Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1015 AM CST Tue Jan 07 2025 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... The previous forecast remains on track with some modifications made to reflect recent observed trends and 12z guidance. Regional radars show light to moderate precipitation falling across southern CA - mainly on the windward side of the coastal terrain. MRMS QPE suggests most locations on the lee side of the coastal ranges have not received wetting rainfall, so impacts to fuels should remain limited. 16 UTC surface observations show downslope winds beginning to increase with gusts between 40-60 mph becoming more common at higher elevation. As of 16 UTC, cloud cover is modulating the influence of downslope warming/drying with RH values generally above 30%; however, relative humidity is expected to quickly decline by mid/late afternoon as cloud cover/precipitation shifts southeast in tandem with the upper trough over the region. Consequently, confidence remains high that the fire weather threat will increase this afternoon through the early morning hours Wednesday. High-resolution guidance suggests peak winds are probable during the 09-15 UTC period Wednesday with gusts between 60-80 mph likely at higher elevation (with locally stronger gusts possible). Critical RH thresholds will likely be maintained through the overnight period across western Los Angeles to Ventura and eastern Santa Barbara counties, but may recover into the upper teens southward along the coast. ..Moore.. 01/07/2025 .PREV DISCUSSION... /ISSUED 0137 AM CST Tue Jan 07 2025/ ...Synopsis... A broad trough across the West will undergo intensification today. A strong mid-level jet will develop in the western Great Basin and California. At the surface, high pressure will strengthen in the Great Basin into the lower Colorado River Valley. ...Southern California... The offshore pressure gradient may be sufficient to support elevated to critical fire weather by this afternoon. RH will be the main uncertainty during the afternoon, but around 20% appears likely and near 15% is certainly possible. Winds this afternoon will peak at 20-25 mph outside of the terrain. Both the offshore gradient and the supporting upper-level winds are expected to increase in magnitude during the evening/overnight into Wednesday morning. The strongest upper-level winds (and thus wind gusts) are most likely around very late today to early Wednesday. How low RH will remain overnight is also somewhat uncertain, but wind strength (25-35 mph) would still support higher-end critical conditions in the typical Santa Ana corridors in LA/Ventura Counties. ...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 1015 AM CST Tue Jan 07 2025 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... The previous forecast remains on track with some modifications made to reflect recent observed trends and 12z guidance. Regional radars show light to moderate precipitation falling across southern CA - mainly on the windward side of the coastal terrain. MRMS QPE suggests most locations on the lee side of the coastal ranges have not received wetting rainfall, so impacts to fuels should remain limited. 16 UTC surface observations show downslope winds beginning to increase with gusts between 40-60 mph becoming more common at higher elevation. As of 16 UTC, cloud cover is modulating the influence of downslope warming/drying with RH values generally above 30%; however, relative humidity is expected to quickly decline by mid/late afternoon as cloud cover/precipitation shifts southeast in tandem with the upper trough over the region. Consequently, confidence remains high that the fire weather threat will increase this afternoon through the early morning hours Wednesday. High-resolution guidance suggests peak winds are probable during the 09-15 UTC period Wednesday with gusts between 60-80 mph likely at higher elevation (with locally stronger gusts possible). Critical RH thresholds will likely be maintained through the overnight period across western Los Angeles to Ventura and eastern Santa Barbara counties, but may recover into the upper teens southward along the coast. ..Moore.. 01/07/2025 .PREV DISCUSSION... /ISSUED 0137 AM CST Tue Jan 07 2025/ ...Synopsis... A broad trough across the West will undergo intensification today. A strong mid-level jet will develop in the western Great Basin and California. At the surface, high pressure will strengthen in the Great Basin into the lower Colorado River Valley. ...Southern California... The offshore pressure gradient may be sufficient to support elevated to critical fire weather by this afternoon. RH will be the main uncertainty during the afternoon, but around 20% appears likely and near 15% is certainly possible. Winds this afternoon will peak at 20-25 mph outside of the terrain. Both the offshore gradient and the supporting upper-level winds are expected to increase in magnitude during the evening/overnight into Wednesday morning. The strongest upper-level winds (and thus wind gusts) are most likely around very late today to early Wednesday. How low RH will remain overnight is also somewhat uncertain, but wind strength (25-35 mph) would still support higher-end critical conditions in the typical Santa Ana corridors in LA/Ventura Counties. ...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 1015 AM CST Tue Jan 07 2025 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... The previous forecast remains on track with some modifications made to reflect recent observed trends and 12z guidance. Regional radars show light to moderate precipitation falling across southern CA - mainly on the windward side of the coastal terrain. MRMS QPE suggests most locations on the lee side of the coastal ranges have not received wetting rainfall, so impacts to fuels should remain limited. 16 UTC surface observations show downslope winds beginning to increase with gusts between 40-60 mph becoming more common at higher elevation. As of 16 UTC, cloud cover is modulating the influence of downslope warming/drying with RH values generally above 30%; however, relative humidity is expected to quickly decline by mid/late afternoon as cloud cover/precipitation shifts southeast in tandem with the upper trough over the region. Consequently, confidence remains high that the fire weather threat will increase this afternoon through the early morning hours Wednesday. High-resolution guidance suggests peak winds are probable during the 09-15 UTC period Wednesday with gusts between 60-80 mph likely at higher elevation (with locally stronger gusts possible). Critical RH thresholds will likely be maintained through the overnight period across western Los Angeles to Ventura and eastern Santa Barbara counties, but may recover into the upper teens southward along the coast. ..Moore.. 01/07/2025 .PREV DISCUSSION... /ISSUED 0137 AM CST Tue Jan 07 2025/ ...Synopsis... A broad trough across the West will undergo intensification today. A strong mid-level jet will develop in the western Great Basin and California. At the surface, high pressure will strengthen in the Great Basin into the lower Colorado River Valley. ...Southern California... The offshore pressure gradient may be sufficient to support elevated to critical fire weather by this afternoon. RH will be the main uncertainty during the afternoon, but around 20% appears likely and near 15% is certainly possible. Winds this afternoon will peak at 20-25 mph outside of the terrain. Both the offshore gradient and the supporting upper-level winds are expected to increase in magnitude during the evening/overnight into Wednesday morning. The strongest upper-level winds (and thus wind gusts) are most likely around very late today to early Wednesday. How low RH will remain overnight is also somewhat uncertain, but wind strength (25-35 mph) would still support higher-end critical conditions in the typical Santa Ana corridors in LA/Ventura Counties. ...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 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Jan 07 2025 Valid 071630Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... Within the base of a highly amplified large-scale trough over the West, a midlevel vorticity maximum will phase with steep midlevel lapse rates over southwestern AZ today. While weak buoyancy will develop atop a dry low-level air mass (inverted-V-type sounding), convection should remain too weak for lightning owing to the limited moisture. Elsewhere, a cold/dry air mass will preclude thunderstorm potential across the CONUS. ..Weinman.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0639 AM CST Tue Jan 07 2025 Valid 071300Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Discussion... The widespread prevalence of surface high pressure and cold continental trajectories is expected to preclude thunderstorm development across the CONUS. Minimal mid-level buoyancy could develop across parts of Arizona this afternoon and evening as lapse rates steepen east of the amplifying trough over the Southwest/Baja vicinity. However, convection should remain very weak in a moisture-starved environment, and no thunderstorms are expected. ..Guyer/Bentley.. 01/07/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CST Tue Jan 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... A mid-level trough is forecast to move across the southern Plains on Friday/Day 4, as flow ahead of the system remains southwesterly over much of the Southeast. At the surface, a front is forecast to move into the central Gulf Coast region, with a moist airmass located ahead of the front mostly offshore. Thunderstorm activity will be possible from Friday into Saturday along and ahead of the front at the northern edge of this moist airmass in the coastal sections from Louisiana to Florida. From Sunday/Day 6 to Tuesday/Day 8, large-scale mid-level troughing is forecast to persist over the central U.S. In response, high pressure is forecast to remain dominant over much of the continental U.S. late in the Day 4 to 8 period. Due to this cold and dry airmass, thunderstorms will be unlikely. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CST Tue Jan 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... A mid-level trough is forecast to move across the southern Plains on Friday/Day 4, as flow ahead of the system remains southwesterly over much of the Southeast. At the surface, a front is forecast to move into the central Gulf Coast region, with a moist airmass located ahead of the front mostly offshore. Thunderstorm activity will be possible from Friday into Saturday along and ahead of the front at the northern edge of this moist airmass in the coastal sections from Louisiana to Florida. From Sunday/Day 6 to Tuesday/Day 8, large-scale mid-level troughing is forecast to persist over the central U.S. In response, high pressure is forecast to remain dominant over much of the continental U.S. late in the Day 4 to 8 period. Due to this cold and dry airmass, thunderstorms will be unlikely. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CST Tue Jan 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... A mid-level trough is forecast to move across the southern Plains on Friday/Day 4, as flow ahead of the system remains southwesterly over much of the Southeast. At the surface, a front is forecast to move into the central Gulf Coast region, with a moist airmass located ahead of the front mostly offshore. Thunderstorm activity will be possible from Friday into Saturday along and ahead of the front at the northern edge of this moist airmass in the coastal sections from Louisiana to Florida. From Sunday/Day 6 to Tuesday/Day 8, large-scale mid-level troughing is forecast to persist over the central U.S. In response, high pressure is forecast to remain dominant over much of the continental U.S. late in the Day 4 to 8 period. Due to this cold and dry airmass, thunderstorms will be unlikely. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CST Tue Jan 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... A mid-level trough is forecast to move across the southern Plains on Friday/Day 4, as flow ahead of the system remains southwesterly over much of the Southeast. At the surface, a front is forecast to move into the central Gulf Coast region, with a moist airmass located ahead of the front mostly offshore. Thunderstorm activity will be possible from Friday into Saturday along and ahead of the front at the northern edge of this moist airmass in the coastal sections from Louisiana to Florida. From Sunday/Day 6 to Tuesday/Day 8, large-scale mid-level troughing is forecast to persist over the central U.S. In response, high pressure is forecast to remain dominant over much of the continental U.S. late in the Day 4 to 8 period. Due to this cold and dry airmass, thunderstorms will be unlikely. Read more