Storm Prediction Center

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1045 AM CST Wed Dec 24 2025 Valid 241700Z - 251200Z Dry, downslope flow commencing across the southern High Plains is still expected to bring elevated fire weather conditions to eastern NM, TX/OK Panhandles, southeastern CO and far southwest KS through this afternoon. Upper-level cloud cover should inhibit optimal boundary layer mixing, limiting southwesterly winds to around 15 mph at the surface through the afternoon. Despite cloud cover, very warm temperatures in the 70s and lower 80s under pronounced upper-level ridging will result in minimum relative humidity of 15-20%. These meteorological conditions combined with dry fuels supports an elevated fire weather threat with only minor changes to existing Elevated highlights. ..Williams.. 12/24/2025 .PREV DISCUSSION... /ISSUED 1233 AM CST Wed Dec 24 2025/ ...Synopsis... An upper ridge will prevail over the central U.S. while a mid-level trough impinges on the Interior West today. Gradual strengthening of the surface lee trough across the Plains will encourage modest dry downslope flow across portions of the southern High Plains this afternoon. 15 mph sustained westerly surface winds amid 15-20 percent RH will overlap with drying fuels over northeastern New Mexico and southeastern Colorado, eastward into far southwestern Kansas and the Texas Panhandle for a few hours this afternoon, warranting Elevated highlights. ...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 1045 AM CST Wed Dec 24 2025 Valid 241700Z - 251200Z Dry, downslope flow commencing across the southern High Plains is still expected to bring elevated fire weather conditions to eastern NM, TX/OK Panhandles, southeastern CO and far southwest KS through this afternoon. Upper-level cloud cover should inhibit optimal boundary layer mixing, limiting southwesterly winds to around 15 mph at the surface through the afternoon. Despite cloud cover, very warm temperatures in the 70s and lower 80s under pronounced upper-level ridging will result in minimum relative humidity of 15-20%. These meteorological conditions combined with dry fuels supports an elevated fire weather threat with only minor changes to existing Elevated highlights. ..Williams.. 12/24/2025 .PREV DISCUSSION... /ISSUED 1233 AM CST Wed Dec 24 2025/ ...Synopsis... An upper ridge will prevail over the central U.S. while a mid-level trough impinges on the Interior West today. Gradual strengthening of the surface lee trough across the Plains will encourage modest dry downslope flow across portions of the southern High Plains this afternoon. 15 mph sustained westerly surface winds amid 15-20 percent RH will overlap with drying fuels over northeastern New Mexico and southeastern Colorado, eastward into far southwestern Kansas and the Texas Panhandle for a few hours this afternoon, warranting Elevated highlights. ...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 1025 AM CST Wed Dec 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF COASTAL CALIFORNIA AND PORTIONS OF THE CENTRAL VALLEY... ...SUMMARY... An isolated risk for severe/damaging gusts and perhaps a brief tornado will exist today into tonight along much of the California Coast and portions of the Central Valley. ...California... A shallow band of pre-frontal convection may continue to pose a threat for locally severe/damaging winds (especially across higher terrain/ridgetops) and perhaps a brief tornado this morning across parts of coastal southern CA. This activity is being supported by strong low-level warm advection and large-scale ascent associated with an enhanced mid/upper-level jet. Current expectations are for this activity to continue moving eastward through the afternoon across the remainder of coastal southern CA in a strongly sheared environment. However, various NAM/RAP forecast soundings across this area suggest that even with low 60s surface dewpoints and modest/filtered daytime heating, the overall severe threat will likely remain isolated due to poor lapse rates aloft and limited boundary-layer instability. Reference Mesoscale Discussion 2269 for more details on the near-term severe threat across southern CA. Additional rounds of convection are expected later this evening and overnight into early Thursday morning over portions of northern/central CA, as multiple mid-level shortwave troughs embedded within persistent large-scale upper troughing over the eastern Pacific overspread these areas. One such shortwave trough is forecast to advance over coastal central CA and vicinity around 25/00-06Z this evening, with cool temperatures aloft (less than -20C at 500 mb) supporting weak MUCAPE. Both low-level and deep-layer shear are expected to gradually increase this evening as the shortwave trough approaches, with some updraft organization possible. Strong to locally severe winds and a brief tornado or two appear possible with this activity, but uncertainty is still substantial whether sufficient instability will be present to support surface-based thunderstorms. A stronger mid-level shortwave trough will move east-northeastward from the eastern Pacific and approach the northern CA Coast by 12Z Thursday morning, along with a deepening surface low and attendant cold front. A 70-80+ kt mid-level jet will accompany this shortwave trough, along with a 50-60 kt south-southwesterly low-level jet. A broken band of low-topped thunderstorms will likely develop in association with this shortwave trough along/ahead of the front, and overspread coastal portions of northern/central CA late tonight through early Thursday morning (25/06-12Z). A strongly sheared environment and weak but sufficient MLCAPE may exist to support at least an isolated threat for severe/damaging winds and a tornado or two as this activity spreads inland through the end of the period. Still, the overall severe threat should be tempered by the lack of stronger instability. Finally, some chance for low-topped/mini supercells may exist late this afternoon/evening across parts of the Central Valley of CA. If these thunderstorms can develop and be sustained, they could pose a threat for both damaging winds and a brief tornado. But, confidence in this scenario occurring remains rather low. ..Gleason/Bunting.. 12/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1025 AM CST Wed Dec 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF COASTAL CALIFORNIA AND PORTIONS OF THE CENTRAL VALLEY... ...SUMMARY... An isolated risk for severe/damaging gusts and perhaps a brief tornado will exist today into tonight along much of the California Coast and portions of the Central Valley. ...California... A shallow band of pre-frontal convection may continue to pose a threat for locally severe/damaging winds (especially across higher terrain/ridgetops) and perhaps a brief tornado this morning across parts of coastal southern CA. This activity is being supported by strong low-level warm advection and large-scale ascent associated with an enhanced mid/upper-level jet. Current expectations are for this activity to continue moving eastward through the afternoon across the remainder of coastal southern CA in a strongly sheared environment. However, various NAM/RAP forecast soundings across this area suggest that even with low 60s surface dewpoints and modest/filtered daytime heating, the overall severe threat will likely remain isolated due to poor lapse rates aloft and limited boundary-layer instability. Reference Mesoscale Discussion 2269 for more details on the near-term severe threat across southern CA. Additional rounds of convection are expected later this evening and overnight into early Thursday morning over portions of northern/central CA, as multiple mid-level shortwave troughs embedded within persistent large-scale upper troughing over the eastern Pacific overspread these areas. One such shortwave trough is forecast to advance over coastal central CA and vicinity around 25/00-06Z this evening, with cool temperatures aloft (less than -20C at 500 mb) supporting weak MUCAPE. Both low-level and deep-layer shear are expected to gradually increase this evening as the shortwave trough approaches, with some updraft organization possible. Strong to locally severe winds and a brief tornado or two appear possible with this activity, but uncertainty is still substantial whether sufficient instability will be present to support surface-based thunderstorms. A stronger mid-level shortwave trough will move east-northeastward from the eastern Pacific and approach the northern CA Coast by 12Z Thursday morning, along with a deepening surface low and attendant cold front. A 70-80+ kt mid-level jet will accompany this shortwave trough, along with a 50-60 kt south-southwesterly low-level jet. A broken band of low-topped thunderstorms will likely develop in association with this shortwave trough along/ahead of the front, and overspread coastal portions of northern/central CA late tonight through early Thursday morning (25/06-12Z). A strongly sheared environment and weak but sufficient MLCAPE may exist to support at least an isolated threat for severe/damaging winds and a tornado or two as this activity spreads inland through the end of the period. Still, the overall severe threat should be tempered by the lack of stronger instability. Finally, some chance for low-topped/mini supercells may exist late this afternoon/evening across parts of the Central Valley of CA. If these thunderstorms can develop and be sustained, they could pose a threat for both damaging winds and a brief tornado. But, confidence in this scenario occurring remains rather low. ..Gleason/Bunting.. 12/24/2025 Read more

MD 2269 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST
Mesoscale Discussion 2269 NWS Storm Prediction Center Norman OK 0922 AM CST Wed Dec 24 2025 Areas affected...Portions of the southern California Coast Concerning...Severe potential...Watch unlikely Valid 241522Z - 241715Z Probability of Watch Issuance...5 percent SUMMARY...A brief tornado is possible along the immediate coast as a shallow convective band moves east this morning. DISCUSSION...A shallow band of convection, not currently deep enough to support lightning production, continues to move eastward into the LA Basin region ahead of a strong shortwave trough. The strongest parts of this band remain near the coastline where dewpoints appear to be in the low 60s F. Prior to the passage of this activity, KVTX VAD data did show notable low-level shear/SRH. Recent velocity imagery has also depicted weak, transient areas of low-level rotation. A brief tornado will remain possible as this activity continues east. Strong and gusty winds may also accompany the band. The primary threat area will likely remain along the immediate coast given decreasing surface moisture and buoyancy inland. ..Wendt/Gleason.. 12/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGX...LOX... LAT...LON 33911889 34031895 34311890 34181855 33971821 33781789 33581766 33461763 33411778 33461806 33551816 33911889 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH Read more

MD 2267 CONCERNING HEAVY SNOW FOR PARTS OF SOUTHERN MAINE
Mesoscale Discussion 2267 NWS Storm Prediction Center Norman OK 0447 AM CST Wed Dec 24 2025 Areas affected...Parts of southern Maine Concerning...Heavy snow Valid 241047Z - 241445Z SUMMARY...Band of heavy snow with 1-1.5 in/hr rates to continue across parts of southern Maine through around 14Z. DISCUSSION...Within the left exit region of a robust mid/upper-level jet streak and to the north of a surface low just offshore of coastal Maine, strong low-level frontogenesis and convergence is yielding strong mesoscale and large-scale forcing for ascent over southern Maine. Here, a cold/saturated profile, substantial lift within the DGZ, and light winds within the DGZ will favor a continuation of heavy snowfall rates (around 1-1.5 inches per hour). These heavy rates should continue through around 14Z, before the left-exit region ascent moves offshore. ..Weinman.. 12/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX... LAT...LON 44806982 44676962 44146910 43856918 43596984 43517027 43797059 44297066 44697058 44857027 44806982 Read more

MD 2268 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL/SOUTHERN CALIFORNIA COAST
Mesoscale Discussion 2268 NWS Storm Prediction Center Norman OK 0711 AM CST Wed Dec 24 2025 Areas affected...Central/Southern California Coast Concerning...Severe potential...Watch unlikely Valid 241311Z - 241445Z Probability of Watch Issuance...5 percent SUMMARY...Localized risk for strong to severe gusts and perhaps a brief waterspout/tornado may increase over the next couple hours. DISCUSSION...Radar data from KVBX over the last hour or so depicts a north/south-oriented band of shallow/cellular convection with transient rotation streaming northward across the Channel Islands toward Point Conception. Over the next couple hours, a modest increase in boundary-layer moisture/low-level theta-e toward the immediate coast and localized terrain effects may support some increase in updraft intensity. Despite limited buoyancy, strong deep-layer flow/shear and low-level hodograph curvature (200-300 m2/s2 0-1 km SRH per KVBX/KVTX VWP) may favor a risk of strong to locally damaging gusts and perhaps a brief waterspout/tornado with any sustained surface-based convection that can evolve over the next couple hours. ..Weinman/Smith.. 12/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOX... LAT...LON 34351884 34131872 33981882 34011915 34281951 34331997 34392065 34572066 34692051 34711990 34561925 34351884 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Wed Dec 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA AND THE CENTRAL VALLEY... ...SUMMARY... An isolated risk for localized severe gusts and perhaps a brief tornado will exist today into tonight along much of the California coast and the central valley. ...California... Water-vapor early this morning shows an upper trough over the eastern Pacific with a lead disturbance moving north near the northern coast of CA/southwest OR. Farther south, a mid-level vorticity maximum west of southern CA will move to the Sierra Nevada by early evening. Upstream of this disturbance and farther west, models show a more potent mid-level shortwave trough moving northeast towards the northern CA coast by 25/12z. In the low levels, a notable deepening of a cyclone is forecast tonight over the eastern Pacific to the west of the northern coast of CA. Zone of persistent and strong low-level WAA regime will aid in maintaining a persistent rain shield with shallow convection from Point Conception southward along the coast into the LA Basin this morning. Scant buoyancy will limit updraft vigor/depth, but intense flow (reference KVBX, KVTX WSR-88D VAD data) in the lowest 2-km MSL may enable an isolated risk for wind damage/severe gusts near the coast and in terrain-favored locales. A brief tornado cannot be ruled out, but this threat would likely depend on the development of stronger embedded convective elements within the larger rain shield. Later this afternoon, some convection-allowing models show low-topped convection developing within the central valley in an environment characterized by cold mid-level temperatures and a modestly moist airmass. A mini supercell risk is possible with an attendant isolated threat for a brief tornado and wind. By early evening, another round of low-topped convection is progged to develop west of the coast. This activity will focus from near Point Conception northward along the coast tonight as strengthening ascent accompanies the approach of the next mid-level wave. Elongated hodographs and weak buoyancy will support potential storm organization with the stronger storms and an isolated threat for severe wind gusts/brief tornado. ..Smith/Weinman.. 12/24/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Wed Dec 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA AND THE CENTRAL VALLEY... ...SUMMARY... An isolated risk for localized severe gusts and perhaps a brief tornado will exist today into tonight along much of the California coast and the central valley. ...California... Water-vapor early this morning shows an upper trough over the eastern Pacific with a lead disturbance moving north near the northern coast of CA/southwest OR. Farther south, a mid-level vorticity maximum west of southern CA will move to the Sierra Nevada by early evening. Upstream of this disturbance and farther west, models show a more potent mid-level shortwave trough moving northeast towards the northern CA coast by 25/12z. In the low levels, a notable deepening of a cyclone is forecast tonight over the eastern Pacific to the west of the northern coast of CA. Zone of persistent and strong low-level WAA regime will aid in maintaining a persistent rain shield with shallow convection from Point Conception southward along the coast into the LA Basin this morning. Scant buoyancy will limit updraft vigor/depth, but intense flow (reference KVBX, KVTX WSR-88D VAD data) in the lowest 2-km MSL may enable an isolated risk for wind damage/severe gusts near the coast and in terrain-favored locales. A brief tornado cannot be ruled out, but this threat would likely depend on the development of stronger embedded convective elements within the larger rain shield. Later this afternoon, some convection-allowing models show low-topped convection developing within the central valley in an environment characterized by cold mid-level temperatures and a modestly moist airmass. A mini supercell risk is possible with an attendant isolated threat for a brief tornado and wind. By early evening, another round of low-topped convection is progged to develop west of the coast. This activity will focus from near Point Conception northward along the coast tonight as strengthening ascent accompanies the approach of the next mid-level wave. Elongated hodographs and weak buoyancy will support potential storm organization with the stronger storms and an isolated threat for severe wind gusts/brief tornado. ..Smith/Weinman.. 12/24/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CST Wed Dec 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... This weekend, a mid-level ridge will move from the mid Mississippi Valley eastward to the Atlantic Seaboard, as a trough digs southeastward into the north-central U.S. A moist airmass will advect northeastward into the Ohio and Tennessee Valleys, ahead of a cold front moving through the mid Mississippi Valley. Thunderstorm development, mostly post-frontal in nature, will be possible Sunday afternoon from the Arkansas River Valley northeastward into the Ohio Valley. Although an isolated severe threat may develop, the storms should be elevated and the threat will be limited by weak instability. On Monday, the cold front is forecast to move to the southern Atlantic Seaboard, with a dry and cool airmass residing over much of the nation. This dry airmass is forecast to remain in place through mid-week, keeping the chance for thunderstorms low across the continental U.S. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CST Wed Dec 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... This weekend, a mid-level ridge will move from the mid Mississippi Valley eastward to the Atlantic Seaboard, as a trough digs southeastward into the north-central U.S. A moist airmass will advect northeastward into the Ohio and Tennessee Valleys, ahead of a cold front moving through the mid Mississippi Valley. Thunderstorm development, mostly post-frontal in nature, will be possible Sunday afternoon from the Arkansas River Valley northeastward into the Ohio Valley. Although an isolated severe threat may develop, the storms should be elevated and the threat will be limited by weak instability. On Monday, the cold front is forecast to move to the southern Atlantic Seaboard, with a dry and cool airmass residing over much of the nation. This dry airmass is forecast to remain in place through mid-week, keeping the chance for thunderstorms low across the continental U.S. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CST Wed Dec 24 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe storms are expected to develop across the continental U.S. on Friday or Friday night. ...DISCUSSION... At mid-levels, a ridge will move eastward across the central U.S. on Friday, as a subtle shortwave trough moves into the Northeast. A few storms may form ahead of the trough Friday afternoon and evening across parts of the central Appalachians. Out west, a trough will move inland across the Pacific Northwest, with southwesterly flow being in place across the Intermountain West. Isolated storms will be possible across parts of California and in the Intermountain West. No severe threat is expected to develop Friday or Friday night. ..Broyles.. 12/24/2025 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Wed Dec 24 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL CALIFORNIA COAST... ...SUMMARY... Thunderstorms with potential to produce marginally severe wind gusts and perhaps a brief tornado, will be possible on Thursday along parts of the central California Coast. ...California Coast... A mid-level low and an associated trough over the eastern Pacific will gradually approach the West Coast on Thursday. Ahead of the trough, a stream of moisture will feed into California, where scattered thunderstorms are expected to develop during the day. At the surface, a front is forecast to move southward along the central California coast. To the south of the front near the coast, surface dewpoints will be in the 50s F. In addition, a 50 to 60 knot low-level jet is forecast to be in proximity to the higher surface dewpoints. This feature will create strong low-level shear along the central California coast, where some forecast soundings have curved hodographs and 0-3 km storm-relative helicity above 250 m2/s2. This could support a marginal severe threat, with cells that rotate within short line segments. A brief tornado or isolated severe wind gust will be possible. ..Broyles.. 12/24/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Wed Dec 24 2025 Valid 251200Z - 261200Z ...Synopsis... Upper ridging will persist across the central U.S. to some degree tomorrow (Thursday), though some flattening of this ridge is expected as the West Coast upper trough de-amplifies, with a mid-level impulse poised to overspread the Rockies. As this occurs, a surface low will develop over the central Plains, encouraging locally stronger downslope flow along the central and southern High Plains compared to previous days. 15-20 mph sustained westerly surface winds are likely across much of the High Plains Thursday afternoon. However, the latest guidance depicts relatively higher RH compared to previous days (i.e. 20-30 percent RH across the southern High Plains). Despite the locally higher RH, the persistent curing of fuels and stronger surface wind field suggests that Elevated highlights are warranted. These highlights have been introduced for portions of far eastern New Mexico into the Texas Panhandle, where RH is more likely to drop below 20 percent for at least a few hours tomorrow. ..Squitieri.. 12/24/2025 ...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 1241 AM CST Wed Dec 24 2025 Valid 251200Z - 261200Z ...Synopsis... Upper ridging will persist across the central U.S. to some degree tomorrow (Thursday), though some flattening of this ridge is expected as the West Coast upper trough de-amplifies, with a mid-level impulse poised to overspread the Rockies. As this occurs, a surface low will develop over the central Plains, encouraging locally stronger downslope flow along the central and southern High Plains compared to previous days. 15-20 mph sustained westerly surface winds are likely across much of the High Plains Thursday afternoon. However, the latest guidance depicts relatively higher RH compared to previous days (i.e. 20-30 percent RH across the southern High Plains). Despite the locally higher RH, the persistent curing of fuels and stronger surface wind field suggests that Elevated highlights are warranted. These highlights have been introduced for portions of far eastern New Mexico into the Texas Panhandle, where RH is more likely to drop below 20 percent for at least a few hours tomorrow. ..Squitieri.. 12/24/2025 ...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 1233 AM CST Wed Dec 24 2025 Valid 241200Z - 251200Z ...Synopsis... An upper ridge will prevail over the central U.S. while a mid-level trough impinges on the Interior West today. Gradual strengthening of the surface lee trough across the Plains will encourage modest dry downslope flow across portions of the southern High Plains this afternoon. 15 mph sustained westerly surface winds amid 15-20 percent RH will overlap with drying fuels over northeastern New Mexico and southeastern Colorado, eastward into far southwestern Kansas and the Texas Panhandle for a few hours this afternoon, warranting Elevated highlights. ..Squitieri.. 12/24/2025 ...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 1233 AM CST Wed Dec 24 2025 Valid 241200Z - 251200Z ...Synopsis... An upper ridge will prevail over the central U.S. while a mid-level trough impinges on the Interior West today. Gradual strengthening of the surface lee trough across the Plains will encourage modest dry downslope flow across portions of the southern High Plains this afternoon. 15 mph sustained westerly surface winds amid 15-20 percent RH will overlap with drying fuels over northeastern New Mexico and southeastern Colorado, eastward into far southwestern Kansas and the Texas Panhandle for a few hours this afternoon, warranting Elevated highlights. ..Squitieri.. 12/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1153 PM CST Tue Dec 23 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA AND THE CENTRAL VALLEY... ...SUMMARY... Thunderstorms with marginally severe wind gusts, small hail and potentially a brief tornado will be possible from Wednesday into Wednesday night along parts of the California coast, and inland across the San Joaquin Valley. ... Synopsis ... A high-amplitude midlevel pattern will persist on Wednesday, characterized by a deep trough across the eastern Pacific and a building ridge across the Plains. This pattern will maintain a broad belt of intense cyclonic flow across California into the Interior West. Throughout the day, an initial shortwave trough will continue lifting northeast from the eastern Pacific into the Pacific Northwest, while the attendant surface low lifts more northward along the coast toward Washington. Late on Wednesday a second, more potent trough will approach central and northern California -- primarily after dark. This setup will facilitate a prolonged period rain and embedded thunderstorms across California and portions of the Interior West into Thursday. ... California Coast ... Strong ascent and strengthening onshore flow will aid in modest destabilization Wednesday morning ahead of a surface cold front. An ongoing band of convection is expected across the central and southern coastal areas associated with the strongly forced ascent along the advancing cold front. Given the presence of a strong low-level jet (locally exceeding 50 knots at 1 km AGL), there is a risk that these strong winds will mix to the surface within the strongest convection resulting in damaging wind gusts. Forecast soundings across the area do maintain some low-level curvature ahead of the convective line, such that any convective element able to interact with true surface-based buoyancy would have the potential for a brief tornado. In the wake of the morning convection, a secondary surface low will intensify during the afternoon and overnight as it approaches the northern California coast. This will likely trigger another round or two of broken, low-topped convection along a second cold front. Despite weaker instability than with the morning convection, the strength of the wind fields would suggest an ongoing risk for isolated wind damage as this convection moves inland. ... Central Valley ... Cold midlevel temperatures and increasing height falls will overspread surface dewpoints in the 40s to perhaps low 50s. Although buoyancy will remain modest (MUCAPE at or below 500 J/kg), the presence of a powerful midlevel jet in excess of 100 knots will support long hodographs. This combination of modest instability and large/long hodographs may support a threat for semi-organized convection, including some potential for supercells. The strongest storms will be capable of producing damaging gusts, hail, and a brief tornado before the convection shifts east into the higher terrain and weakens. ..Marsh/Squitieri.. 12/24/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1153 PM CST Tue Dec 23 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA AND THE CENTRAL VALLEY... ...SUMMARY... Thunderstorms with marginally severe wind gusts, small hail and potentially a brief tornado will be possible from Wednesday into Wednesday night along parts of the California coast, and inland across the San Joaquin Valley. ... Synopsis ... A high-amplitude midlevel pattern will persist on Wednesday, characterized by a deep trough across the eastern Pacific and a building ridge across the Plains. This pattern will maintain a broad belt of intense cyclonic flow across California into the Interior West. Throughout the day, an initial shortwave trough will continue lifting northeast from the eastern Pacific into the Pacific Northwest, while the attendant surface low lifts more northward along the coast toward Washington. Late on Wednesday a second, more potent trough will approach central and northern California -- primarily after dark. This setup will facilitate a prolonged period rain and embedded thunderstorms across California and portions of the Interior West into Thursday. ... California Coast ... Strong ascent and strengthening onshore flow will aid in modest destabilization Wednesday morning ahead of a surface cold front. An ongoing band of convection is expected across the central and southern coastal areas associated with the strongly forced ascent along the advancing cold front. Given the presence of a strong low-level jet (locally exceeding 50 knots at 1 km AGL), there is a risk that these strong winds will mix to the surface within the strongest convection resulting in damaging wind gusts. Forecast soundings across the area do maintain some low-level curvature ahead of the convective line, such that any convective element able to interact with true surface-based buoyancy would have the potential for a brief tornado. In the wake of the morning convection, a secondary surface low will intensify during the afternoon and overnight as it approaches the northern California coast. This will likely trigger another round or two of broken, low-topped convection along a second cold front. Despite weaker instability than with the morning convection, the strength of the wind fields would suggest an ongoing risk for isolated wind damage as this convection moves inland. ... Central Valley ... Cold midlevel temperatures and increasing height falls will overspread surface dewpoints in the 40s to perhaps low 50s. Although buoyancy will remain modest (MUCAPE at or below 500 J/kg), the presence of a powerful midlevel jet in excess of 100 knots will support long hodographs. This combination of modest instability and large/long hodographs may support a threat for semi-organized convection, including some potential for supercells. The strongest storms will be capable of producing damaging gusts, hail, and a brief tornado before the convection shifts east into the higher terrain and weakens. ..Marsh/Squitieri.. 12/24/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0653 PM CST Tue Dec 23 2025 Valid 240100Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF COASTAL CALIFORNIA... ...SUMMARY... An isolated threat for severe/damaging gusts and perhaps brief tornadoes may develop late tonight/early Wednesday morning across parts of coastal California. ... 01Z Update ... A strong short-wave trough/surface low continues to approach the California/Oregon coast. Later tonight a midlevel speed max will intensify, helping to deepen the surface low, which will drive a cold front eastward into California during the overnight and morning hours. Despite limited buoyancy, especially surface based, strengthening tropospheric flow and forced convection along the cold front may support isolated damaging wind gusts along the California coast. Should truly surface-based buoyancy develop and the forced convection can realize this buoyancy, forecast wind profiles along the coast exhibit sufficient deep-layer shear and low-level curvature to support brief tornadoes. The easternmost extent of this threat, especially across southern California, is delineated by the expected position of the surface-cold front at 12Z/4AM PT. The threat will continue past 12Z/4AM PT. ..Marsh.. 12/24/2025 Read more