Storm Prediction Center

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0135 PM CST Sat Dec 20 2025 Valid 202000Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few lightning flashes may occur today across parts of coastal Washington/Oregon and tonight over southern Louisiana. Severe thunderstorms are not expected. ...20Z Update... No changes have been made to the ongoing forecast. See the previous discussion below for more information. ..Gleason.. 12/20/2025 .PREV DISCUSSION... /ISSUED 0953 AM CST Sat Dec 20 2025/ Dry and stable conditions will prevail over most of the CONUS today, precluding thunderstorms. One exception will be over western WA west of the Cascades, where fast onshore flow, orographic lift, and 100-200 J/kg of CAPE will be present. The other area of some risk of lightning will be over southern LA tonight in a weak low-level warm advection regime. In both areas, thunderstorm coverage is anticipated to be sparse and severe risk negligible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0135 PM CST Sat Dec 20 2025 Valid 202000Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few lightning flashes may occur today across parts of coastal Washington/Oregon and tonight over southern Louisiana. Severe thunderstorms are not expected. ...20Z Update... No changes have been made to the ongoing forecast. See the previous discussion below for more information. ..Gleason.. 12/20/2025 .PREV DISCUSSION... /ISSUED 0953 AM CST Sat Dec 20 2025/ Dry and stable conditions will prevail over most of the CONUS today, precluding thunderstorms. One exception will be over western WA west of the Cascades, where fast onshore flow, orographic lift, and 100-200 J/kg of CAPE will be present. The other area of some risk of lightning will be over southern LA tonight in a weak low-level warm advection regime. In both areas, thunderstorm coverage is anticipated to be sparse and severe risk negligible. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Sat Dec 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Update... No changes are needed for the Day 2 forecast. Please see the discussion below for additional information. ..Barnes.. 12/20/2025 .PREV DISCUSSION... /ISSUED 0112 AM CST Sat Dec 20 2025/ ...Synopsis... Upper ridging will prevail over much of the CONUS tomorrow (Sunday), with surface high pressure becoming established east of the Mississippi River as surface lee troughing and associated southerly flow overspreads the Plains states. While breezy conditions are likely across parts of the central into southern Plains, modest moisture return may accompany the windy southerly flow, which may limit wildfire-spread potential. As such, overall quiescent fire weather conditions are likely across the CONUS on Sunday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 PM CST Sat Dec 20 2025 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... Upper-level ridging will continue across much of the CONUS on Monday. A compact, moderately strong shortwave trough will move into the Pacific Northwest by mid/late afternoon. As the surface high continues to move south and east through the Mid-Atlantic, moisture return will occur in the western/central Gulf Coast regions. Very isolated thunderstorm activity could occur near the Texas Gulf Coast, but this potential should be quite limited given ridging aloft and weak low-level forcing. Within the coastal Northwest, cold temperatures aloft are expected to support isolated, low-topped thunderstorm activity late afternoon into early evening. ..Wendt.. 12/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CST Sat Dec 20 2025 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected Sunday. ...Synopsis... Zonal flow aloft will become modestly more amplified on Sunday. Upper-level ridging will become more prominent in the central U.S. A low-amplitude shortwave trough will move into the Northwest during the evening. Isolated low-topped thunderstorms may impact coastal areas of Washington and far northwest Oregon. Along the central Gulf coast, a cold front will slow and become nearly stationary inland. A weak warm/moist advection regime could lead to development of showers. Given the slight rise in mid-level heights, residual capping, and lack of greater low-level forcing, potential for thunderstorm development within this regime still appears low. ..Wendt.. 12/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CST Sat Dec 20 2025 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected Sunday. ...Synopsis... Zonal flow aloft will become modestly more amplified on Sunday. Upper-level ridging will become more prominent in the central U.S. A low-amplitude shortwave trough will move into the Northwest during the evening. Isolated low-topped thunderstorms may impact coastal areas of Washington and far northwest Oregon. Along the central Gulf coast, a cold front will slow and become nearly stationary inland. A weak warm/moist advection regime could lead to development of showers. Given the slight rise in mid-level heights, residual capping, and lack of greater low-level forcing, potential for thunderstorm development within this regime still appears low. ..Wendt.. 12/20/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1035 AM CST Sat Dec 20 2025 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN NEW MEXICO INTO THE TEXAS SOUTH PLAINS... ...Update... No changes were required for today's forecast. Expect increasing westerly winds throughout the afternoon, with RH dropping into the low teens to single digits. Please see the previous discussion for additional details. ..Barnes.. 12/20/2025 .PREV DISCUSSION... /ISSUED 0110 AM CST Sat Dec 20 2025/ ...Synopsis... A mid-level trough will gradually amplify while traversing the Great Lakes today, encouraging the southward translation of a weakening surface low across the southern Plains. As a result, dry downslope flow is expected across portions of eastern New Mexico into western Texas ahead of a southward-sagging surface cold front today. During the afternoon, with boundary-layer mixing, RH will drop below 20 percent over several locales as sustained westerly surface winds exceeding 15 mph becomes abundant, warranting the continuation of Elevated highlights. Guidance consensus continues to depict overlapping 20+ mph sustained westerly surface winds amid 15 percent RH along portions of the New Mexico/Texas border, where Critical highlights have been maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Sat Dec 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few lightning flashes may occur today near coastal Washington, and tonight over southern Louisiana. Dry and stable conditions will prevail over most of the CONUS today, precluding thunderstorms. One exception will be over western WA west of the Cascades, where fast onshore flow, orographic lift, and 100-200 J/kg of CAPE will be present. The other area of some risk of lightning will be over southern LA tonight in a weak low-level warm advection regime. In both areas, thunderstorm coverage is anticipated to be sparse and severe risk negligible. ..Hart/Karstens.. 12/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0632 AM CST Sat Dec 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected, but a few lightning flashes may occur today near coastal Washington. ...Discussion... Progressive/low-amplitude flow aloft will prevail over the CONUS to the south of an amplifying shortwave trough over the Great Lakes/Ontario. Surface high pressure will expand eastward across the Plains and Midwest. Some inland moistening will occur across east Texas toward the Lower Mississippi Valley via the western Gulf, but weak forcing/capping will hinder appreciable convective development. In the Pacific Northwest, a marginally supportive thermodynamic environment may allow for a few lightning flashes near the Washington coast today and tonight. ..Guyer/Marsh.. 12/20/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0236 AM CST Sat Dec 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... The large-scale pattern next week will be highlighted by prominent upper ridging and anomalously high 500-mb heights over much of the central to eastern CONUS, with upper troughing developing toward the West Coast by mid/late week. This pattern should considerably limit deep convective potential over much of the CONUS, even while a relatively warm/moist airmass will exist across the Plains and Midwest. With the approach of a low-latitude upper trough and increasing moisture, thunderstorm potential, potentially including some strong/locally severe storms with gusty winds, could occur across coastal portions of central and southern California during the last half of Wednesday/Day 5 into Thursday/Day 6 Christmas. However, the degree of destabilization and some synoptic-related forecast details remain uncertain. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0236 AM CST Sat Dec 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... The large-scale pattern next week will be highlighted by prominent upper ridging and anomalously high 500-mb heights over much of the central to eastern CONUS, with upper troughing developing toward the West Coast by mid/late week. This pattern should considerably limit deep convective potential over much of the CONUS, even while a relatively warm/moist airmass will exist across the Plains and Midwest. With the approach of a low-latitude upper trough and increasing moisture, thunderstorm potential, potentially including some strong/locally severe storms with gusty winds, could occur across coastal portions of central and southern California during the last half of Wednesday/Day 5 into Thursday/Day 6 Christmas. However, the degree of destabilization and some synoptic-related forecast details remain uncertain. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0126 AM CST Sat Dec 20 2025 Valid 221200Z - 231200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Discussion... The large-scale pattern will undergo modest amplification on Monday via additional upper ridging over the south-central CONUS and northern Mexico. As a surface high continues to transition east-southeastward along the Eastern Seaboard/Southeast, moderate low-level moistening will occur north-northeastward across Louisiana/eastern half of Texas toward the ArkLaTex. A few thunderstorms could occur within this warm/moist advection regime, but it currently appears that upper ridging and related mid-level capping should considerably limit thunderstorm potential. In the Pacific Northwest, a few lightning flashes could occur near coastal Washington, but this potential should remain limited/isolated while also trending less thermodynamically favorable by late in the day. ..Guyer.. 12/20/2025 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0126 AM CST Sat Dec 20 2025 Valid 221200Z - 231200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Discussion... The large-scale pattern will undergo modest amplification on Monday via additional upper ridging over the south-central CONUS and northern Mexico. As a surface high continues to transition east-southeastward along the Eastern Seaboard/Southeast, moderate low-level moistening will occur north-northeastward across Louisiana/eastern half of Texas toward the ArkLaTex. A few thunderstorms could occur within this warm/moist advection regime, but it currently appears that upper ridging and related mid-level capping should considerably limit thunderstorm potential. In the Pacific Northwest, a few lightning flashes could occur near coastal Washington, but this potential should remain limited/isolated while also trending less thermodynamically favorable by late in the day. ..Guyer.. 12/20/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 AM CST Sat Dec 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will prevail over much of the CONUS tomorrow (Sunday), with surface high pressure becoming established east of the Mississippi River as surface lee troughing and associated southerly flow overspreads the Plains states. While breezy conditions are likely across parts of the central into southern Plains, modest moisture return may accompany the windy southerly flow, which may limit wildfire-spread potential. As such, overall quiescent fire weather conditions are likely across the CONUS on Sunday. ..Squitieri.. 12/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 AM CST Sat Dec 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Upper ridging will prevail over much of the CONUS tomorrow (Sunday), with surface high pressure becoming established east of the Mississippi River as surface lee troughing and associated southerly flow overspreads the Plains states. While breezy conditions are likely across parts of the central into southern Plains, modest moisture return may accompany the windy southerly flow, which may limit wildfire-spread potential. As such, overall quiescent fire weather conditions are likely across the CONUS on Sunday. ..Squitieri.. 12/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0110 AM CST Sat Dec 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF FAR EASTERN NEW MEXICO INTO THE TEXAS SOUTH PLAINS... ...Synopsis... A mid-level trough will gradually amplify while traversing the Great Lakes today, encouraging the southward translation of a weakening surface low across the southern Plains. As a result, dry downslope flow is expected across portions of eastern New Mexico into western Texas ahead of a southward-sagging surface cold front today. During the afternoon, with boundary-layer mixing, RH will drop below 20 percent over several locales as sustained westerly surface winds exceeding 15 mph becomes abundant, warranting the continuation of Elevated highlights. Guidance consensus continues to depict overlapping 20+ mph sustained westerly surface winds amid 15 percent RH along portions of the New Mexico/Texas border, where Critical highlights have been maintained. ..Squitieri.. 12/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0110 AM CST Sat Dec 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF FAR EASTERN NEW MEXICO INTO THE TEXAS SOUTH PLAINS... ...Synopsis... A mid-level trough will gradually amplify while traversing the Great Lakes today, encouraging the southward translation of a weakening surface low across the southern Plains. As a result, dry downslope flow is expected across portions of eastern New Mexico into western Texas ahead of a southward-sagging surface cold front today. During the afternoon, with boundary-layer mixing, RH will drop below 20 percent over several locales as sustained westerly surface winds exceeding 15 mph becomes abundant, warranting the continuation of Elevated highlights. Guidance consensus continues to depict overlapping 20+ mph sustained westerly surface winds amid 15 percent RH along portions of the New Mexico/Texas border, where Critical highlights have been maintained. ..Squitieri.. 12/20/2025 ...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 1148 PM CST Fri Dec 19 2025 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected Sunday. ...Discussion... Progressive/generally zonal upper-level flow will prevail over the CONUS on Sunday. A low-amplitude shortwave trough will move inland over the Pacific Northwest, with thermodynamic profiles potentially becoming conducive for a few low-topped thunderstorms mainly for coastal portions of Washington. East of the Rockies, surface high pressure and continental trajectories will be prevalent with essentially nil thunderstorm potential. Gradual air mass modification and low-level moistening will occur over the western Gulf. However, a limited forcing regime and residual capping are currently expected to preclude thunderstorms along the Texas coast. ..Guyer.. 12/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 PM CST Fri Dec 19 2025 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes may occur near coastal sections of Washington today. ...Synopsis... A mid-level trough will progress across the eastern CONUS while upper ridging builds west of the Rockies, resulting in surface high pressure overspreading the Midwest as a surface trough impinges on the Pacific Northwest Coastline. Cooler temperatures aloft will overspread a marine boundary layer over the Washington coast, resulting in scant buoyancy, which may favor a few convective updrafts that may deepen enough to produce isolated lightning flashes. A weakening surface low will also drift southward across the southern Plains, promoting low-level moisture return inland from the western Gulf. However, considerable convective inhibition should limit convective development through the Day 1 period. ..Squitieri.. 12/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 PM CST Fri Dec 19 2025 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes may occur near coastal sections of Washington today. ...Synopsis... A mid-level trough will progress across the eastern CONUS while upper ridging builds west of the Rockies, resulting in surface high pressure overspreading the Midwest as a surface trough impinges on the Pacific Northwest Coastline. Cooler temperatures aloft will overspread a marine boundary layer over the Washington coast, resulting in scant buoyancy, which may favor a few convective updrafts that may deepen enough to produce isolated lightning flashes. A weakening surface low will also drift southward across the southern Plains, promoting low-level moisture return inland from the western Gulf. However, considerable convective inhibition should limit convective development through the Day 1 period. ..Squitieri.. 12/20/2025 Read more