Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 PM CST Mon Jan 20 2025 Valid 210100Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. tonight. ...01Z Update... Cold surface ridging has become entrenched across much of the interior U.S. through much of the Gulf Basin and offshore western Atlantic coastal waters. This will become reinforced overnight across the southern Great Plains through middle and southern Atlantic Seaboard, downstream of a pair of digging short wave troughs, where confluent mid-level flow will be maintained to the northwest of a prominent ridge centered over the subtropical western Atlantic. In advance of the southwestern of the two perturbations digging within positively tilted larger scale troughing, currently across the Southwest and adjacent international border vicinity, warm thermal and moisture advection is ongoing above the cold surface-based air across the western Gulf of Mexico into northwestern Gulf coast vicinity. This is supporting increasing precipitation offshore of the lower Texas coast, which is forecast to expand northeastward and eastward across much of the northwestern Gulf/Gulf Coast region by late tonight. Model forecast soundings continue to suggest that elevated destabilization, rooted within the 800-700 mb layer, is possible ahead of developing weak surface troughing as far northwest as the upper Texas coast by 12Z Tuesday. The NAM soundings, in particular, continue to indicate profiles which could become supportive of convection capable of producing lightning. However, based on the objective calibrated guidance of both the NCEP SREF and HREF, probabilities for this still appear less than the minimum 10 percent threshold for a categorical thunder area. ..Kerr.. 01/21/2025 Read more

No watches are valid as of Mon Jan 20 23:46:02 UTC 2025.

MD 0041 CONCERNING HEAVY SNOW FOR PORTIONS OF FAR WESTERN NEW YORK
Mesoscale Discussion 0041 NWS Storm Prediction Center Norman OK 0439 PM CST Mon Jan 20 2025 Areas affected...portions of far western New York Concerning...Heavy snow Valid 202239Z - 210245Z SUMMARY...Instances of heavy lake-effect snow should continue through the evening, with 2 inch/hour snowfall rates possible, especially over Erie County, New York. DISCUSSION...Deep-layer flow (especially closer to the surface) has become more aligned with the long axis of Lake Erie over the past couple of hours given the passing of a weak surface trough. The long fetch of appreciable low-level moisture off of the lake waters will support lake effect snow into the evening hours. 6-7 C/km low-level lapse rates (evident via 22Z mesoanalysis) will support continued heavier snowfall (as was recently observed at the DKK ASOS), with snowfall rates potentially approaching 2 inches/hour at times. ..Squitieri.. 01/20/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF... LAT...LON 42667911 42767897 42817890 42907887 42927861 42777847 42617851 42527878 42517889 42577899 42667911 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0400 PM CST Mon Jan 20 2025 Valid 221200Z - 281200Z ...Southern California - Days 3-4/Wednesday-Thursday... Within a belt of broad northwesterly flow aloft across the West, an embedded shortwave trough will track southeastward across the Great Basin into the southern Rockies/High Plains. At the same time, an upstream midlevel ridge will build over the eastern Pacific and West Coast. This will favor strengthening surface high pressure over the Intermountain West, forcing a strong offshore pressure gradient across southern CA (LAX-DAG pressure gradient around -5 to -7 mb). Given a very dry air mass in place, critical fire-weather conditions are expected over the wind-prone Santa Ana Corridor surrounding the LA Basin, as well as along the mountains/valleys in San Diego County. Current indications are that this event will peak Day 3/Wednesday night into Day 4/Thursday morning. Thereafter, onshore flow should develop across southern CA, reducing the fire-weather threat through the weekend. ...Southwest into the southern Rockies and High Plains... Dry breezy conditions are expected across the region from Day 5/Friday into the weekend ahead of a large-scale trough. However, any fire-weather concerns should remain fairly localized owing to marginal fuels -- precluding Critical probabilities at this time. ..Weinman.. 01/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Mon Jan 20 22:06:02 UTC 2025.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...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 0152 PM CST Mon Jan 20 2025 Valid 211200Z - 221200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR THE SAN GABRIEL MOUNTAINS WEST TOWARDS THE SANTA MONICA MOUNTAINS AND SANTA SUSANA MOUNTAINS...INCLUDING THE MALIBU COAST... ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN SAN DIEGO FOOTHILLS INTO THE WESTERN SAN JACINTO MOUNTAINS... ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The previous forecast (see below) remains on track, and only minor adjustments were made to the Day 2/Tuesday outlook. Most noteworthy, the Extremely Critical highlights along the San Jacinto Mountains were expanded slightly northward toward the San Bernardino Mountains in northern Riverside County. The latest high-resolution guidance is in very good agreement here, depicting a gap-flow enhancement to the winds -- favoring several hours of sustained surface winds around 40 mph (with higher gusts) amid single-digit RH. Localized extremely critical conditions are also possible along the Santa Ana Mountains during the morning/early afternoon hours. ..Weinman.. 01/20/2025 .PREV DISCUSSION... /ISSUED 0208 AM CST Mon Jan 20 2025/ ...Synopsis... A strong Santa Ana wind event beginning Monday afternoon will persist well into Tuesday afternoon and evening, resulting in widespread Critical and Extremely Critical fire-weather conditions across much of Southern California. ...Extremely Critical fire-weather conditions for the San Gabriel, Santa Monica, and Santa Susana Mountains... Extremely Critical fire-weather conditions will persist from the Day 1 outlook period (Mon) well into Day 2 (Tues). Sustained winds of 40-45 MPH (gusting 70-100 MPH on mountains, 50-80 MPH in the valleys/coastal regions) with single-digit relative humidity values as low as 2%-5% will be ongoing at the start of the period, subsiding by late Tuesday afternoon/early Tuesday evening. For more details, see the current Day 1 fire-weather outlook. ...Extremely Critical fire-weather conditions for portions of the eastern San Diego foothills into the western San Jacinto Mountains... Confidence has increased in strong, dry offshore flow across far Southern California, particularly portions of the eastern San Diego foothills into the San Jacinto Mountains. Recent 00Z HREF guidance shows ensemble mean sustained surface winds as high as 50-55 MPH, with the ensemble maximum as high as 60 MPH and gusts as high as 80 MPH. Coupled with single-digit relative humidities, this will result in several hours of Extremely Critical fire-weather conditions supportive of rapid wildfire onset and spread, subsiding by late Tuesday evening into Wednesday morning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0141 PM CST Mon Jan 20 2025 Valid 202000Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... No thunderstorms are expected across the U.S. through tonight. ...20z Update... No changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton/Mosier.. 01/20/2025 .PREV DISCUSSION... /ISSUED 1028 AM CST Mon Jan 20 2025/ ...Synopsis... Another surge of cold air is anticipated across the CONUS, reinforcing the polar airmass already in place. This will result in a maintenance of dry and stable conditions, with no thunderstorms anticipated. Some deeper convection is possible late tonight/early tomorrow along the middle/upper TX Coast as warm-air advection strengthens throughout the warm sector of surface low developing over the western Gulf of Mexico. Model forecast soundings have thermodynamic profiles with scant (and shallow) buoyancy between around 800 to 500 mb. These profiles also suggest sleet will be the predominant precipitation type, with mixed-phase parcels combining with the modest buoyancy to support a few lightning flashes. Even so, the overall thunderstorm probabilities are still expected to be less than 10 percent. Read more