initiation is expected as large-scale ascent preceding the lead shortwave starts to impinge upon a favorably heated dryline and moist sector, and the basal EML capping layer erodes. This may occur earlier over the northern OK/KS part of the outlook near the front. The environment will be favorable for frequent large hail and occasional significant to giant hailstones from any sustained supercells. MLCAPE of 2000-3000 J/kg is possible, amidst 60-75 kt effective-shear magnitudes. Forecast soundings indicate abundant inflow-layer moisture content to supply the updrafts, long hodographs commonly associated with significant hail (from right- or left-moving storms), as well as significant to giant hail in both historic analog soundings and a 2D hail-model. Though convective coverage may become densest north of the Red River, the potential for longer-lasting discrete modes near and south of the Red River conditionally favor isolated extreme hail sizes even into north TX. Given mesoscale uncertainties and inconsistent convection-allowing model signals regarding initiation timing (which influences what low-level shear/hodograph space cells will enter) and mature storm duration before upscale merging/linear evolution occur, will hold hail probabilities at previous levels for now. However, a "hail moderate" may become necessary in this region if mesoscale trends and post-12Z/today guidance become better focused on timing/density. The geometry of the pattern aloft will compel a strong component of mid/upper-level flow parallel to the convective alignment, encouraging eventual merging, training, and quasi-linear evolution. How long that process will take is uncertain, and the line ultimately may backbuild into central TX. Still, with LLJ-expanded hodographs and surface-based inflow parcels available in the early/mid evening, tornado potential (some strong) should exist with any remaining discrete storms, as well as in embedded QLCS mesocirculations. Severe potential should ramp down late tonight (after about 06Z) over this region, but persist longer in the next (below). ...Lower Missouri Valley to Ohio Valley... Multiple episodes of strong-severe thunderstorm development are expected this afternoon through tonight, each capable of all severe hazards. The distribution of severe weather over this corridor may be quite non-uniform/clustered, as mesoscale convective processes and boundaries evolve. Strong tornadoes may occur over parts of MO into central/southern IL while the afternoon/evening CAPE/shear parameter space and frontal proximity encourage potential development of at least a couple long-lasting supercells. Severe to isolated giant hail also is possible, especially from discrete supercells the western portion over MO/IL containing steepest lapse rates, greatest CAPE, and similarly favorable vertical wind profiles as the southern Plains area. Moist advection should quickly boost boundary-layer mixing ratios and dewpoints today, with surface dewpoints in the 60s common along and south of the warm front by midafternoon. Peak/preconvective MLCAPE should reach 2000-2500 J/kg south of the warm front over parts of MO/IL/IN, diminishing to 1000-1500 J/kg from the northeastern KY/southern OH area eastward. Effective-shear magnitudes should range from near 60 kt over MO to 40-50 kt in eastern parts of the outlook. An MCS may evolve this evening from convection over MO and sweep east-northeastward on either side of the warm front, reaching parts of IN/OH/northern KY late tonight before weakening. Though moving into an airmass that will be stabilizing near the surface -- with time and eastward extent -- such a complex may have enough forced ascent and downward momentum transfer behind that to maintain organized wind-damage potential over the Ohio Valley tonight. ..Edwards/Leitman.. 04/01/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0605 AM CDT Mon Apr 01 2024 Valid 021200Z - 031200Z ...Synopsis... A cold front will move south across Texas on Tuesday. In the wake of this cold front, dry and breezy conditions are expected. The best potential for Elevated fire weather conditions will be portions of the Texas Hill Country into far South Texas where sustained winds of 15 to 20 mph and relative humidity around 20 percent are expected. However, fuels have mostly greened up in this region and fuel availability may be limited. Therefore, an Elevated delineation was not added at this time. ..Bentley.. 04/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0605 AM CDT Mon Apr 01 2024 Valid 021200Z - 031200Z ...Synopsis... A cold front will move south across Texas on Tuesday. In the wake of this cold front, dry and breezy conditions are expected. The best potential for Elevated fire weather conditions will be portions of the Texas Hill Country into far South Texas where sustained winds of 15 to 20 mph and relative humidity around 20 percent are expected. However, fuels have mostly greened up in this region and fuel availability may be limited. Therefore, an Elevated delineation was not added at this time. ..Bentley.. 04/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more