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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Thu Nov 28 2024 Valid 281300Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST U.S.... ...SUMMARY... A few strong to potentially severe thunderstorms are possible today across parts of the Southeast. ...Synopsis... In mid/upper levels, a couple slow-moving cyclones -- over SK and the James Bay region of eastern Canada -- will anchor a broad area of cyclonic flow that will cover most of the CONUS east of the Rockies. Embedded within that flow belt is a positively tilted shortwave trough, evident in moisture-channel imagery from southern OH to the Ozarks. Today, this feature should move quickly eastward and northeastward while elongating, and should extend from New England to the Delmarva Peninsula and NC/VA border region by 00Z, before ejecting offshore. At the surface, a cold front was drawn at 11Z from western WV over northwestern GA, central AL, southern MS, southwestern LA, and TC coastal shelf waters to deep south TX. This front should proceed eastward and southeastward today, reaching a 00Z position near an HSE-CHS-TLH line and southwestward across the Gulf. By the end of the period, the front should be offshore from all but central FL. ...Southeastern CONUS... An ongoing band of convection, with widely scattered to scattered embedded thunderstorms, was noted mainly ahead of the cold front, from western SC to southern MS. This activity should proceed eastward over the outlook area through the day, with isolated damaging gusts, hail near severe limits possible. A brief tornado or two may occur, conditional on storm-scale processes and local convective interactions. The shortwave trough and associated DCVA will remain north of the outlook area and behind the surface cold front, substantially limiting large-scale support outside very subtle height falls that may extend southward to near a MGM-MCN-CHS line. With the strongest isallobaric forcing located well north/northeast of the area (and moving away), warm-sector surface winds that are not already west- southwesterly should veer that way with time, limiting low-level convergence/lift. This casts considerable uncertainty on convective coverage and duration -- especially in the free warm sector. However, sufficiently strong midlevel flow will remain to yield favorable deep speed shear for any activity that can mature enough to take advantage. Lengthy low-level hodographs with some curvature should remain ahead of the front, even as the hodographs as a whole veer clockwise with respect to the origin. This should yield 100- 200 J/kg SRH in the lowest km, and effective SRH increasing from south to north, with peak values near 300 J/kg. Peak/preconvective MLCAPE should reach 1000-1500 J/kg from the Gulf Coast to parts of SC, diminishing northeastward substantially from there. The overall severe threat should diminish this evening and tonight as lift and instability both weaken, and the hodograph-stretching LLJ pulls away across Atlantic waters. ..Edwards/Leitman.. 11/28/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Thu Nov 28 2024 Valid 281300Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST U.S.... ...SUMMARY... A few strong to potentially severe thunderstorms are possible today across parts of the Southeast. ...Synopsis... In mid/upper levels, a couple slow-moving cyclones -- over SK and the James Bay region of eastern Canada -- will anchor a broad area of cyclonic flow that will cover most of the CONUS east of the Rockies. Embedded within that flow belt is a positively tilted shortwave trough, evident in moisture-channel imagery from southern OH to the Ozarks. Today, this feature should move quickly eastward and northeastward while elongating, and should extend from New England to the Delmarva Peninsula and NC/VA border region by 00Z, before ejecting offshore. At the surface, a cold front was drawn at 11Z from western WV over northwestern GA, central AL, southern MS, southwestern LA, and TC coastal shelf waters to deep south TX. This front should proceed eastward and southeastward today, reaching a 00Z position near an HSE-CHS-TLH line and southwestward across the Gulf. By the end of the period, the front should be offshore from all but central FL. ...Southeastern CONUS... An ongoing band of convection, with widely scattered to scattered embedded thunderstorms, was noted mainly ahead of the cold front, from western SC to southern MS. This activity should proceed eastward over the outlook area through the day, with isolated damaging gusts, hail near severe limits possible. A brief tornado or two may occur, conditional on storm-scale processes and local convective interactions. The shortwave trough and associated DCVA will remain north of the outlook area and behind the surface cold front, substantially limiting large-scale support outside very subtle height falls that may extend southward to near a MGM-MCN-CHS line. With the strongest isallobaric forcing located well north/northeast of the area (and moving away), warm-sector surface winds that are not already west- southwesterly should veer that way with time, limiting low-level convergence/lift. This casts considerable uncertainty on convective coverage and duration -- especially in the free warm sector. However, sufficiently strong midlevel flow will remain to yield favorable deep speed shear for any activity that can mature enough to take advantage. Lengthy low-level hodographs with some curvature should remain ahead of the front, even as the hodographs as a whole veer clockwise with respect to the origin. This should yield 100- 200 J/kg SRH in the lowest km, and effective SRH increasing from south to north, with peak values near 300 J/kg. Peak/preconvective MLCAPE should reach 1000-1500 J/kg from the Gulf Coast to parts of SC, diminishing northeastward substantially from there. The overall severe threat should diminish this evening and tonight as lift and instability both weaken, and the hodograph-stretching LLJ pulls away across Atlantic waters. ..Edwards/Leitman.. 11/28/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0306 AM CST Thu Nov 28 2024 Valid 011200Z - 061200Z ...DISCUSSION... Organized severe-thunderstorm potential still appears low through most of the extended range. A deep upper-level trough is expected to persist across the central/eastern CONUS into at least the middle of next week, as multiple reinforcing shortwaves move southeastward out of Canada. In conjunction with this trough, surface ridging will persist across the Gulf of Mexico and generally maintain dry and stable conditions for most of the CONUS. Farther west, a slow-moving mid/upper-level trough may gradually amplify and potentially become a cut off low in the vicinity of the Desert Southwest into northwest Mexico and Baja California. Guidance does suggest that gradual low-level moisture return will be possible across parts of TX/LA from D4/Sunday into early next week, as the surface ridge shifts eastward. This moisture return could result in occasional thunderstorm potential within a weak warm-advection regime, though the synoptic pattern is expected to remain unfavorable for an organized severe threat. By mid week, predictability regarding the synoptic pattern substantially decreases, especially regarding if/when the potential cut-off low begins to eject eastward across the Southwest and southern Rockies. A faster ejection could result in some possibility for more-organized convection across the southern Plains by late next week, though the bulk of guidance still suggests generally low potential through at least D7/Wednesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0306 AM CST Thu Nov 28 2024 Valid 011200Z - 061200Z ...DISCUSSION... Organized severe-thunderstorm potential still appears low through most of the extended range. A deep upper-level trough is expected to persist across the central/eastern CONUS into at least the middle of next week, as multiple reinforcing shortwaves move southeastward out of Canada. In conjunction with this trough, surface ridging will persist across the Gulf of Mexico and generally maintain dry and stable conditions for most of the CONUS. Farther west, a slow-moving mid/upper-level trough may gradually amplify and potentially become a cut off low in the vicinity of the Desert Southwest into northwest Mexico and Baja California. Guidance does suggest that gradual low-level moisture return will be possible across parts of TX/LA from D4/Sunday into early next week, as the surface ridge shifts eastward. This moisture return could result in occasional thunderstorm potential within a weak warm-advection regime, though the synoptic pattern is expected to remain unfavorable for an organized severe threat. By mid week, predictability regarding the synoptic pattern substantially decreases, especially regarding if/when the potential cut-off low begins to eject eastward across the Southwest and southern Rockies. A faster ejection could result in some possibility for more-organized convection across the southern Plains by late next week, though the bulk of guidance still suggests generally low potential through at least D7/Wednesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0306 AM CST Thu Nov 28 2024 Valid 011200Z - 061200Z ...DISCUSSION... Organized severe-thunderstorm potential still appears low through most of the extended range. A deep upper-level trough is expected to persist across the central/eastern CONUS into at least the middle of next week, as multiple reinforcing shortwaves move southeastward out of Canada. In conjunction with this trough, surface ridging will persist across the Gulf of Mexico and generally maintain dry and stable conditions for most of the CONUS. Farther west, a slow-moving mid/upper-level trough may gradually amplify and potentially become a cut off low in the vicinity of the Desert Southwest into northwest Mexico and Baja California. Guidance does suggest that gradual low-level moisture return will be possible across parts of TX/LA from D4/Sunday into early next week, as the surface ridge shifts eastward. This moisture return could result in occasional thunderstorm potential within a weak warm-advection regime, though the synoptic pattern is expected to remain unfavorable for an organized severe threat. By mid week, predictability regarding the synoptic pattern substantially decreases, especially regarding if/when the potential cut-off low begins to eject eastward across the Southwest and southern Rockies. A faster ejection could result in some possibility for more-organized convection across the southern Plains by late next week, though the bulk of guidance still suggests generally low potential through at least D7/Wednesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0306 AM CST Thu Nov 28 2024 Valid 011200Z - 061200Z ...DISCUSSION... Organized severe-thunderstorm potential still appears low through most of the extended range. A deep upper-level trough is expected to persist across the central/eastern CONUS into at least the middle of next week, as multiple reinforcing shortwaves move southeastward out of Canada. In conjunction with this trough, surface ridging will persist across the Gulf of Mexico and generally maintain dry and stable conditions for most of the CONUS. Farther west, a slow-moving mid/upper-level trough may gradually amplify and potentially become a cut off low in the vicinity of the Desert Southwest into northwest Mexico and Baja California. Guidance does suggest that gradual low-level moisture return will be possible across parts of TX/LA from D4/Sunday into early next week, as the surface ridge shifts eastward. This moisture return could result in occasional thunderstorm potential within a weak warm-advection regime, though the synoptic pattern is expected to remain unfavorable for an organized severe threat. By mid week, predictability regarding the synoptic pattern substantially decreases, especially regarding if/when the potential cut-off low begins to eject eastward across the Southwest and southern Rockies. A faster ejection could result in some possibility for more-organized convection across the southern Plains by late next week, though the bulk of guidance still suggests generally low potential through at least D7/Wednesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0306 AM CST Thu Nov 28 2024 Valid 011200Z - 061200Z ...DISCUSSION... Organized severe-thunderstorm potential still appears low through most of the extended range. A deep upper-level trough is expected to persist across the central/eastern CONUS into at least the middle of next week, as multiple reinforcing shortwaves move southeastward out of Canada. In conjunction with this trough, surface ridging will persist across the Gulf of Mexico and generally maintain dry and stable conditions for most of the CONUS. Farther west, a slow-moving mid/upper-level trough may gradually amplify and potentially become a cut off low in the vicinity of the Desert Southwest into northwest Mexico and Baja California. Guidance does suggest that gradual low-level moisture return will be possible across parts of TX/LA from D4/Sunday into early next week, as the surface ridge shifts eastward. This moisture return could result in occasional thunderstorm potential within a weak warm-advection regime, though the synoptic pattern is expected to remain unfavorable for an organized severe threat. By mid week, predictability regarding the synoptic pattern substantially decreases, especially regarding if/when the potential cut-off low begins to eject eastward across the Southwest and southern Rockies. A faster ejection could result in some possibility for more-organized convection across the southern Plains by late next week, though the bulk of guidance still suggests generally low potential through at least D7/Wednesday. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Thu Nov 28 2024 Valid 301200Z - 011200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm potential appears low on Saturday. ...Synopsis... A deep mid/upper-level trough will persist over the central/eastern CONUS on Saturday. An upper-level ridge will extend from the Southwest into the Pacific Northwest, while a weak mid/upper-level trough will begin to approach the California coast. In the wake of a cold front, an expansive surface ridge will maintain generally dry/stable conditions across the CONUS, with limited thunderstorm potential. Cold temperatures aloft will continue to support lake-effect snow bands across the Great Lakes, and isolated lightning flashes cannot be ruled out with the strongest bands. Some low-level moisture return may commence into Deep South TX, but inland deep convection appears unlikely in the absence of stronger buoyancy and large-scale ascent. Farther west, the 00Z NAM is an outlier in developing modest elevated buoyancy across southern CA in advance of the approaching upper trough, while other guidance currently suggests little appreciable thunderstorm potential in this area. ..Dean.. 11/28/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Thu Nov 28 2024 Valid 301200Z - 011200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm potential appears low on Saturday. ...Synopsis... A deep mid/upper-level trough will persist over the central/eastern CONUS on Saturday. An upper-level ridge will extend from the Southwest into the Pacific Northwest, while a weak mid/upper-level trough will begin to approach the California coast. In the wake of a cold front, an expansive surface ridge will maintain generally dry/stable conditions across the CONUS, with limited thunderstorm potential. Cold temperatures aloft will continue to support lake-effect snow bands across the Great Lakes, and isolated lightning flashes cannot be ruled out with the strongest bands. Some low-level moisture return may commence into Deep South TX, but inland deep convection appears unlikely in the absence of stronger buoyancy and large-scale ascent. Farther west, the 00Z NAM is an outlier in developing modest elevated buoyancy across southern CA in advance of the approaching upper trough, while other guidance currently suggests little appreciable thunderstorm potential in this area. ..Dean.. 11/28/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Thu Nov 28 2024 Valid 301200Z - 011200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm potential appears low on Saturday. ...Synopsis... A deep mid/upper-level trough will persist over the central/eastern CONUS on Saturday. An upper-level ridge will extend from the Southwest into the Pacific Northwest, while a weak mid/upper-level trough will begin to approach the California coast. In the wake of a cold front, an expansive surface ridge will maintain generally dry/stable conditions across the CONUS, with limited thunderstorm potential. Cold temperatures aloft will continue to support lake-effect snow bands across the Great Lakes, and isolated lightning flashes cannot be ruled out with the strongest bands. Some low-level moisture return may commence into Deep South TX, but inland deep convection appears unlikely in the absence of stronger buoyancy and large-scale ascent. Farther west, the 00Z NAM is an outlier in developing modest elevated buoyancy across southern CA in advance of the approaching upper trough, while other guidance currently suggests little appreciable thunderstorm potential in this area. ..Dean.. 11/28/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Thu Nov 28 2024 Valid 301200Z - 011200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm potential appears low on Saturday. ...Synopsis... A deep mid/upper-level trough will persist over the central/eastern CONUS on Saturday. An upper-level ridge will extend from the Southwest into the Pacific Northwest, while a weak mid/upper-level trough will begin to approach the California coast. In the wake of a cold front, an expansive surface ridge will maintain generally dry/stable conditions across the CONUS, with limited thunderstorm potential. Cold temperatures aloft will continue to support lake-effect snow bands across the Great Lakes, and isolated lightning flashes cannot be ruled out with the strongest bands. Some low-level moisture return may commence into Deep South TX, but inland deep convection appears unlikely in the absence of stronger buoyancy and large-scale ascent. Farther west, the 00Z NAM is an outlier in developing modest elevated buoyancy across southern CA in advance of the approaching upper trough, while other guidance currently suggests little appreciable thunderstorm potential in this area. ..Dean.. 11/28/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Thu Nov 28 2024 Valid 301200Z - 011200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm potential appears low on Saturday. ...Synopsis... A deep mid/upper-level trough will persist over the central/eastern CONUS on Saturday. An upper-level ridge will extend from the Southwest into the Pacific Northwest, while a weak mid/upper-level trough will begin to approach the California coast. In the wake of a cold front, an expansive surface ridge will maintain generally dry/stable conditions across the CONUS, with limited thunderstorm potential. Cold temperatures aloft will continue to support lake-effect snow bands across the Great Lakes, and isolated lightning flashes cannot be ruled out with the strongest bands. Some low-level moisture return may commence into Deep South TX, but inland deep convection appears unlikely in the absence of stronger buoyancy and large-scale ascent. Farther west, the 00Z NAM is an outlier in developing modest elevated buoyancy across southern CA in advance of the approaching upper trough, while other guidance currently suggests little appreciable thunderstorm potential in this area. ..Dean.. 11/28/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CST Thu Nov 28 2024 Valid 291200Z - 301200Z ...NO CRITICAL AREAS... ...Synopsis... Surface high pressure will continue to support cooler temperatures across most of the CONUS as broad upper-level troughing persists through tomorrow (Friday). Quiescent fire weather conditions are expected over most areas. The surface pressure gradient over southern California may relax somewhat through the day. As such, any offshore-driven fire weather conditions should remain constrained to very localized, terrain-favoring areas for brief periods of time. The brief and localized nature of these conditions precludes fire weather highlights this outlook. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 291200Z - 301200Z ...NO CRITICAL AREAS... ...Synopsis... Surface high pressure will continue to support cooler temperatures across most of the CONUS as broad upper-level troughing persists through tomorrow (Friday). Quiescent fire weather conditions are expected over most areas. The surface pressure gradient over southern California may relax somewhat through the day. As such, any offshore-driven fire weather conditions should remain constrained to very localized, terrain-favoring areas for brief periods of time. The brief and localized nature of these conditions precludes fire weather highlights this outlook. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 291200Z - 301200Z ...NO CRITICAL AREAS... ...Synopsis... Surface high pressure will continue to support cooler temperatures across most of the CONUS as broad upper-level troughing persists through tomorrow (Friday). Quiescent fire weather conditions are expected over most areas. The surface pressure gradient over southern California may relax somewhat through the day. As such, any offshore-driven fire weather conditions should remain constrained to very localized, terrain-favoring areas for brief periods of time. The brief and localized nature of these conditions precludes fire weather highlights this outlook. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 291200Z - 301200Z ...NO CRITICAL AREAS... ...Synopsis... Surface high pressure will continue to support cooler temperatures across most of the CONUS as broad upper-level troughing persists through tomorrow (Friday). Quiescent fire weather conditions are expected over most areas. The surface pressure gradient over southern California may relax somewhat through the day. As such, any offshore-driven fire weather conditions should remain constrained to very localized, terrain-favoring areas for brief periods of time. The brief and localized nature of these conditions precludes fire weather highlights this outlook. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 281200Z - 291200Z ...Synopsis... Broad mid-level troughing, along with surface high pressure and associated cooler temperatures, will envelop most of the CONUS today, leading to quiescent fire weather conditions over most locales. The one exception will be the Ventura Valley in California, where Elevated fire weather conditions are expected. A surface pressure gradient over southern California, driven by high pressure to the east, will encourage offshore flow, consisting of 15+ mph sustained winds amid 15-20 percent RH. Given modestly dry fuels over the region, Elevated highlights appear warranted. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 281200Z - 291200Z ...Synopsis... Broad mid-level troughing, along with surface high pressure and associated cooler temperatures, will envelop most of the CONUS today, leading to quiescent fire weather conditions over most locales. The one exception will be the Ventura Valley in California, where Elevated fire weather conditions are expected. A surface pressure gradient over southern California, driven by high pressure to the east, will encourage offshore flow, consisting of 15+ mph sustained winds amid 15-20 percent RH. Given modestly dry fuels over the region, Elevated highlights appear warranted. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 281200Z - 291200Z ...Synopsis... Broad mid-level troughing, along with surface high pressure and associated cooler temperatures, will envelop most of the CONUS today, leading to quiescent fire weather conditions over most locales. The one exception will be the Ventura Valley in California, where Elevated fire weather conditions are expected. A surface pressure gradient over southern California, driven by high pressure to the east, will encourage offshore flow, consisting of 15+ mph sustained winds amid 15-20 percent RH. Given modestly dry fuels over the region, Elevated highlights appear warranted. ..Squitieri.. 11/28/2024 ...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 0137 AM CST Thu Nov 28 2024 Valid 281200Z - 291200Z ...Synopsis... Broad mid-level troughing, along with surface high pressure and associated cooler temperatures, will envelop most of the CONUS today, leading to quiescent fire weather conditions over most locales. The one exception will be the Ventura Valley in California, where Elevated fire weather conditions are expected. A surface pressure gradient over southern California, driven by high pressure to the east, will encourage offshore flow, consisting of 15+ mph sustained winds amid 15-20 percent RH. Given modestly dry fuels over the region, Elevated highlights appear warranted. ..Squitieri.. 11/28/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more