Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0321 AM CST Sun Dec 17 2023 Valid 201200Z - 251200Z ...DISCUSSION... Medium-range guidance is in good agreement that a low-amplitude upper pattern, free of any larger disturbances, and a dry continental air mass will be in place over the CONUS early D4/Wednesday. Some modification of the portion of this air mass over the Plains will begin on D4/Wednesday, ahead of a low-amplitude shortwave expected to gradually move across the Southwest. This shortwave will likely interact with the returning low-level moisture late D5/Thursday and early D6/Friday, but buoyancy and shear will be modest, limiting the severe potential. This shortwave will likely continue eastward into the Lower/Mid MS Valley on D6/Friday. At the same time, upper low off the southern CA coast is expected to start progressing more eastward, potentially moving across southern CA on D6/Friday and into northern Mexico/Southwest on D7/Saturday. Modest low-level moisture is forecast to be in place over the southern Plains ahead of this wave, but warm mid-level temperatures and resultant poor lapse rates should keep the severe potential low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0321 AM CST Sun Dec 17 2023 Valid 201200Z - 251200Z ...DISCUSSION... Medium-range guidance is in good agreement that a low-amplitude upper pattern, free of any larger disturbances, and a dry continental air mass will be in place over the CONUS early D4/Wednesday. Some modification of the portion of this air mass over the Plains will begin on D4/Wednesday, ahead of a low-amplitude shortwave expected to gradually move across the Southwest. This shortwave will likely interact with the returning low-level moisture late D5/Thursday and early D6/Friday, but buoyancy and shear will be modest, limiting the severe potential. This shortwave will likely continue eastward into the Lower/Mid MS Valley on D6/Friday. At the same time, upper low off the southern CA coast is expected to start progressing more eastward, potentially moving across southern CA on D6/Friday and into northern Mexico/Southwest on D7/Saturday. Modest low-level moisture is forecast to be in place over the southern Plains ahead of this wave, but warm mid-level temperatures and resultant poor lapse rates should keep the severe potential low. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CST Sun Dec 17 2023 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Tuesday. ...Synopsis... An upper cyclone will likely be centered over PA early Tuesday morning, accompanied by cold mid-level temperatures and strong mid-level flow (i.e. 90-100 kt at 500 mb) throughout its eastern periphery. This system is forecast to gradually move eastward through the Northeast and Mid-Atlantic during the period, with largely zonal flow in its wake across the CONUS. High surface pressure associated with dry continental airmass will dominant the sensible weather east of the Rockies, limiting low-level moisture and precluding thunderstorm development. An upper low is expected to drift southward off the West Coast, ending the period centered well off the central CA Coast. A low-amplitude shortwave trough moving through the base of this upper low may move across southern CA. However, thermodynamic conditions in the vicinity of this shortwave are not conducive to lightning production. ..Mosier.. 12/17/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will become established across the western and central CONUS as a mid-level trough amplifies over the Appalachians tomorrow/Monday. Surface high pressure and cooler air will continue to overspread the Rockies to East Coast areas, as appreciable precipitation accumulates over much of California. When also considering marginal fuel statuses across the U.S., the threat for significant wildfire-spread potential currently appears negligible. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will become established across the western and central CONUS as a mid-level trough amplifies over the Appalachians tomorrow/Monday. Surface high pressure and cooler air will continue to overspread the Rockies to East Coast areas, as appreciable precipitation accumulates over much of California. When also considering marginal fuel statuses across the U.S., the threat for significant wildfire-spread potential currently appears negligible. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will become established across the western and central CONUS as a mid-level trough amplifies over the Appalachians tomorrow/Monday. Surface high pressure and cooler air will continue to overspread the Rockies to East Coast areas, as appreciable precipitation accumulates over much of California. When also considering marginal fuel statuses across the U.S., the threat for significant wildfire-spread potential currently appears negligible. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will become established across the western and central CONUS as a mid-level trough amplifies over the Appalachians tomorrow/Monday. Surface high pressure and cooler air will continue to overspread the Rockies to East Coast areas, as appreciable precipitation accumulates over much of California. When also considering marginal fuel statuses across the U.S., the threat for significant wildfire-spread potential currently appears negligible. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will become established across the western and central CONUS as a mid-level trough amplifies over the Appalachians tomorrow/Monday. Surface high pressure and cooler air will continue to overspread the Rockies to East Coast areas, as appreciable precipitation accumulates over much of California. When also considering marginal fuel statuses across the U.S., the threat for significant wildfire-spread potential currently appears negligible. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 171200Z - 181200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive upper pattern will characterize the synoptic environment over the CONUS today, with multiple mid-level troughs traversing the eastern U.S. as a third mid-level trough impinges on the California coastline. Regardless, surface high pressure and associated cooler air will surge southeast across the Rockies toward the Mississippi Valley, with wet conditions likely along the West Coast, mitigating major wildfire-spread concerns across the CONUS. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 171200Z - 181200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive upper pattern will characterize the synoptic environment over the CONUS today, with multiple mid-level troughs traversing the eastern U.S. as a third mid-level trough impinges on the California coastline. Regardless, surface high pressure and associated cooler air will surge southeast across the Rockies toward the Mississippi Valley, with wet conditions likely along the West Coast, mitigating major wildfire-spread concerns across the CONUS. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 171200Z - 181200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive upper pattern will characterize the synoptic environment over the CONUS today, with multiple mid-level troughs traversing the eastern U.S. as a third mid-level trough impinges on the California coastline. Regardless, surface high pressure and associated cooler air will surge southeast across the Rockies toward the Mississippi Valley, with wet conditions likely along the West Coast, mitigating major wildfire-spread concerns across the CONUS. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 171200Z - 181200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive upper pattern will characterize the synoptic environment over the CONUS today, with multiple mid-level troughs traversing the eastern U.S. as a third mid-level trough impinges on the California coastline. Regardless, surface high pressure and associated cooler air will surge southeast across the Rockies toward the Mississippi Valley, with wet conditions likely along the West Coast, mitigating major wildfire-spread concerns across the CONUS. ..Squitieri.. 12/17/2023 ...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 0140 AM CST Sun Dec 17 2023 Valid 171200Z - 181200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive upper pattern will characterize the synoptic environment over the CONUS today, with multiple mid-level troughs traversing the eastern U.S. as a third mid-level trough impinges on the California coastline. Regardless, surface high pressure and associated cooler air will surge southeast across the Rockies toward the Mississippi Valley, with wet conditions likely along the West Coast, mitigating major wildfire-spread concerns across the CONUS. ..Squitieri.. 12/17/2023 ...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 1258 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NJ INTO SOUTHERN NEW ENGLAND... ...SUMMARY... A few damaging gusts are possible from the eastern shore of New Jersey into southern New England Monday morning. A few isolated lightning flashes are possible along the northern/central California coast. ...NJ into Southern New England.. Upper troughing will be in place across much of the central and eastern CONUS early Monday morning. A pair of shortwave troughs will be embedded within this larger troughing, with the lead shortwave likely extending from the Upper OH Valley southeastward off the NC Coast early in the day. This shortwave is forecast to progress quickly north-northeastward, moving through the Northeast States by Monday evening. Surface low attendant to this shortwave will likely begin the period in the NJ vicinity, before then moving quickly northeastward in tandem with its parent shortwave. Anticipated path of this low may allow for a portion of the warm sector to move inland from NJ northeastward into far southern New England. Upper 50s dewpoints are anticipated within this warm sector, but warm and moist profiles will still limit buoyancy. Even so, forcing for ascent will be strong and the potential for a few deeper convective elements is possible. There is some potential for a narrow, strongly forced line of deep convection near the surface low as well. Given the robust kinematics, any deep convection could bring strong gusts to the surface, despite the shallow stable layer. However, this stable layer should keep the tornado potential very low. ...Northern/Central CA Coast... A pair of shortwave troughs are expected to move across northern CA and the Pacific Northwest on Monday. The lead shortwave is forecast to move from northern California into the northern Great Basin during the first half of the period while another shortwave moves along the Pacific Northwest coast during the second half. Strong forcing for ascent and cold mid-level temperatures could support a few isolated flashes along the northern CA coast, particularly from Monday morning into the early afternoon. ..Mosier.. 12/17/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Sun Dec 17 2023 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NJ INTO SOUTHERN NEW ENGLAND... ...SUMMARY... A few damaging gusts are possible from the eastern shore of New Jersey into southern New England Monday morning. A few isolated lightning flashes are possible along the northern/central California coast. ...NJ into Southern New England.. Upper troughing will be in place across much of the central and eastern CONUS early Monday morning. A pair of shortwave troughs will be embedded within this larger troughing, with the lead shortwave likely extending from the Upper OH Valley southeastward off the NC Coast early in the day. This shortwave is forecast to progress quickly north-northeastward, moving through the Northeast States by Monday evening. Surface low attendant to this shortwave will likely begin the period in the NJ vicinity, before then moving quickly northeastward in tandem with its parent shortwave. Anticipated path of this low may allow for a portion of the warm sector to move inland from NJ northeastward into far southern New England. Upper 50s dewpoints are anticipated within this warm sector, but warm and moist profiles will still limit buoyancy. Even so, forcing for ascent will be strong and the potential for a few deeper convective elements is possible. There is some potential for a narrow, strongly forced line of deep convection near the surface low as well. Given the robust kinematics, any deep convection could bring strong gusts to the surface, despite the shallow stable layer. However, this stable layer should keep the tornado potential very low. ...Northern/Central CA Coast... A pair of shortwave troughs are expected to move across northern CA and the Pacific Northwest on Monday. The lead shortwave is forecast to move from northern California into the northern Great Basin during the first half of the period while another shortwave moves along the Pacific Northwest coast during the second half. Strong forcing for ascent and cold mid-level temperatures could support a few isolated flashes along the northern CA coast, particularly from Monday morning into the early afternoon. ..Mosier.. 12/17/2023 Read more