Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sun Feb 04 2024 Valid 041630Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN GEORGIA AND FLORIDA...AND PORTIONS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Local severe risk will continue across a small portion of southeastern FL, with low/additional risk possible across parts of FL later today/tonight. A very limited risk for a brief/weak tornado is also evident near the central California Coast, mainly this afternoon. ...Parts of FL... A band of strong/locally severe storms is crossing southeastern FL at this time, with one rotating storm now moving through the Miami area. This convection is advancing quickly northeastward, with the strongest storms to move offshore over the next half hour. As this occurs, severe risk will end in the short term. For additional details, please refer to SWOMCD #105. With severe risk to largely move off the coast in the very near term, will remove SLGT risk from this region. Later today, in the wake of the initial/ongoing convection, weak destabilization is expected -- aided by steepening lapse rates spreading across the Gulf and into Florida. Low-topped afternoon showers and isolated storms are expected to evolve from southern Georgia into northern Florida, where limited potential for marginal hail and a stronger gust or two could develop. Finally, convection developing over the Gulf south of Louisiana -- associated with a lobe of vorticity on the southern edge of the primary upper cyclone -- should continue to expand in coverage, and may reach coastal Florida and the Keys very late in the period. As such, will maintain low severe-weather probabilities across parts of southern Florida and the Keys to reflect this potential. ...Central CA coast... As a short-wave trough -- within the broader cyclonic circulation off the CA coast -- shifts northeastward toward the central coast today, an associated/well-developed surface low will also approach later today and tonight. As convection ahead of the low/cold front should moves onshore, little lightning is expected given very meager/low-topped buoyancy. Still, very strong deep-layer flow -- veering and increasing strongly with height ahead of the front -- will provide a highly favorable kinematic environment with respect to potential for rotating updrafts. The aforementioned lack of appreciable buoyancy should largely mitigate the potential for updrafts of sufficient depth/duration to realize to otherwise favorable low-level and deep-layer shear, but will maintain MRGL risk to reflect the very low/conditional potential for a brief tornado or strong wind gusts that could evolve as convection moves onshore later this afternoon/evening. ..Goss/Thornton.. 02/04/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sun Feb 04 2024 Valid 041630Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN GEORGIA AND FLORIDA...AND PORTIONS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Local severe risk will continue across a small portion of southeastern FL, with low/additional risk possible across parts of FL later today/tonight. A very limited risk for a brief/weak tornado is also evident near the central California Coast, mainly this afternoon. ...Parts of FL... A band of strong/locally severe storms is crossing southeastern FL at this time, with one rotating storm now moving through the Miami area. This convection is advancing quickly northeastward, with the strongest storms to move offshore over the next half hour. As this occurs, severe risk will end in the short term. For additional details, please refer to SWOMCD #105. With severe risk to largely move off the coast in the very near term, will remove SLGT risk from this region. Later today, in the wake of the initial/ongoing convection, weak destabilization is expected -- aided by steepening lapse rates spreading across the Gulf and into Florida. Low-topped afternoon showers and isolated storms are expected to evolve from southern Georgia into northern Florida, where limited potential for marginal hail and a stronger gust or two could develop. Finally, convection developing over the Gulf south of Louisiana -- associated with a lobe of vorticity on the southern edge of the primary upper cyclone -- should continue to expand in coverage, and may reach coastal Florida and the Keys very late in the period. As such, will maintain low severe-weather probabilities across parts of southern Florida and the Keys to reflect this potential. ...Central CA coast... As a short-wave trough -- within the broader cyclonic circulation off the CA coast -- shifts northeastward toward the central coast today, an associated/well-developed surface low will also approach later today and tonight. As convection ahead of the low/cold front should moves onshore, little lightning is expected given very meager/low-topped buoyancy. Still, very strong deep-layer flow -- veering and increasing strongly with height ahead of the front -- will provide a highly favorable kinematic environment with respect to potential for rotating updrafts. The aforementioned lack of appreciable buoyancy should largely mitigate the potential for updrafts of sufficient depth/duration to realize to otherwise favorable low-level and deep-layer shear, but will maintain MRGL risk to reflect the very low/conditional potential for a brief tornado or strong wind gusts that could evolve as convection moves onshore later this afternoon/evening. ..Goss/Thornton.. 02/04/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sun Feb 04 2024 Valid 041630Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN GEORGIA AND FLORIDA...AND PORTIONS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Local severe risk will continue across a small portion of southeastern FL, with low/additional risk possible across parts of FL later today/tonight. A very limited risk for a brief/weak tornado is also evident near the central California Coast, mainly this afternoon. ...Parts of FL... A band of strong/locally severe storms is crossing southeastern FL at this time, with one rotating storm now moving through the Miami area. This convection is advancing quickly northeastward, with the strongest storms to move offshore over the next half hour. As this occurs, severe risk will end in the short term. For additional details, please refer to SWOMCD #105. With severe risk to largely move off the coast in the very near term, will remove SLGT risk from this region. Later today, in the wake of the initial/ongoing convection, weak destabilization is expected -- aided by steepening lapse rates spreading across the Gulf and into Florida. Low-topped afternoon showers and isolated storms are expected to evolve from southern Georgia into northern Florida, where limited potential for marginal hail and a stronger gust or two could develop. Finally, convection developing over the Gulf south of Louisiana -- associated with a lobe of vorticity on the southern edge of the primary upper cyclone -- should continue to expand in coverage, and may reach coastal Florida and the Keys very late in the period. As such, will maintain low severe-weather probabilities across parts of southern Florida and the Keys to reflect this potential. ...Central CA coast... As a short-wave trough -- within the broader cyclonic circulation off the CA coast -- shifts northeastward toward the central coast today, an associated/well-developed surface low will also approach later today and tonight. As convection ahead of the low/cold front should moves onshore, little lightning is expected given very meager/low-topped buoyancy. Still, very strong deep-layer flow -- veering and increasing strongly with height ahead of the front -- will provide a highly favorable kinematic environment with respect to potential for rotating updrafts. The aforementioned lack of appreciable buoyancy should largely mitigate the potential for updrafts of sufficient depth/duration to realize to otherwise favorable low-level and deep-layer shear, but will maintain MRGL risk to reflect the very low/conditional potential for a brief tornado or strong wind gusts that could evolve as convection moves onshore later this afternoon/evening. ..Goss/Thornton.. 02/04/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sun Feb 04 2024 Valid 041630Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN GEORGIA AND FLORIDA...AND PORTIONS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Local severe risk will continue across a small portion of southeastern FL, with low/additional risk possible across parts of FL later today/tonight. A very limited risk for a brief/weak tornado is also evident near the central California Coast, mainly this afternoon. ...Parts of FL... A band of strong/locally severe storms is crossing southeastern FL at this time, with one rotating storm now moving through the Miami area. This convection is advancing quickly northeastward, with the strongest storms to move offshore over the next half hour. As this occurs, severe risk will end in the short term. For additional details, please refer to SWOMCD #105. With severe risk to largely move off the coast in the very near term, will remove SLGT risk from this region. Later today, in the wake of the initial/ongoing convection, weak destabilization is expected -- aided by steepening lapse rates spreading across the Gulf and into Florida. Low-topped afternoon showers and isolated storms are expected to evolve from southern Georgia into northern Florida, where limited potential for marginal hail and a stronger gust or two could develop. Finally, convection developing over the Gulf south of Louisiana -- associated with a lobe of vorticity on the southern edge of the primary upper cyclone -- should continue to expand in coverage, and may reach coastal Florida and the Keys very late in the period. As such, will maintain low severe-weather probabilities across parts of southern Florida and the Keys to reflect this potential. ...Central CA coast... As a short-wave trough -- within the broader cyclonic circulation off the CA coast -- shifts northeastward toward the central coast today, an associated/well-developed surface low will also approach later today and tonight. As convection ahead of the low/cold front should moves onshore, little lightning is expected given very meager/low-topped buoyancy. Still, very strong deep-layer flow -- veering and increasing strongly with height ahead of the front -- will provide a highly favorable kinematic environment with respect to potential for rotating updrafts. The aforementioned lack of appreciable buoyancy should largely mitigate the potential for updrafts of sufficient depth/duration to realize to otherwise favorable low-level and deep-layer shear, but will maintain MRGL risk to reflect the very low/conditional potential for a brief tornado or strong wind gusts that could evolve as convection moves onshore later this afternoon/evening. ..Goss/Thornton.. 02/04/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Sun Feb 04 2024 Valid 041630Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN GEORGIA AND FLORIDA...AND PORTIONS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Local severe risk will continue across a small portion of southeastern FL, with low/additional risk possible across parts of FL later today/tonight. A very limited risk for a brief/weak tornado is also evident near the central California Coast, mainly this afternoon. ...Parts of FL... A band of strong/locally severe storms is crossing southeastern FL at this time, with one rotating storm now moving through the Miami area. This convection is advancing quickly northeastward, with the strongest storms to move offshore over the next half hour. As this occurs, severe risk will end in the short term. For additional details, please refer to SWOMCD #105. With severe risk to largely move off the coast in the very near term, will remove SLGT risk from this region. Later today, in the wake of the initial/ongoing convection, weak destabilization is expected -- aided by steepening lapse rates spreading across the Gulf and into Florida. Low-topped afternoon showers and isolated storms are expected to evolve from southern Georgia into northern Florida, where limited potential for marginal hail and a stronger gust or two could develop. Finally, convection developing over the Gulf south of Louisiana -- associated with a lobe of vorticity on the southern edge of the primary upper cyclone -- should continue to expand in coverage, and may reach coastal Florida and the Keys very late in the period. As such, will maintain low severe-weather probabilities across parts of southern Florida and the Keys to reflect this potential. ...Central CA coast... As a short-wave trough -- within the broader cyclonic circulation off the CA coast -- shifts northeastward toward the central coast today, an associated/well-developed surface low will also approach later today and tonight. As convection ahead of the low/cold front should moves onshore, little lightning is expected given very meager/low-topped buoyancy. Still, very strong deep-layer flow -- veering and increasing strongly with height ahead of the front -- will provide a highly favorable kinematic environment with respect to potential for rotating updrafts. The aforementioned lack of appreciable buoyancy should largely mitigate the potential for updrafts of sufficient depth/duration to realize to otherwise favorable low-level and deep-layer shear, but will maintain MRGL risk to reflect the very low/conditional potential for a brief tornado or strong wind gusts that could evolve as convection moves onshore later this afternoon/evening. ..Goss/Thornton.. 02/04/2024 Read more

WW 0014 Status Updates
STATUS REPORT ON WW 14 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SW EYW TO 25 SW EYW TO 25 NNW MTH TO 50 N MTH TO 45 W MIA TO 35 E FMY. ..MOSIER..02/04/24 ATTN...WFO...MFL...TBW...KEY... STATUS REPORT FOR WT 14 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC011-051-086-087-099-041640- FL . FLORIDA COUNTIES INCLUDED ARE BROWARD HENDRY MIAMI-DADE MONROE PALM BEACH AMZ630-650-651-GMZ031-032-042-043-044-052-053-054-041640- CW . ADJACENT COASTAL WATERS INCLUDED ARE BISCAYNE BAY COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH FL OUT 20 NM COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF FL OUT 20 NM FLORIDA BAY INCLUDING BARNES SOUND BLACKWATER SOUND AND BUTTONWOOD SOUND BAYSIDE AND GULF SIDE FROM CRAIG KEY TO WEST END OF SEVEN MILE Read more

WW 0014 Status Updates
STATUS REPORT ON WW 14 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SW EYW TO 25 SW EYW TO 25 NNW MTH TO 50 N MTH TO 45 W MIA TO 35 E FMY. ..MOSIER..02/04/24 ATTN...WFO...MFL...TBW...KEY... STATUS REPORT FOR WT 14 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC011-051-086-087-099-041640- FL . FLORIDA COUNTIES INCLUDED ARE BROWARD HENDRY MIAMI-DADE MONROE PALM BEACH AMZ630-650-651-GMZ031-032-042-043-044-052-053-054-041640- CW . ADJACENT COASTAL WATERS INCLUDED ARE BISCAYNE BAY COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH FL OUT 20 NM COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF FL OUT 20 NM FLORIDA BAY INCLUDING BARNES SOUND BLACKWATER SOUND AND BUTTONWOOD SOUND BAYSIDE AND GULF SIDE FROM CRAIG KEY TO WEST END OF SEVEN MILE Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Sun Feb 04 2024 Valid 041300Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF SOUTHERN FLORIDA AND THE KEYS... ...SUMMARY... Severe thunderstorms are possible over southern Florida the next several hours and may develop again later today into tonight over parts of the peninsula. A low-end tornado threat may develop near parts of the central California Coast, mainly this afternoon. ...Synopsis... A highly amplified mid/upper level pattern will feature two substantial synoptic troughs/cyclones with convective implications: 1. A strongly negatively tilted trough from the central Rockies to the central/northern Gulf, with embedded circulation centers apparent in moisture-channel imagery over the TX Panhandle and northeast TX. The eastern center will take over and become a well-defined 500-mb low, moving southeastward across LA today into this evening, then over or just south of the western coastal FL Panhandle by 12Z tomorrow. Two basal shortwave troughs are apparent: a. Over the east-central Gulf, immediately preceded by a line of thunderstorms (see below), and forecast to eject northeastward over the FL Peninsula today. b. Over the lower/middle TX Coast, forecast to pivot southeastward then eastward across the central/eastern Gulf today and tonight, weakening as it approaches southwestern FL and the Keys between 06-12Z tomorrow. 2. A roughly south/north-elongated cyclone off the Pacific Coast, with several embedded vorticity maxima and at least transient circulation centers. The mean 500-mb center should remain offshore from northern CA trough the period, but drift eastward toward the coast. A well-defined, basal shortwave is evident west of southern CA near 130W, and should eject northeastward today, reaching the central CA coastline around 00Z. Surface analysis showed an occluded low inland of the Gulf Coast, over southern MS, and another low over the north-central/ northeastern Gulf around 125-150 nm south of MOB. A remnant Pacific cold front arched southeastward from that low, west of the Dry Tortugas, then southwestward toward the Yucatan Peninsula. This boundary should become more diffuse through the day, in deference to greater baroclinicity related to convective outflow just ahead of it. The low should move inland over the FL Panhandle this afternoon, reaching southeastern AL this evening before weakening. A warm front was approaching southwestern FL and the Keys, just ahead of the convection, and will remain close to the leading part of the thunderstorms as they cross south FL. ...FL... Multiple rounds of convection with at least marginal severe potential are possible through the period, with the greatest confidence in the "slight risk" area accompanying activity now approaching the southern part of the peninsula. This initial activity has formed and maintained as the large-scale ascent/DCVA and related low/middle-level lapse rates have shifted atop the warm Loop Current, aided by lift associated with a remnant Pacific front. A destabilizing (but not fully modified) return-flow airmass will immediately precede this activity across southern FL this morning, supporting potential for damaging gusts and isolated hail. An embedded tornado or two also cannot be ruled out. See tornado watch 14 and related mesoscale discussions for near-term details on this threat. A more-conditional severe threat will develop farther north, both over inland areas ahead of the northern part of the initial MCS, and in the zone of potential destabilization behind it. With residual moisture behind the morning complex, and perhaps a narrow corridor of moist advection around the western rim of the old outflow pool, around 500-1500 J/kg MLCAPE may develop by late afternoon. This will be possible as strong cooling aloft overlies a corridor of diabatic surface heating/destabilization. Favorable deep shear (effective-shear magnitudes 50-65 kt) will be present. The largest hodographs will be present from midday into mid/afternoon with southeasterly near-surface winds, however, that flow will be advecting convectively processes air from south FL. Hodographs should shrink thereafter, but still remain somewhat favorable for supercells. Uncertainties on convective coverage and amount of recovery behind the initial complex still preclude greater unconditional probabilities. Overnight, additional MCS development is progged over the central Gulf ahead of the second shortwave trough, but with the activity possibly weakening as it approaches southern FL and the Keys the last few hours of the period. That trend would be related to both nocturnal stabilization inland, and weakening/ejection of the shortwave trough northeastward away from the complex. Still, potential may exist for strong to marginally severe convection to reach these areas before 12Z. ...CA... Net columnar destabilization related to low-level warm advection, then midlevel cooling, should occur through the day. This, atop the moist marine layer, should lead to just enough destabilization of low/middle-level lapse rates for surface-based convection, including sporadic thunderstorms. SBCAPE and MLCAPE in the 100-300 J/kg range should become common after about 21Z. Time series of forecast soundings suggests a few-hour window where flow is not yet too veered to support enlarged hodographs and supercell-favorable deep shear, with effective-shear magnitudes around 35-45-kt possible. Given these profiles, fast-moving, low-topped convection may pose a threat for strong to marginally severe gusts and/or a brief tornado. ..Edwards/Leitman.. 02/04/2024 Read more

WW 0014 Status Updates
STATUS FOR WATCH 0014 HAS NOT BEEN ISSUED YET Read more

WW 0014 Status Updates
STATUS FOR WATCH 0014 HAS NOT BEEN ISSUED YET Read more

MD 0104 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF SOUTH FL AND THE FL KEYS
Mesoscale Discussion 0104 NWS Storm Prediction Center Norman OK 0545 AM CST Sun Feb 04 2024 Areas affected...portions of south FL and the FL Keys Concerning...Severe potential...Watch likely Valid 041145Z - 041245Z Probability of Watch Issuance...80 percent SUMMARY...Severe-thunderstorm potential will increase through early morning as a line of convection develops eastward toward the southwest FL coast and the Keys. Isolated damaging gusts and a couple of tornadoes are possible. A watch will likely be needed by 13z. DISCUSSION...A line of convection associated with an eastward- developing MCS over the eastern Gulf of Mexico will approach the southwest FL coast and the Keys over the next few hours. Boundary-layer dewpoints remain modest, in the upper 50s to low 60s F. Only minor increases in surface dewpoints are expected before convection begins moving across the southern Peninsula. Rather modest moisture and poor low-level lapse rates will limit instability, with generally less than 500-1000 J/kg MLCAPE expected. Nevertheless, 0-6 km bulk effective shear values around 35-45 kt will support organized convection. Regional VWP data indicate somewhat enlarged and curved low-level hodographs becoming elongated above 2-3 km. This should support at least transient strong to severe storms posing a risk for damaging gusts within the convective line. Although low-level moisture/thermodynamics are forecast to remain weak, favorable shear may still be sufficient for a couple of tornadoes, especially over the Keys or the far south Peninsula where surface dewpoints may approach 63-65 F through late morning. ..Leitman/Edwards.. 02/04/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...KEY...TBW... LAT...LON 27078258 26958043 26447999 25288019 24798053 24428125 24388192 24588229 26358270 26898273 27078258 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CST Sun Feb 04 2024 Valid 071200Z - 121200Z ...DISCUSSION... Low-end severe potential is evident on D5, possibly lingering into early D6 in parts of the south-central states. Greater conditional severe potential with potentially a more favorable synoptic pattern is evident next weekend into early next week over the South. Large-scale agreement remains strong with the ejection of a shortwave trough over the Lower CO Valley early Wednesday towards the Dakotas by Thursday afternoon. A lee surface cyclone will initially deepen over the central High Plains and similarly track northeastward into MN. A broad and fast southwesterly mid-level jet will become centered from the southern Great Plains northeastward into the Midwest on Thursday. This should overlap the northern extent of a relatively confined, modifying warm-moist sector emanating north from the western Gulf. Instability progs appear rather limited amid modest mid-level lapse rates atop the warm-moist sector. Consensus convective signal is for thunderstorm development to increase into Thursday night within the low-level warm conveyor. Despite strong mid to upper flow, severe potential will probably remain lower-end and isolated. In the wake of the aforementioned upper trough, 00Z deterministic guidance provides the illusion of consistency with the evolution of upstream shortwave troughs over the West. However, poor run-to-run continuity along with large spread within respective ensembles, both yield fairly low predictability next weekend. Still, with further increases in both the amplitude and breadth of the Gulf moisture plume and likelihood of an elevated mixed layer to support steep mid-level lapse rates (at least across TX), a more prominent severe weather episode may unfold next weekend into early next week from the southern Great Plains to the Southeast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CST Sun Feb 04 2024 Valid 071200Z - 121200Z ...DISCUSSION... Low-end severe potential is evident on D5, possibly lingering into early D6 in parts of the south-central states. Greater conditional severe potential with potentially a more favorable synoptic pattern is evident next weekend into early next week over the South. Large-scale agreement remains strong with the ejection of a shortwave trough over the Lower CO Valley early Wednesday towards the Dakotas by Thursday afternoon. A lee surface cyclone will initially deepen over the central High Plains and similarly track northeastward into MN. A broad and fast southwesterly mid-level jet will become centered from the southern Great Plains northeastward into the Midwest on Thursday. This should overlap the northern extent of a relatively confined, modifying warm-moist sector emanating north from the western Gulf. Instability progs appear rather limited amid modest mid-level lapse rates atop the warm-moist sector. Consensus convective signal is for thunderstorm development to increase into Thursday night within the low-level warm conveyor. Despite strong mid to upper flow, severe potential will probably remain lower-end and isolated. In the wake of the aforementioned upper trough, 00Z deterministic guidance provides the illusion of consistency with the evolution of upstream shortwave troughs over the West. However, poor run-to-run continuity along with large spread within respective ensembles, both yield fairly low predictability next weekend. Still, with further increases in both the amplitude and breadth of the Gulf moisture plume and likelihood of an elevated mixed layer to support steep mid-level lapse rates (at least across TX), a more prominent severe weather episode may unfold next weekend into early next week from the southern Great Plains to the Southeast. Read more