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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0103 AM CST Mon Nov 27 2023 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... ...Synopsis... An amplified mid/upper-level ridge will move slowly eastward across the western CONUS, maintaining surface high pressure over the Intermountain West. This pattern will continue to support an enhanced offshore pressure gradient over southern California. Over portions of Ventura and Los Angeles Counties, a belt of breezy/gusty east-northeasterly surface winds will overlap 15-25 percent minimum RH. While locally elevated fire-weather conditions are possible here, recent rainfall and a marginal overlap of the strongest winds and low RH should limit the overall threat. Elsewhere across the CONUS, fire-weather concerns are minimal owing to cool and/or moist surface conditions. ..Weinman.. 11/27/2023 ...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 0103 AM CST Mon Nov 27 2023 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... ...Synopsis... An amplified mid/upper-level ridge will move slowly eastward across the western CONUS, maintaining surface high pressure over the Intermountain West. This pattern will continue to support an enhanced offshore pressure gradient over southern California. Over portions of Ventura and Los Angeles Counties, a belt of breezy/gusty east-northeasterly surface winds will overlap 15-25 percent minimum RH. While locally elevated fire-weather conditions are possible here, recent rainfall and a marginal overlap of the strongest winds and low RH should limit the overall threat. Elsewhere across the CONUS, fire-weather concerns are minimal owing to cool and/or moist surface conditions. ..Weinman.. 11/27/2023 ...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 0103 AM CST Mon Nov 27 2023 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... ...Synopsis... An amplified mid/upper-level ridge will move slowly eastward across the western CONUS, maintaining surface high pressure over the Intermountain West. This pattern will continue to support an enhanced offshore pressure gradient over southern California. Over portions of Ventura and Los Angeles Counties, a belt of breezy/gusty east-northeasterly surface winds will overlap 15-25 percent minimum RH. While locally elevated fire-weather conditions are possible here, recent rainfall and a marginal overlap of the strongest winds and low RH should limit the overall threat. Elsewhere across the CONUS, fire-weather concerns are minimal owing to cool and/or moist surface conditions. ..Weinman.. 11/27/2023 ...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 0103 AM CST Mon Nov 27 2023 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... ...Synopsis... An amplified mid/upper-level ridge will move slowly eastward across the western CONUS, maintaining surface high pressure over the Intermountain West. This pattern will continue to support an enhanced offshore pressure gradient over southern California. Over portions of Ventura and Los Angeles Counties, a belt of breezy/gusty east-northeasterly surface winds will overlap 15-25 percent minimum RH. While locally elevated fire-weather conditions are possible here, recent rainfall and a marginal overlap of the strongest winds and low RH should limit the overall threat. Elsewhere across the CONUS, fire-weather concerns are minimal owing to cool and/or moist surface conditions. ..Weinman.. 11/27/2023 ...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 1225 AM CST Mon Nov 27 2023 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated weak thunderstorms may approach coastal northern California into Wednesday morning. Severe storms are unlikely. ...Synopsis and Discussion... On Tuesday, a large but progressive upper trough will move from the Great Lakes across the Northeast, with rapid height rises on the back side of the trough. Cool air aloft will exist over the lower Great Lakes early in the day, and a rogue lightning flash cannot be ruled out. However, veering low-level winds and decreasing surface convergence suggest less than 10% coverage. To the west, a shortwave trough will affect the West Coast overnight, with cool air aloft into northern CA by 12Z Wednesday. Convergence along an associated cold front and large-scale ascent may result in 100-200 J/kg MUCAPE beneath the upper trough, with lighting possibly over land prior to 12Z Wednesday. Severe weather is unlikely given weak and elevated instability. ..Jewell.. 11/27/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 AM CST Mon Nov 27 2023 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated weak thunderstorms may approach coastal northern California into Wednesday morning. Severe storms are unlikely. ...Synopsis and Discussion... On Tuesday, a large but progressive upper trough will move from the Great Lakes across the Northeast, with rapid height rises on the back side of the trough. Cool air aloft will exist over the lower Great Lakes early in the day, and a rogue lightning flash cannot be ruled out. However, veering low-level winds and decreasing surface convergence suggest less than 10% coverage. To the west, a shortwave trough will affect the West Coast overnight, with cool air aloft into northern CA by 12Z Wednesday. Convergence along an associated cold front and large-scale ascent may result in 100-200 J/kg MUCAPE beneath the upper trough, with lighting possibly over land prior to 12Z Wednesday. Severe weather is unlikely given weak and elevated instability. ..Jewell.. 11/27/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 AM CST Mon Nov 27 2023 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated weak thunderstorms may approach coastal northern California into Wednesday morning. Severe storms are unlikely. ...Synopsis and Discussion... On Tuesday, a large but progressive upper trough will move from the Great Lakes across the Northeast, with rapid height rises on the back side of the trough. Cool air aloft will exist over the lower Great Lakes early in the day, and a rogue lightning flash cannot be ruled out. However, veering low-level winds and decreasing surface convergence suggest less than 10% coverage. To the west, a shortwave trough will affect the West Coast overnight, with cool air aloft into northern CA by 12Z Wednesday. Convergence along an associated cold front and large-scale ascent may result in 100-200 J/kg MUCAPE beneath the upper trough, with lighting possibly over land prior to 12Z Wednesday. Severe weather is unlikely given weak and elevated instability. ..Jewell.. 11/27/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 AM CST Mon Nov 27 2023 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated weak thunderstorms may approach coastal northern California into Wednesday morning. Severe storms are unlikely. ...Synopsis and Discussion... On Tuesday, a large but progressive upper trough will move from the Great Lakes across the Northeast, with rapid height rises on the back side of the trough. Cool air aloft will exist over the lower Great Lakes early in the day, and a rogue lightning flash cannot be ruled out. However, veering low-level winds and decreasing surface convergence suggest less than 10% coverage. To the west, a shortwave trough will affect the West Coast overnight, with cool air aloft into northern CA by 12Z Wednesday. Convergence along an associated cold front and large-scale ascent may result in 100-200 J/kg MUCAPE beneath the upper trough, with lighting possibly over land prior to 12Z Wednesday. Severe weather is unlikely given weak and elevated instability. ..Jewell.. 11/27/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sun Nov 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. today, although some lightning is possible in developing bands of snow across parts of the upper into lower Great Lakes vicinity by tonight. ...Synopsis... Split westerlies emanating from the mid-latitude Pacific continue to converge east of the Rockies, where some further amplification of northern branch large-scale troughing is possible, toward the southern mid latitudes. As this troughing slowly shifts east of the Mississippi Valley, through the Canadian Maritimes and waters offshore of the Atlantic Seaboard, at least some suppression of mid-level heights is forecast on the northern periphery of subtropical ridging centered over the Caribbean. Beneath this regime, a significant cold front, trailing a deepening occluded surface cyclone migrating to the east and northeast of James Bay, is forecast to advance into the Bahamas, northwest Caribbean and southwestern Gulf of Mexico before stalling. In its wake, generally dry/stable conditions will be maintained across much of the U.S. into 12Z Tuesday. ...Lake Superior into lower Great Lakes... While stronger mid-level height falls (associated with a pair of short wave perturbations embedded within the larger-scale cyclonic flow), spread eastward and northeastward, away from the Great Lakes region, models indicate that another consolidating short wave perturbation will dig southeast of the Upper Midwest through the upper Ohio Valley/Mid Atlantic by late Monday night. As it does, deep-layer cyclonic flow likely will be maintained across much of Lake Superior through the lower Great Lakes vicinity, where the southeastward advecting lower/mid-tropospheric cold core (including -20 to -24C around 700 mb) will contribute to steepening lapse rates above the relatively warm lake waters. Associated destabilization is forecast to support developing bands of snow, with forecast soundings indicating the evolution of thermodynamic profiles which could potentially become conducive to lightning, particularly by tonight across and to the immediate lee of the lower Great Lakes. ..Kerr/Weinman.. 11/27/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sun Nov 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. today, although some lightning is possible in developing bands of snow across parts of the upper into lower Great Lakes vicinity by tonight. ...Synopsis... Split westerlies emanating from the mid-latitude Pacific continue to converge east of the Rockies, where some further amplification of northern branch large-scale troughing is possible, toward the southern mid latitudes. As this troughing slowly shifts east of the Mississippi Valley, through the Canadian Maritimes and waters offshore of the Atlantic Seaboard, at least some suppression of mid-level heights is forecast on the northern periphery of subtropical ridging centered over the Caribbean. Beneath this regime, a significant cold front, trailing a deepening occluded surface cyclone migrating to the east and northeast of James Bay, is forecast to advance into the Bahamas, northwest Caribbean and southwestern Gulf of Mexico before stalling. In its wake, generally dry/stable conditions will be maintained across much of the U.S. into 12Z Tuesday. ...Lake Superior into lower Great Lakes... While stronger mid-level height falls (associated with a pair of short wave perturbations embedded within the larger-scale cyclonic flow), spread eastward and northeastward, away from the Great Lakes region, models indicate that another consolidating short wave perturbation will dig southeast of the Upper Midwest through the upper Ohio Valley/Mid Atlantic by late Monday night. As it does, deep-layer cyclonic flow likely will be maintained across much of Lake Superior through the lower Great Lakes vicinity, where the southeastward advecting lower/mid-tropospheric cold core (including -20 to -24C around 700 mb) will contribute to steepening lapse rates above the relatively warm lake waters. Associated destabilization is forecast to support developing bands of snow, with forecast soundings indicating the evolution of thermodynamic profiles which could potentially become conducive to lightning, particularly by tonight across and to the immediate lee of the lower Great Lakes. ..Kerr/Weinman.. 11/27/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sun Nov 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. today, although some lightning is possible in developing bands of snow across parts of the upper into lower Great Lakes vicinity by tonight. ...Synopsis... Split westerlies emanating from the mid-latitude Pacific continue to converge east of the Rockies, where some further amplification of northern branch large-scale troughing is possible, toward the southern mid latitudes. As this troughing slowly shifts east of the Mississippi Valley, through the Canadian Maritimes and waters offshore of the Atlantic Seaboard, at least some suppression of mid-level heights is forecast on the northern periphery of subtropical ridging centered over the Caribbean. Beneath this regime, a significant cold front, trailing a deepening occluded surface cyclone migrating to the east and northeast of James Bay, is forecast to advance into the Bahamas, northwest Caribbean and southwestern Gulf of Mexico before stalling. In its wake, generally dry/stable conditions will be maintained across much of the U.S. into 12Z Tuesday. ...Lake Superior into lower Great Lakes... While stronger mid-level height falls (associated with a pair of short wave perturbations embedded within the larger-scale cyclonic flow), spread eastward and northeastward, away from the Great Lakes region, models indicate that another consolidating short wave perturbation will dig southeast of the Upper Midwest through the upper Ohio Valley/Mid Atlantic by late Monday night. As it does, deep-layer cyclonic flow likely will be maintained across much of Lake Superior through the lower Great Lakes vicinity, where the southeastward advecting lower/mid-tropospheric cold core (including -20 to -24C around 700 mb) will contribute to steepening lapse rates above the relatively warm lake waters. Associated destabilization is forecast to support developing bands of snow, with forecast soundings indicating the evolution of thermodynamic profiles which could potentially become conducive to lightning, particularly by tonight across and to the immediate lee of the lower Great Lakes. ..Kerr/Weinman.. 11/27/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sun Nov 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. today, although some lightning is possible in developing bands of snow across parts of the upper into lower Great Lakes vicinity by tonight. ...Synopsis... Split westerlies emanating from the mid-latitude Pacific continue to converge east of the Rockies, where some further amplification of northern branch large-scale troughing is possible, toward the southern mid latitudes. As this troughing slowly shifts east of the Mississippi Valley, through the Canadian Maritimes and waters offshore of the Atlantic Seaboard, at least some suppression of mid-level heights is forecast on the northern periphery of subtropical ridging centered over the Caribbean. Beneath this regime, a significant cold front, trailing a deepening occluded surface cyclone migrating to the east and northeast of James Bay, is forecast to advance into the Bahamas, northwest Caribbean and southwestern Gulf of Mexico before stalling. In its wake, generally dry/stable conditions will be maintained across much of the U.S. into 12Z Tuesday. ...Lake Superior into lower Great Lakes... While stronger mid-level height falls (associated with a pair of short wave perturbations embedded within the larger-scale cyclonic flow), spread eastward and northeastward, away from the Great Lakes region, models indicate that another consolidating short wave perturbation will dig southeast of the Upper Midwest through the upper Ohio Valley/Mid Atlantic by late Monday night. As it does, deep-layer cyclonic flow likely will be maintained across much of Lake Superior through the lower Great Lakes vicinity, where the southeastward advecting lower/mid-tropospheric cold core (including -20 to -24C around 700 mb) will contribute to steepening lapse rates above the relatively warm lake waters. Associated destabilization is forecast to support developing bands of snow, with forecast soundings indicating the evolution of thermodynamic profiles which could potentially become conducive to lightning, particularly by tonight across and to the immediate lee of the lower Great Lakes. ..Kerr/Weinman.. 11/27/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Sun Nov 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. today, although some lightning is possible in developing bands of snow across parts of the upper into lower Great Lakes vicinity by tonight. ...Synopsis... Split westerlies emanating from the mid-latitude Pacific continue to converge east of the Rockies, where some further amplification of northern branch large-scale troughing is possible, toward the southern mid latitudes. As this troughing slowly shifts east of the Mississippi Valley, through the Canadian Maritimes and waters offshore of the Atlantic Seaboard, at least some suppression of mid-level heights is forecast on the northern periphery of subtropical ridging centered over the Caribbean. Beneath this regime, a significant cold front, trailing a deepening occluded surface cyclone migrating to the east and northeast of James Bay, is forecast to advance into the Bahamas, northwest Caribbean and southwestern Gulf of Mexico before stalling. In its wake, generally dry/stable conditions will be maintained across much of the U.S. into 12Z Tuesday. ...Lake Superior into lower Great Lakes... While stronger mid-level height falls (associated with a pair of short wave perturbations embedded within the larger-scale cyclonic flow), spread eastward and northeastward, away from the Great Lakes region, models indicate that another consolidating short wave perturbation will dig southeast of the Upper Midwest through the upper Ohio Valley/Mid Atlantic by late Monday night. As it does, deep-layer cyclonic flow likely will be maintained across much of Lake Superior through the lower Great Lakes vicinity, where the southeastward advecting lower/mid-tropospheric cold core (including -20 to -24C around 700 mb) will contribute to steepening lapse rates above the relatively warm lake waters. Associated destabilization is forecast to support developing bands of snow, with forecast soundings indicating the evolution of thermodynamic profiles which could potentially become conducive to lightning, particularly by tonight across and to the immediate lee of the lower Great Lakes. ..Kerr/Weinman.. 11/27/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Sun Nov 26 2023 Valid 270100Z - 271200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across the U.S. through tonight. ...01Z Update... While a primary surface cyclone slowly deepens northeast of the upper Great Lakes, toward James Bay, a more compact secondary low is forecast to modestly deepen while migrating northward from the northern Mid Atlantic coast vicinity into New England overnight. A weaker trailing frontal low is now beginning to redevelop east-northeast of the northern Florida coast. Substantive pre-frontal low-level moisture return remains confined to areas offshore of the south Atlantic coast. While further north-northeastward advection of this moisture is probable overnight, it appears that this will remain well east of the northern Atlantic Seaboard, as the cold front advances offshore, in the wake of the low migrating into New England. Due to the initially limited low-level moisture return, and the lack of stronger cooling aloft (which is still focused across the Great Lakes into Ohio Valley vicinity), the development of thermodynamic profiles conducive to convection capable of producing lightning appears unlikely tonight across northern Mid Atlantic coastal areas, southern New England and adjacent coastal waters. ..Kerr.. 11/27/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Sun Nov 26 2023 Valid 270100Z - 271200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across the U.S. through tonight. ...01Z Update... While a primary surface cyclone slowly deepens northeast of the upper Great Lakes, toward James Bay, a more compact secondary low is forecast to modestly deepen while migrating northward from the northern Mid Atlantic coast vicinity into New England overnight. A weaker trailing frontal low is now beginning to redevelop east-northeast of the northern Florida coast. Substantive pre-frontal low-level moisture return remains confined to areas offshore of the south Atlantic coast. While further north-northeastward advection of this moisture is probable overnight, it appears that this will remain well east of the northern Atlantic Seaboard, as the cold front advances offshore, in the wake of the low migrating into New England. Due to the initially limited low-level moisture return, and the lack of stronger cooling aloft (which is still focused across the Great Lakes into Ohio Valley vicinity), the development of thermodynamic profiles conducive to convection capable of producing lightning appears unlikely tonight across northern Mid Atlantic coastal areas, southern New England and adjacent coastal waters. ..Kerr.. 11/27/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Sun Nov 26 2023 Valid 270100Z - 271200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across the U.S. through tonight. ...01Z Update... While a primary surface cyclone slowly deepens northeast of the upper Great Lakes, toward James Bay, a more compact secondary low is forecast to modestly deepen while migrating northward from the northern Mid Atlantic coast vicinity into New England overnight. A weaker trailing frontal low is now beginning to redevelop east-northeast of the northern Florida coast. Substantive pre-frontal low-level moisture return remains confined to areas offshore of the south Atlantic coast. While further north-northeastward advection of this moisture is probable overnight, it appears that this will remain well east of the northern Atlantic Seaboard, as the cold front advances offshore, in the wake of the low migrating into New England. Due to the initially limited low-level moisture return, and the lack of stronger cooling aloft (which is still focused across the Great Lakes into Ohio Valley vicinity), the development of thermodynamic profiles conducive to convection capable of producing lightning appears unlikely tonight across northern Mid Atlantic coastal areas, southern New England and adjacent coastal waters. ..Kerr.. 11/27/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Sun Nov 26 2023 Valid 270100Z - 271200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across the U.S. through tonight. ...01Z Update... While a primary surface cyclone slowly deepens northeast of the upper Great Lakes, toward James Bay, a more compact secondary low is forecast to modestly deepen while migrating northward from the northern Mid Atlantic coast vicinity into New England overnight. A weaker trailing frontal low is now beginning to redevelop east-northeast of the northern Florida coast. Substantive pre-frontal low-level moisture return remains confined to areas offshore of the south Atlantic coast. While further north-northeastward advection of this moisture is probable overnight, it appears that this will remain well east of the northern Atlantic Seaboard, as the cold front advances offshore, in the wake of the low migrating into New England. Due to the initially limited low-level moisture return, and the lack of stronger cooling aloft (which is still focused across the Great Lakes into Ohio Valley vicinity), the development of thermodynamic profiles conducive to convection capable of producing lightning appears unlikely tonight across northern Mid Atlantic coastal areas, southern New England and adjacent coastal waters. ..Kerr.. 11/27/2023 Read more

No watches are valid as of Sun Nov 26 22:20:02 UTC 2023.

No Mesoscale Discussions are in effect as of Sun Nov 26 22:20:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0331 PM CST Sun Nov 26 2023 Valid 281200Z - 041200Z Multiple mid-level troughs are poised to overspread the CONUS through the week, with surface high pressure and associated cool conditions prevailing over most of the U.S. through at least Day 4/Wednesday. By Day 5/Thursday, surface cyclone development is likely across the southern Plains, shifting eastward as the weekend approaches, resulting in wet conditions. Thereafter, a moist low-level airmass will reside across the southeast quadrant of the U.S. while cool and dry conditions prevail through most of the rest of the CONUS. With the exception of localized, brief wildfire conditions possible with dry downslope flow along the High Plains, no significant wildfire-spread potential appears evident over the U.S. this week. ..Squitieri.. 11/26/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more