SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook CORR 1 NWS Storm Prediction Center Norman OK 0308 PM CST Wed Nov 06 2024 Valid 081200Z - 141200Z CORRECTED FOR WORDING A mid-level trough will overspread the Plains states this weekend and rapidly eject into the Northeast by early next week. At the same time, another mid-level trough will amplify while impinging on the West Coast and overspreading the Interior West by the end of the period. With this upper-air pattern, multiple instances of surface cyclone development are likely over the central U.S., which will encourage low-level moisture return and ample precipitation accumulations between the Rockies and Appalachians. Meanwhile surface high pressure will persist over the Interior/Inter-Mountain West. The net result will be relatively quiescent fire weather conditions across much of the U.S., away from coastal areas through the middle of next week. Some wildfire-spread concerns will exist for portions of the Mid-Atlantic for Days 3-4 (Friday), after a cold front passes the region. By Friday afternoon, 15+ mph sustained westerly surface winds will coincide with 30-40 percent RH for at least a few hours. 40% Critical highlights have been introduced for Day 3/Friday given how dry the fuels are, and given that meaningful precipitation accumulations are unlikely through at least the rest of the week. Medium-range guidance depicts weaker surface wind fields over the weekend (hence no Critical probabilities introduced), though dry low-level conditions may promote at least localized wildfire-spread potential. Medium-range guidance also hints at potentially dry offshore flow across southern California by the middle of next week. Low-end Critical probabilities may be needed in later outlooks pending guidance consensus and consistency in this scenario in medium-range guidance over the next few days. ..Squitieri.. 11/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0142 PM CST Wed Nov 06 2024 Valid 062000Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE FLORIDA KEYS... ...SUMMARY... A couple of brief tornadoes will be possible within outermost fringes of the circulation of Hurricane Rafael, through this evening, across the Keys and the far southwestern Florida Peninsula. ...20Z Update... No changes are required to the prior outlook. See the previous discussion and MD #2214 for additional details. ..Wendt.. 11/06/2024 .PREV DISCUSSION... /ISSUED 1028 AM CST Wed Nov 06 2024/ ...South Florida and the Keys... Hurricane Rafael will track toward/across western Cuba tonight. Model guidance continues to trend toward weaker low-level wind fields over south FL and shunting the risk southwestward/offshore. Will maintain the ongoing risk areas as CAM solutions show a few discrete cells in the outer bands of the system later this afternoon and evening. However, the overall risk appears to be lessening. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0128 PM CST Wed Nov 06 2024 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH-CENTRAL TO NORTH TX... ...SUMMARY... Isolated severe thunderstorms are possible through early evening Friday across parts of south-central to north Texas. ...Texas... A deep mid/upper-level cyclone is forecast to move north-northeastward from NM into the central High Plains on Friday. A surface low will move northward from the TX Panhandle vicinity into southwest KS, as a trailing outflow-reinforced cold front moves through parts of TX/OK. A surface ridge initially covering parts of the Plains and Midwest will tend to shift eastward with time, though the lingering influence of this ridge will tend to limit the northern extent of more substantial moisture return. Extensive convection will likely be ongoing Friday morning across parts of west TX/OK. An isolated severe threat could accompany the storms along the southern periphery of ongoing convection during the morning, where somewhat more favorable instability will be in place. Uncertainties remain regarding the northward extent of substantial destabilization through the day. However, sufficient low-level and deep-layer shear will support potential for organized cells/clusters with at least an isolated severe threat. This threat could spread northeastward across parts of central/north TX through the day, before a likely weakening trend during the evening as stronger large-scale ascent lifts away from the warm sector. A minor expansion to the Marginal Risk has been made across parts of TX based on the latest guidance, though uncertainty remains high regarding the eastern and northern extent of the organized severe threat, as well as the location of any corridors where a somewhat greater threat could evolve. ..Dean.. 11/06/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0128 PM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF VENTURA AND LOS ANGELES COUNTIES IN SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 11/06/2024 .PREV DISCUSSION... /ISSUED 0200 AM CST Wed Nov 06 2024/ ...Synopsis... On the backside of a deep/closed midlevel low over the Southwest, strong deep-layer northerly flow will persist across southern CA -- downstream of an amplified large-scale ridge over the West Coast. This upper-level pattern will maintain an expansive surface anticyclone over the Intermountain West, with a related tight offshore pressure gradient and Santa Ana winds across southern CA. ...Southern California... While the offshore pressure gradient will be gradually weakening across southern CA (compared to Day 1/Wednesday), LAX-DAG should still be around -5 mb from Thursday morning through Thursday afternoon -- a strong indicator of continued critical fire-weather conditions. High-resolution guidance is in good agreement, depicting a continuation of 20+ mph sustained northeasterly surface winds (with gusts upwards of 50 mph) and lower teens to single-digit RH. The best overlap and longest duration of these conditions is once again expected across the wind-prone corridor of northern Los Angeles and southern Ventura Counties, where Critical highlights are in place. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2214 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR THE FLORIDA KEYS
Mesoscale Discussion 2214 NWS Storm Prediction Center Norman OK 0105 PM CST Wed Nov 06 2024 Areas affected...the Florida Keys Concerning...Severe potential...Watch unlikely Valid 061905Z - 062100Z Probability of Watch Issuance...20 percent SUMMARY...A brief waterspout/onshore tornado will be possible this afternoon within showery convection on the outer/northern periphery of Hurricane Rafael. Watch issuance will likely remain unnecessary. DISCUSSION...Recent radar reflectivity loop from KBYX (Key West WSR-88D) continues to depict a very loosely organized band of convection/showers moving west-northwestward on the northern fringe of Rafael, whose center remains just south of western Cuba at this time. A few of the showers have exhibited weak/rather transient low-level rotation over the past several hours. With low-level flow quasi-unidirectional/westerly, but increasing in magnitude with height, low-level shear is sufficient to support continued/weak rotation within stronger convective elements. Overall however, given the weak/brief nature of the circulations that should remain the case this afternoon, and thus no more than a weak/brief spout or tornado expected, a tornado watch is not anticipated. ..Goss/Hart.. 11/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...KEY... LAT...LON 24758288 24678188 24858116 24788096 24598100 24458177 24498288 24638300 24758288 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF WEST TX... ...SUMMARY... Severe thunderstorms are possible across parts of west and central Texas, with the greatest threat expected Thursday evening/night across parts of west Texas. Large hail, isolated severe gusts, and a tornado or two are all possible. ...Parts of west and central TX... A deep mid/upper-level low is forecast to move slowly eastward across AZ/NM on Thursday, before accelerating later Thursday night into early Friday morning. An expansive surface ridge will initially cover much of the western/central CONUS, though weak cyclogenesis is expected later in the period in the vicinity of an inverted surface trough over west TX. Seasonably rich surface moisture will stream westward across parts of western/central TX through the day, with increasing moisture also expected atop a relatively shallow cool/stable layer into parts of northwest TX and southwest OK by the end of the period. Elevated convection will be possible near/north of the effective warm front through the day, with isolated diurnal storm development also possible within the moistening/destabilizing warm sector. Storm coverage and the organized severe threat are expected to increase later in the evening into the overnight hours, as the low-level jet nocturnally intensifies and the mid/upper-level low approaches the region. Moderate instability and rather strong deep-layer shear will support the potential for a few supercells and organized clusters, especially across parts of the Permian Basin and Edwards Plateau regions. A threat for large hail and localized severe gusts will accompany the strongest storms. Also, while the bulk of the nocturnal convection may tend to be somewhat elevated, increasingly rich low-level moisture will support some potential for surface-based supercells near the surface trough/low, with favorably veering wind profiles supporting a threat of a tornado or two. ...Lower FL Keys... Hurricane Rafael is forecast to move westward across the southern Gulf of Mexico on Thursday; see NHC forecasts and advisories for more information. Relatively strong low-level flow to the east of Rafael may still be in place across the lower Keys at the start of the forecast period, though weakening is expected through the day as Rafael moves away from the region. While a low-probability tornado threat cannot be ruled out across parts of the lower Keys, the magnitude of the threat from 12Z onward appears too limited for probabilities at this time. ..Dean.. 11/06/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1037 AM CST Wed Nov 06 2024 Valid 061700Z - 071200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF VENTURA AND LOS ANGELES COUNTIES... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA... Current observations show strong offshore flow across terrain-favoring areas surrounding the Los Angeles metropolitan area, with sustained 30+ mph winds (and gusts well exceeding 60 mph) amid RH near 15 percent in the Ventura Valley region. These conditions should persist through much of the afternoon, necessitating the maintenance of Extremely Critical highlights. Observations in higher-terrain areas around Los Angeles toward the Laguna Mountains show solidly Critical conditions ongoing, with 20+ mph sustained winds and gusts exceeding 45 mph coinciding with 15-20 percent RH. These conditions should continue to the end of the period. Finally, guidance consensus continues to show Elevated conditions across the northern California Valley region, where downslope flow will encourage 15-20 mph sustained northerly winds amid 15-20 percent RH through the period. ..Squitieri.. 11/06/2024 .PREV DISCUSSION... /ISSUED 0200 AM CST Wed Nov 06 2024/ ...Synopsis... Between a highly amplified large-scale ridge over the West Coast, and a deep midlevel trough extending from the northern Plains into the Four Corners, a belt of strong deep-layer northerly flow will overspread the Great Basin into southern CA. In response, an expansive surface anticyclone will be reinforced over the Intermountain West. These factors will yield a strong offshore pressure gradient and ample upper-level support across southern CA, leading to a strong Santa Ana wind event. ...Southern California... From Wednesday morning into Wednesday night, the tightening offshore pressure gradient (LAX-DAG peaking around -7 to -8 mb), coupled with the strong deep-layer north-northeasterly flow directed toward the coast, will favor sustained northeasterly surface winds of 30+ mph and gusts upwards of 60 mph across much of southern CA. Higher gusts (70+ mph) are expected over the wind-prone mountains and slopes. These strong/gusty winds will combine with lower teens/single-digit RH, leading to dangerous fire-weather conditions. The most volatile and long-duration combination of strong winds and low RH over receptive fuels is expected over the wind-prone Santa Ana corridor of southern Ventura and northern Los Angeles Counties -- where Extremely Critical fire-weather conditions are expected. ...Northern/Central California... The tight pressure gradient peripheral to the strong surface anticyclone and enhanced deep-layer northerly flow will also favor strong northerly surface winds amid low RH over the western Sacramento Valley to the coast. Given modestly receptive fuels across this region, elevated to locally critical fire-weather conditions are expected from Wednesday morning into Wednesday night. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Wed Nov 06 2024 Valid 061630Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER THE LOWER FLORIDA KEYS... ...SUMMARY... A couple of brief tornadoes will be possible within outermost fringes of the circulation of Hurricane Rafael, through this evening, across the Keys and the far southwestern Florida Peninsula. ...South Florida and the Keys... Hurricane Rafael will track toward/across western Cuba tonight. Model guidance continues to trend toward weaker low-level wind fields over south FL and shunting the risk southwestward/offshore. Will maintain the ongoing risk areas as CAM solutions show a few discrete cells in the outer bands of the system later this afternoon and evening. However, the overall risk appears to be lessening. ..Hart/Smith.. 11/06/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CST Wed Nov 06 2024 Valid 061300Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE LOWER FLORIDA KEYS... ...SUMMARY... A couple of brief tornadoes will be possible within outermost fringes of the circulation of Hurricane Rafael, from late morning into the evening, across the Keys and the far southwestern Florida Peninsula. ...Synopsis... In mid/upper levels, mean troughing will remain over the Rocky Mountain States as a strong subsynoptic trough -- now evident in moisture-channel imagery over the Four Corners region -- strengthens to a closed cyclone. The associate 500-mb low is expected to become better-developed throughout the period as it closes off and retrogrades south-southwestward across AZ. In response to these developments, height rises are forecast across the southern Plains and Gulf Coast region, while ridging also builds westward from the Bermuda high. In turn, this should shift Hurricane Rafael westward toward the central Gulf, following today's crossing of western Cuba, per NHC forecast. At the surface, 11Z analysis showed a frontal-wave low over ON north of Lake Huron, with cold front across Lower MI, IN, western parts of KY/TN/MS, central LA, and the shelf waters off the TX Gulf Coast. Under height rises and weakening/largely parallel flow aloft, the frontal segment south of about I-40 should become quasistationary through the remainder of the period. Given those factors, weak midlevel lapse rates, and negligible mid/upper support, associated thunderstorms should have an unconditional severe potential below 5% for gusts and less than 2% for tornado, with no large-hail threat. ...FL Keys and vicinity... Although Rafael will be pivoting more westward away from the region than previous forecast cycles suggested, and is a relatively small hurricane, the influence of ambient shear imparts a northeastward tilt to the overall convective pattern. This will lead to the passage of peripheral cells and perhaps (over the Lower Keys) banding features. The track forecast also should result in the largest low-level shear remaining west and south of EYW, but still-favorable hodographs passing across the outlook area from this afternoon into tonight. As such, the outlook lines are shifted slightly westward, in keeping with NHC track-forecast trends, but still kept at 5% "slight" levels over the Lower Keys for this cycle. See latest NHC advisories for forecast track/intensity of Rafael, and tropical-related watches/warnings. ..Edwards/Mosier.. 11/06/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0337 AM CST Wed Nov 06 2024 Valid 091200Z - 141200Z ...DISCUSSION... Modest severe potential remains apparent during parts of the extended period. A mid/upper low over the central High Plains at 12Z Saturday should pivot northeastward towards the Upper Midwest as it becomes an open wave. A belt of strong mid-level southwesterlies should overlap with the northwestern periphery of a modified low-level moisture plume emanating north from the western Gulf. This plume is expected to be narrower to the north-northwest of the Ark-La-Tex. Combined with probable ongoing convection in the warm conveyor ahead of the weak surface front, the overall severe threat on D4 should be confined/low-end. While outlier guidance indicates the possibility of TC Rafael approaching the coastal LA vicinity this weekend, ensemble trends and latest NHC forecast suggest it will probably remain over the western Gulf. Guidance consensus still indicates an amplified upper trough should progress into the West early next week, with this feature reaching the central states mid-week. This may eventually overlap a broadening warm/moist sector emanating north from the western Gulf across the south-central states. But poor run-to-run continuity and large ensemble spread persist with the evolution of this trough. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 AM CST Wed Nov 06 2024 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH-CENTRAL TO NORTH TX... ...SUMMARY... Isolated severe thunderstorms are possible through early evening Friday across parts of south-central to north Texas. ...TX... A mid/upper low should deepen as it moves from the central NM vicinity to the central High Plains. A belt of fast mid-level flow will largely remain within the southeast arc of this cyclone. At the surface, a minor low over west TX should similarly advance north towards western KS. A cold front will arc to its south in mainly a north-south orientation through central portions of TX. Linear clusters of convection will likely be ongoing at 12Z Friday across parts of west TX near the surface cyclone. This activity will probably persist through the day, especially with northern extent where activity should largely remain elevated. This will limit surface-based destabilization north, with more prominent surface heating probable from central TX southward. Guidance differs on just how far north instability will develop. This yields uncertainty on the demarcation of the low-probability severe area where low-level to deep-layer shear will be strong. Given the north-northeast track of the upper low and associated weak surface cyclone, forcing for ascent should wane towards late day along the south-central TX portion of the front. Progressively weaker low-level shear indicates more of a hail/wind threat from central TX south. Overall setup suggests severe coverage should remain isolated into the afternoon and likely diminish after sunset. ..Grams.. 11/06/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 AM CST Wed Nov 06 2024 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH-CENTRAL TO NORTH TX... ...SUMMARY... Isolated severe thunderstorms are possible through early evening Friday across parts of south-central to north Texas. ...TX... A mid/upper low should deepen as it moves from the central NM vicinity to the central High Plains. A belt of fast mid-level flow will largely remain within the southeast arc of this cyclone. At the surface, a minor low over west TX should similarly advance north towards western KS. A cold front will arc to its south in mainly a north-south orientation through central portions of TX. Linear clusters of convection will likely be ongoing at 12Z Friday across parts of west TX near the surface cyclone. This activity will probably persist through the day, especially with northern extent where activity should largely remain elevated. This will limit surface-based destabilization north, with more prominent surface heating probable from central TX southward. Guidance differs on just how far north instability will develop. This yields uncertainty on the demarcation of the low-probability severe area where low-level to deep-layer shear will be strong. Given the north-northeast track of the upper low and associated weak surface cyclone, forcing for ascent should wane towards late day along the south-central TX portion of the front. Progressively weaker low-level shear indicates more of a hail/wind threat from central TX south. Overall setup suggests severe coverage should remain isolated into the afternoon and likely diminish after sunset. ..Grams.. 11/06/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHERN LOS ANGELES AND SOUTHERN VENTURA COUNTIES... ...Synopsis... On the backside of a deep/closed midlevel low over the Southwest, strong deep-layer northerly flow will persist across southern CA -- downstream of an amplified large-scale ridge over the West Coast. This upper-level pattern will maintain an expansive surface anticyclone over the Intermountain West, with a related tight offshore pressure gradient and Santa Ana winds across southern CA. ...Southern California... While the offshore pressure gradient will be gradually weakening across southern CA (compared to Day 1/Wednesday), LAX-DAG should still be around -5 mb from Thursday morning through Thursday afternoon -- a strong indicator of continued critical fire-weather conditions. High-resolution guidance is in good agreement, depicting a continuation of 20+ mph sustained northeasterly surface winds (with gusts upwards of 50 mph) and lower teens to single-digit RH. The best overlap and longest duration of these conditions is once again expected across the wind-prone corridor of northern Los Angeles and southern Ventura Counties, where Critical highlights are in place. ..Weinman.. 11/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHERN LOS ANGELES AND SOUTHERN VENTURA COUNTIES... ...Synopsis... On the backside of a deep/closed midlevel low over the Southwest, strong deep-layer northerly flow will persist across southern CA -- downstream of an amplified large-scale ridge over the West Coast. This upper-level pattern will maintain an expansive surface anticyclone over the Intermountain West, with a related tight offshore pressure gradient and Santa Ana winds across southern CA. ...Southern California... While the offshore pressure gradient will be gradually weakening across southern CA (compared to Day 1/Wednesday), LAX-DAG should still be around -5 mb from Thursday morning through Thursday afternoon -- a strong indicator of continued critical fire-weather conditions. High-resolution guidance is in good agreement, depicting a continuation of 20+ mph sustained northeasterly surface winds (with gusts upwards of 50 mph) and lower teens to single-digit RH. The best overlap and longest duration of these conditions is once again expected across the wind-prone corridor of northern Los Angeles and southern Ventura Counties, where Critical highlights are in place. ..Weinman.. 11/06/2024 ...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 0200 AM CST Wed Nov 06 2024 Valid 061200Z - 071200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR NORTHERN LOS ANGELES AND SOUTHERN VENTURA COUNTIES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... ...Synopsis... Between a highly amplified large-scale ridge over the West Coast, and a deep midlevel trough extending from the northern Plains into the Four Corners, a belt of strong deep-layer northerly flow will overspread the Great Basin into southern CA. In response, an expansive surface anticyclone will be reinforced over the Intermountain West. These factors will yield a strong offshore pressure gradient and ample upper-level support across southern CA, leading to a strong Santa Ana wind event. ...Southern California... From Wednesday morning into Wednesday night, the tightening offshore pressure gradient (LAX-DAG peaking around -7 to -8 mb), coupled with the strong deep-layer north-northeasterly flow directed toward the coast, will favor sustained northeasterly surface winds of 30+ mph and gusts upwards of 60 mph across much of southern CA. Higher gusts (70+ mph) are expected over the wind-prone mountains and slopes. These strong/gusty winds will combine with lower teens/single-digit RH, leading to dangerous fire-weather conditions. The most volatile and long-duration combination of strong winds and low RH over receptive fuels is expected over the wind-prone Santa Ana corridor of southern Ventura and northern Los Angeles Counties -- where Extremely Critical fire-weather conditions are expected. ...Northern/Central California... The tight pressure gradient peripheral to the strong surface anticyclone and enhanced deep-layer northerly flow will also favor strong northerly surface winds amid low RH over the western Sacramento Valley to the coast. Given modestly receptive fuels across this region, elevated to locally critical fire-weather conditions are expected from Wednesday morning into Wednesday night. ..Weinman.. 11/06/2024 ...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 0200 AM CST Wed Nov 06 2024 Valid 061200Z - 071200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR NORTHERN LOS ANGELES AND SOUTHERN VENTURA COUNTIES... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... ...Synopsis... Between a highly amplified large-scale ridge over the West Coast, and a deep midlevel trough extending from the northern Plains into the Four Corners, a belt of strong deep-layer northerly flow will overspread the Great Basin into southern CA. In response, an expansive surface anticyclone will be reinforced over the Intermountain West. These factors will yield a strong offshore pressure gradient and ample upper-level support across southern CA, leading to a strong Santa Ana wind event. ...Southern California... From Wednesday morning into Wednesday night, the tightening offshore pressure gradient (LAX-DAG peaking around -7 to -8 mb), coupled with the strong deep-layer north-northeasterly flow directed toward the coast, will favor sustained northeasterly surface winds of 30+ mph and gusts upwards of 60 mph across much of southern CA. Higher gusts (70+ mph) are expected over the wind-prone mountains and slopes. These strong/gusty winds will combine with lower teens/single-digit RH, leading to dangerous fire-weather conditions. The most volatile and long-duration combination of strong winds and low RH over receptive fuels is expected over the wind-prone Santa Ana corridor of southern Ventura and northern Los Angeles Counties -- where Extremely Critical fire-weather conditions are expected. ...Northern/Central California... The tight pressure gradient peripheral to the strong surface anticyclone and enhanced deep-layer northerly flow will also favor strong northerly surface winds amid low RH over the western Sacramento Valley to the coast. Given modestly receptive fuels across this region, elevated to locally critical fire-weather conditions are expected from Wednesday morning into Wednesday night. ..Weinman.. 11/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN A PART OF WEST TX... ...SUMMARY... Isolated severe thunderstorms are possible, beginning in the late afternoon Thursday across parts of west and central Texas. The most likely corridor for large hail will be over a part of west Texas on Thursday evening/night. ...West/central TX... A mid/upper low will drift east across AZ/NM through much of the day Thursday. By Thursday night, it should accelerate as an attendant mid-level jet becomes confined to the southeast quadrant of the cyclone. While a surface ridge will initially nose down the southern High Plains from an anticyclone over the central High Plains, this will eventually lose amplitude. Weak cyclogenesis should occur late in the period along an inverted surface trough in parts of west TX. A persistent increase in low-level moisture from the western Gulf will return northwestward through the period. While some elevated convection will be possible during the day, initially from central to northwest TX, the bulk of convective development should occur in the evening/night as the low-level jet broadly intensifies. This will be coincident with a gradual increase in mid-level height falls overspreading west TX Thursday night. A mesoscale corridor of relatively greater supercell potential appears evident during the evening/night. This appears centered on parts of the Lower Pecos Valley/Permian Basin and the western Edwards Plateau regions near the surface trough. While low-level lapse rates should be weak, strong southwesterly speed shear in the mid to upper levels will be favorable for a primary threat of large hail with a mix of cells/small clusters. An abrupt cutoff to surface-based severe convection is expected to the north/west of this corridor, especially as weak cyclogenesis occurs. While consistency has increased in guidance relative to 24 hours, where exactly this demarcation is will likely be modulated by how widespread elevated convection becomes during the evening to night. ..Grams.. 11/06/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CST Wed Nov 06 2024 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN A PART OF WEST TX... ...SUMMARY... Isolated severe thunderstorms are possible, beginning in the late afternoon Thursday across parts of west and central Texas. The most likely corridor for large hail will be over a part of west Texas on Thursday evening/night. ...West/central TX... A mid/upper low will drift east across AZ/NM through much of the day Thursday. By Thursday night, it should accelerate as an attendant mid-level jet becomes confined to the southeast quadrant of the cyclone. While a surface ridge will initially nose down the southern High Plains from an anticyclone over the central High Plains, this will eventually lose amplitude. Weak cyclogenesis should occur late in the period along an inverted surface trough in parts of west TX. A persistent increase in low-level moisture from the western Gulf will return northwestward through the period. While some elevated convection will be possible during the day, initially from central to northwest TX, the bulk of convective development should occur in the evening/night as the low-level jet broadly intensifies. This will be coincident with a gradual increase in mid-level height falls overspreading west TX Thursday night. A mesoscale corridor of relatively greater supercell potential appears evident during the evening/night. This appears centered on parts of the Lower Pecos Valley/Permian Basin and the western Edwards Plateau regions near the surface trough. While low-level lapse rates should be weak, strong southwesterly speed shear in the mid to upper levels will be favorable for a primary threat of large hail with a mix of cells/small clusters. An abrupt cutoff to surface-based severe convection is expected to the north/west of this corridor, especially as weak cyclogenesis occurs. While consistency has increased in guidance relative to 24 hours, where exactly this demarcation is will likely be modulated by how widespread elevated convection becomes during the evening to night. ..Grams.. 11/06/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 PM CST Tue Nov 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE KEYS AND PORTIONS OF EXTREME SOUTHERN FLORIDA... ...SUMMARY... A couple of brief tornadoes will be possible within outer bands of Hurricane Rafael, from late morning into the evening, across the Keys and the far southern Peninsula of Florida. ...Hurricane Rafael... Dominant Bermuda High will prove instrumental in the upcoming track of Hurricane Rafael. Over the next 36hr, Rafael is forecast to continue its northwest trajectory across Cuba into the southeastern Gulf Basin. Low-level shear will gradually increase across the Keys into extreme southern FL, and outer convective bands will begin to affect this portion of FL, especially later this afternoon/evening. Current track (reference https://www.nhc.noaa.gov) suggests severe probabilities will not need to be expanded north across the Peninsula as strongest shear will remain offshore across the Gulf Basin. Some tornado threat can be expected with strongest, more organized convection, especially across the Keys. ..Darrow/Weinman.. 11/06/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 PM CST Tue Nov 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE KEYS AND PORTIONS OF EXTREME SOUTHERN FLORIDA... ...SUMMARY... A couple of brief tornadoes will be possible within outer bands of Hurricane Rafael, from late morning into the evening, across the Keys and the far southern Peninsula of Florida. ...Hurricane Rafael... Dominant Bermuda High will prove instrumental in the upcoming track of Hurricane Rafael. Over the next 36hr, Rafael is forecast to continue its northwest trajectory across Cuba into the southeastern Gulf Basin. Low-level shear will gradually increase across the Keys into extreme southern FL, and outer convective bands will begin to affect this portion of FL, especially later this afternoon/evening. Current track (reference https://www.nhc.noaa.gov) suggests severe probabilities will not need to be expanded north across the Peninsula as strongest shear will remain offshore across the Gulf Basin. Some tornado threat can be expected with strongest, more organized convection, especially across the Keys. ..Darrow/Weinman.. 11/06/2024 Read more