Severe Storms

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

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

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 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1137 PM CST Sat Dec 16 2023 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CAROLINAS... ...SUMMARY... Severe thunderstorms are possible today across coastal Carolinas. Damaging winds and some tornado threat are the primary hazards. ...Coastal Carolinas... Late-evening satellite imagery depicts a well-defined midlevel short-wave trough ejecting northeast toward the northern Florida Peninsula. This feature is forecast to advance across the Carolinas later today. In response, a very strong LLJ has developed which will nose into southern SC by 17/12z. 850mb flow is forecast to increase in excess of 80kt by 18/00z across eastern NC into extreme southeast VA. Latest model guidance suggests the associated surface low will track from off the northeast FL Coast to near CRE by early evening, then lift north along the middle Atlantic Coast into NJ during the overnight hours. This evolution suggests modified boundary-layer air mass will advance inland across coastal Carolinas permitting adequate surface-based buoyancy to develop immediately ahead of the surface low. Forecast soundings exhibit modest instability near the coast with MLCAPE approaching 1000 J/kg where dew points can rise into the upper 60s. While lapse rates will remain poor, very strong deep-layer shear/SRH favor supercells. Damaging winds are certainly possible with more organized convection given that 50-70kt winds should be within 1km AGL. Isolated tornado threat can also be expected with any supercells that emerge within this environment. ..Darrow/Squitieri.. 12/17/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1137 PM CST Sat Dec 16 2023 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CAROLINAS... ...SUMMARY... Severe thunderstorms are possible today across coastal Carolinas. Damaging winds and some tornado threat are the primary hazards. ...Coastal Carolinas... Late-evening satellite imagery depicts a well-defined midlevel short-wave trough ejecting northeast toward the northern Florida Peninsula. This feature is forecast to advance across the Carolinas later today. In response, a very strong LLJ has developed which will nose into southern SC by 17/12z. 850mb flow is forecast to increase in excess of 80kt by 18/00z across eastern NC into extreme southeast VA. Latest model guidance suggests the associated surface low will track from off the northeast FL Coast to near CRE by early evening, then lift north along the middle Atlantic Coast into NJ during the overnight hours. This evolution suggests modified boundary-layer air mass will advance inland across coastal Carolinas permitting adequate surface-based buoyancy to develop immediately ahead of the surface low. Forecast soundings exhibit modest instability near the coast with MLCAPE approaching 1000 J/kg where dew points can rise into the upper 60s. While lapse rates will remain poor, very strong deep-layer shear/SRH favor supercells. Damaging winds are certainly possible with more organized convection given that 50-70kt winds should be within 1km AGL. Isolated tornado threat can also be expected with any supercells that emerge within this environment. ..Darrow/Squitieri.. 12/17/2023 Read more