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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Feb 05 2024 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... An amplified upper-level pattern will persist on Tuesday, as a deep trough in the West, ridge over the central states, and a deep trough over the East all move gradually eastward through the day. Relatively low-topped convection with sporadic lightning flashes will be possible across parts of the Southwest and southern CA. While a strong storm or two cannot be ruled out from the lower CO River Valley into western AZ, weak instability should generally limit the organized severe-thunderstorm threat. Isolated thunderstorms will also be possible near and offshore of the Florida Atlantic coast, as convection moves south-southwestward along the western periphery of a deep cyclone centered northeast of the Bahamas. ..Dean.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1024 AM CST Mon Feb 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather threat has diminished across Florida, with additional risk not expected there, or over the remainder of the country. ...Discussion... A positively tilted upper trough -- extending from near the Pacific Northwest Coast southwestward across the eastern Pacific -- will make gradual eastward progress today. Upstream, ridging will prevail over the central CONUS. Still further upstream, two upper lows will continue to affect the eastern U.S. through the period. The first -- lingering over the northwestern Atlantic southeast of the Canadian Maritimes -- will result in persistence of cyclonic northwesterly flow aloft across New England. The second low of interest is one that has drifted south into the northeastern Gulf of Mexico. This low is forecast to take a southeastward and then eastward turn with time, shifting into Florida late today, and then across the Peninsula tonight. At the surface, low pressure over the eastern Gulf is forecast to redevelop off eastern coast of Florida near the Bahamas by this evening. Currently, vigorous convection that was affecting the Keys and southern portions of the Peninsula has shifted east, with northerly low-level winds now over southern Florida in the wake of this convection and the associated outflow boundary. While weak instability lingers off the western Florida coast at this time, dewpoints are now in the 50s inland, and thus an accordingly stable airmass is indicated. As such, potential for any stronger convection inland has diminished substantially, and will gradually end entirely as the surface low redevelops off the eastern coast. As such, the MRGL risk is being removed at this time, with severe storms not expected across Florida, or the rest of the U.S., for the remainder of the period. ..Goss/Thornton.. 02/05/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Mon Feb 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire-weather concerns are low. See the prior discussion. ..Lyons.. 02/05/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Sun Feb 04 2024/ ...Synopsis... An upper ridge will build over the Plains states today between a mid-level trough ejecting into the Atlantic and a second trough impinging on the West Coast. Relatively cool temperatures with weak wind fields should characterize surface conditions across the Plains, with heavier precipitation falling along the West Coast and Gulf Coast areas, limiting significant wildfire-spread potential across much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0111 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE FL KEYS AND EXTREME SOUTHERN MAINLAND FL.
Mesoscale Discussion 0111 NWS Storm Prediction Center Norman OK 0730 AM CST Mon Feb 05 2024 Areas affected...Portions of the FL Keys and extreme southern mainland FL. Concerning...Severe potential...Watch unlikely Valid 051330Z - 051530Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong/damaging gusts, hail near severe limits, and conditional/brief tornado potential may occur with a band of thunderstorms moving up the Keys and brushing the southernmost mainland. DISCUSSION...At 1315Z, the primary band of thunderstorms extended from EYW to Cape Sable, along and south of an outflow boundary from earlier convection that was analyzed over northern portions of FL Bay and eastward across the Straits just southeast of HST. This activity occasionally has had an embedded supercell over open water, and has produced several reports of small hail, as well as strong/subsevere gusts around Key West (42 kt at EYW and 41 kt at NQX). While the predominant mode should remain quasi-linear, an additional/isolated supercell or bowing segment may develop within the band as it proceeds eastward over the remainder of FL Bay, the middle/upper Keys, and southern Miami-Dade County. The outflow boundary should drift northward amid modest ambient flow (generally 5-10-kt surface winds), but also, may maximize low-level shear/vorticity locally. The air mass to its north remains unfavorable, per modified 12Z MFL RAOB, but the modified/proximity KEY sounding showed a layer of steep low/middle-level lapse rates and greater moisture content that has supported the activity then not far to its north through southwest. Veering of flow just above the surface limits hodograph size somewhat; however, 100-200 J/kg effective SRH and 40-50-kt effective-shear magnitudes still have been evident along and south of the boundary. ..Edwards.. 02/05/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...KEY... LAT...LON 25488086 25598029 25518013 25058039 24738093 24568151 24558170 24738163 24848143 24848121 24788110 24898084 25028060 25188049 25118068 25168090 25488086 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 AM CST Mon Feb 05 2024 Valid 051300Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE FLORIDA KEYS AND A SMALL PART OF SOUTH FLORIDA... ...SUMMARY... Isolated severe thunderstorms are expected over parts of south Florida and the Keys today, with a marginal tornado, damaging-gust and large-hail threat. ...Synopsis... The synoptic pattern in mid/upper levels will remain highly amplified through the period, but will become more progressive again. A fairly well-stacked, cold-core cyclone now over the southeastern AL/FL Panhandle region is expected to pivot southeastward over the northeastern Gulf to central FL through 00Z, then eastward over the Atlantic tonight. This will occur as an upstream closed 500-mb high over the upper Mississippi Valley weakens and transitions into the northeastern part of a larger- scale, open-wave ridge. Meanwhile, a north/south-elongated cyclone now near the central/ northern Pacific Coast will drift eastward and become an open-wave trough. In the preceding southwesterly to southerly flow aloft, numerous small vorticity lobes and shortwaves will eject across the West Coast States, northern Rockies, Intermountain region, and Great Basin. By 12Z tomorrow, the main trough should extend over the Cascades, southward over the SFO area and Pacific, well offshore from Baja. At the surface, 11Z analysis showed a low near AAF, with cold front arching southeastward then southward over the northeastern/extreme east-central Gulf. The low should track southeastward across the northeastern Gulf, then eastward over south-central FL through 00Z, with the front to its southeast. An outflow boundary from earlier convection was evident over the Upper Keys, and may shift northward into southernmost portions of the mainland before being overtaken by the front and/or prefrontal convection. ...South FL and Keys... In the westerlies aloft, south of the stacked cyclone, a weak shortwave trough was evident in moisture-channel imagery over the extreme eastern Gulf, approaching south FL and the Keys. The feature has been preceded by a band of thunderstorms with an embedded supercell. The related plume of large-scale ascent will shift eastward across the outlook area through midafternoon, supporting both the eastward shift of existing convection across the area, and the development of additional thunderstorms from Atlantic coastal areas of south FL southwestward across the Keys and adjoining waters. Deep shear and long low-level hodographs will persist across the region, beneath tight midlevel height gradient related to the cyclone. Some progs suggest localized backing of near-surface winds along coastal/convective boundaries -- such as apparent now over parts of the upper Keys and Miami-Dade County north of the outflow boundary -- can persist into a period of low-level destabilization related to both muted diabatic heating and warm advection. The thermodynamic environment -- initially hostile for surface-based parcels over mainland areas per 12Z MFL RAOB, but somewhat more favorably modified in the Keys as sampled by the KEY sounding -- also should improve through cooling aloft and steepening of midlevel lapse rates. Accordingly modified forecast soundings yield MLCAPE peaking in the 500-800 J/kg range over the Keys, and around 300-500 J/kg over the southeasternmost mainland. While climatologically small for severe over FL, this buoyancy (given the favorable wind profiles and cold air aloft) will support a threat for relatively low-topped supercells and small bows, accompanied by hail and gusts near severe limits, and the possibility of a tornado where storm-scale/boundary processes can augment low-level shear locally. ..Edwards/Leitman.. 02/05/2024 Read more