Yosemite National Park Warnings, Watches and Advisories

Do not drive vehicles through flooded areas. The water depth or fast flowing water/mud/debris from a flash flood will make road conditions unsafe. Do not rely soley on data presented here or other third-party websites - always check your official national and local weather service agency website, socials, radio and/or TV stations for making critical decisions related to weather events.

Please carefully read each posted Warning and Alert as it relates to the area(s) being affected. We may provide a wider range of issued severe weather warnings for surrounding cities and counties, so some alerts may not directly impact this location. This is done to help with preparing for severe weather that may overlap or be heading towards Yosemite National Park.

Use the Radar Maps link provided to understand the trajectory of a storm.

Red Flag Warning issued December 8 at 4:04PM PST until December 10 at 10:00PM PST by NWS Los Angeles/Oxnard CA

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SANTA MONICA MOUNTAINS/ SANTA CLARITA VALLEY/ VENTURA COUNTY COASTS AND VALLEYS/ WESTERN SAN FERNANDO VALLEY -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THESE SAME AREAS... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 AM WEDNESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SANTA SUSANA MOUNTAINS-- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THIS SAME AREA... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: VENTURA COASTAL PLAIN (ESPECIALLY FOOTHILLS)/ MALIBU COAST -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 2 PM MONDAY UNTIL 2 PM WEDNESDAY IN THESE SAME AREAS... ...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY FOR VENTURA MOUNTAINS, I5 CORRIDOR, EASTERN SAN FERNANDO VALLEY, AND SAN GABRIEL VALLEY DUE TO GUSTY SANTA ANA WINDS AND VERY LOW HUMIDITIES... ...RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 PM TUESDAY FOR THE SAN LUIS OBISPO COUNTY MOUNTAINS DUE TO GUSTY EAST TO SOUTHEAST WINDS AND VERY LOW HUMIDITIES... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR MANY AREAS OF LOS ANGELES AND VENTURA COUNTIES *** A strong, widespread, and long duration Santa Ana event will bring widespread critical to extremely critical fire weather conditions to many areas of Los Angeles and Ventura counties Monday into Wednesday. This will be a PARTICULAR DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of a strong offshore pressure gradient (LAX-Daggett peaking at -8 to -9 mb), strong cold air advection, and moderate upper level wind support. As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, there is high confidence for a long duration Red Flag event. In addition, there is high confidence of of PDS Red Flag Warning conditions late Monday evening through Tuesday, as damaging wind gusts of 60 to 80 mph will likely overlap with single digit humidities across many of the windier mountain and foothills areas, and with gusts of 40 to 65 mph across most wind prone coastal and valley areas of Los Angeles and Ventura counties. With the threat of damaging wind gusts in these windier corridors, there will be an increased risk for downed trees and powerlines, along with power outages. The hardest hit areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando), and the hills above Camarillo into east Ventura. Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior (including long range spotting). As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires. Dry offshore conditions will likely persist into Thursday. * WINDS...Southeast to east 15 to 30 mph with gusts to 40 mph. * RELATIVE HUMIDITY...Widespread single digit humidities developing by later Monday night or Tuesday. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property.

Red Flag Warning issued December 8 at 4:04PM PST until December 11 at 2:00PM PST by NWS Los Angeles/Oxnard CA

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SANTA MONICA MOUNTAINS/ SANTA CLARITA VALLEY/ VENTURA COUNTY COASTS AND VALLEYS/ WESTERN SAN FERNANDO VALLEY -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THESE SAME AREAS... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 AM WEDNESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SANTA SUSANA MOUNTAINS-- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THIS SAME AREA... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: VENTURA COASTAL PLAIN (ESPECIALLY FOOTHILLS)/ MALIBU COAST -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 2 PM MONDAY UNTIL 2 PM WEDNESDAY IN THESE SAME AREAS... ...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY FOR VENTURA MOUNTAINS, I5 CORRIDOR, EASTERN SAN FERNANDO VALLEY, AND SAN GABRIEL VALLEY DUE TO GUSTY SANTA ANA WINDS AND VERY LOW HUMIDITIES... ...RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 PM TUESDAY FOR THE SAN LUIS OBISPO COUNTY MOUNTAINS DUE TO GUSTY EAST TO SOUTHEAST WINDS AND VERY LOW HUMIDITIES... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR MANY AREAS OF LOS ANGELES AND VENTURA COUNTIES *** A strong, widespread, and long duration Santa Ana event will bring widespread critical to extremely critical fire weather conditions to many areas of Los Angeles and Ventura counties Monday into Wednesday. This will be a PARTICULAR DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of a strong offshore pressure gradient (LAX-Daggett peaking at -8 to -9 mb), strong cold air advection, and moderate upper level wind support. As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, there is high confidence for a long duration Red Flag event. In addition, there is high confidence of of PDS Red Flag Warning conditions late Monday evening through Tuesday, as damaging wind gusts of 60 to 80 mph will likely overlap with single digit humidities across many of the windier mountain and foothills areas, and with gusts of 40 to 65 mph across most wind prone coastal and valley areas of Los Angeles and Ventura counties. With the threat of damaging wind gusts in these windier corridors, there will be an increased risk for downed trees and powerlines, along with power outages. The hardest hit areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando), and the hills above Camarillo into east Ventura. Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior (including long range spotting). As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires. Dry offshore conditions will likely persist into Thursday. * A particularly dangerous situation exists for these areas due to the combination of damaging winds, single digit humidities, and extremely dry vegetation. Any new fire ignitions in this area will have dangerous fire spread with a significant threat to life and property. * WINDS...Santa Ana winds expected to increase sharply by mid to late Monday afternoon, then peak later Monday evening through Tuesday, when speeds of 25 to 40 mph with gusts of 40 to 55 mph will likely be common. Isolated damaging gusts of 55 to 65 mph will be possible in the hills above Camarillo and Somis extending into east Ventura, as well as Point Mugu and Malibu. * RELATIVE HUMIDITY...Humidities are expected to lower to around 15 percent in many areas by late Monday afternoon or evening, with widespread humidities of 5 to 10 percent likely from late Monday evening into Tuesday, and persisting into Wednesday, with isolated readings as low as 2 percent likely. * IMPACTS...If fire ignition occurs, conditions are favorable for large fires with very rapid fire spread, extreme fire behavior, and long range spotting, which would threaten life and property. There is also the risk of damaging winds including trees and power lines, as well as power outages.

Red Flag Warning issued December 8 at 4:04PM PST until December 11 at 6:00PM PST by NWS Los Angeles/Oxnard CA

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SANTA MONICA MOUNTAINS/ SANTA CLARITA VALLEY/ VENTURA COUNTY COASTS AND VALLEYS/ WESTERN SAN FERNANDO VALLEY -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THESE SAME AREAS... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 AM WEDNESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SANTA SUSANA MOUNTAINS-- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THIS SAME AREA... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: VENTURA COASTAL PLAIN (ESPECIALLY FOOTHILLS)/ MALIBU COAST -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 2 PM MONDAY UNTIL 2 PM WEDNESDAY IN THESE SAME AREAS... ...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY FOR VENTURA MOUNTAINS, I5 CORRIDOR, EASTERN SAN FERNANDO VALLEY, AND SAN GABRIEL VALLEY DUE TO GUSTY SANTA ANA WINDS AND VERY LOW HUMIDITIES... ...RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 PM TUESDAY FOR THE SAN LUIS OBISPO COUNTY MOUNTAINS DUE TO GUSTY EAST TO SOUTHEAST WINDS AND VERY LOW HUMIDITIES... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR MANY AREAS OF LOS ANGELES AND VENTURA COUNTIES *** A strong, widespread, and long duration Santa Ana event will bring widespread critical to extremely critical fire weather conditions to many areas of Los Angeles and Ventura counties Monday into Wednesday. This will be a PARTICULAR DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of a strong offshore pressure gradient (LAX-Daggett peaking at -8 to -9 mb), strong cold air advection, and moderate upper level wind support. As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, there is high confidence for a long duration Red Flag event. In addition, there is high confidence of of PDS Red Flag Warning conditions late Monday evening through Tuesday, as damaging wind gusts of 60 to 80 mph will likely overlap with single digit humidities across many of the windier mountain and foothills areas, and with gusts of 40 to 65 mph across most wind prone coastal and valley areas of Los Angeles and Ventura counties. With the threat of damaging wind gusts in these windier corridors, there will be an increased risk for downed trees and powerlines, along with power outages. The hardest hit areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando), and the hills above Camarillo into east Ventura. Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior (including long range spotting). As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires. Dry offshore conditions will likely persist into Thursday. * A particularly dangerous situation exists for this area due to the combination of damaging winds, single digit humidities, and extremely dry vegetation. Any new fire ignitions in this area will have dangerous fire spread with a significant threat to life and property. * WINDS...Santa Ana winds expected to increase sharply late Monday morning into afternoon, then peak Monday night into early Wednesday morning. when speeds of 30 to 50 mph with gusts of 65 to 80 mph are likely. Offshore winds are expected to diminish some by late Wednesday morning, with gusts mostly in the 20 to 40 mph range. * RELATIVE HUMIDITY...Humidities are expected to lower to around 15 percent by Monday afternoon or early evening, with widespread humidities of 5 to 10 percent likely later Monday evening into Tuesday, and persisting into Wednesday, with isolated readings as low as 2 percent likely. * IMPACTS...If fire ignition occurs, conditions are favorable for large fires with very rapid fire spread, extreme fire behavior, and long range spotting, which would threaten life and property. There is also the risk of damaging winds including trees and power lines, as well as power outages.

Red Flag Warning issued December 8 at 4:04PM PST until December 11 at 6:00PM PST by NWS Los Angeles/Oxnard CA

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SANTA MONICA MOUNTAINS/ SANTA CLARITA VALLEY/ VENTURA COUNTY COASTS AND VALLEYS/ WESTERN SAN FERNANDO VALLEY -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THESE SAME AREAS... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 AM WEDNESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SANTA SUSANA MOUNTAINS-- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THIS SAME AREA... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: VENTURA COASTAL PLAIN (ESPECIALLY FOOTHILLS)/ MALIBU COAST -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 2 PM MONDAY UNTIL 2 PM WEDNESDAY IN THESE SAME AREAS... ...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY FOR VENTURA MOUNTAINS, I5 CORRIDOR, EASTERN SAN FERNANDO VALLEY, AND SAN GABRIEL VALLEY DUE TO GUSTY SANTA ANA WINDS AND VERY LOW HUMIDITIES... ...RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 PM TUESDAY FOR THE SAN LUIS OBISPO COUNTY MOUNTAINS DUE TO GUSTY EAST TO SOUTHEAST WINDS AND VERY LOW HUMIDITIES... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR MANY AREAS OF LOS ANGELES AND VENTURA COUNTIES *** A strong, widespread, and long duration Santa Ana event will bring widespread critical to extremely critical fire weather conditions to many areas of Los Angeles and Ventura counties Monday into Wednesday. This will be a PARTICULAR DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of a strong offshore pressure gradient (LAX-Daggett peaking at -8 to -9 mb), strong cold air advection, and moderate upper level wind support. As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, there is high confidence for a long duration Red Flag event. In addition, there is high confidence of of PDS Red Flag Warning conditions late Monday evening through Tuesday, as damaging wind gusts of 60 to 80 mph will likely overlap with single digit humidities across many of the windier mountain and foothills areas, and with gusts of 40 to 65 mph across most wind prone coastal and valley areas of Los Angeles and Ventura counties. With the threat of damaging wind gusts in these windier corridors, there will be an increased risk for downed trees and powerlines, along with power outages. The hardest hit areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando), and the hills above Camarillo into east Ventura. Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior (including long range spotting). As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires. Dry offshore conditions will likely persist into Thursday. * WINDS...Santa Ana winds expected to increase sharply late Monday morning or afternoon, then peak Monday night into Tuesday, when speeds of 20 to 30 mph with gusts of 35 to 55 mph will likely be common. Offshore winds are expected to diminish some on Wednesday, with gusts mostly in the 20 to 35 mph range. * RELATIVE HUMIDITY...Humidities are expected to lower to around 15 percent in many areas by Monday afternoon or early evening, with widespread humidities of 5 to 10 percent likely from late Monday evening into Tuesday, and persisting into Wednesday, with isolated readings as low as 2 percent likely. * IMPACTS...If fire ignition occurs, conditions are favorable for very rapid fire spread, extreme fire behavior, and long range spotting, which would threaten life and property. There is also the risk of locally damaging winds including trees and power lines.

Red Flag Warning issued December 8 at 4:04PM PST until December 11 at 6:00PM PST by NWS Los Angeles/Oxnard CA

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SANTA MONICA MOUNTAINS/ SANTA CLARITA VALLEY/ VENTURA COUNTY COASTS AND VALLEYS/ WESTERN SAN FERNANDO VALLEY -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THESE SAME AREAS... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 AM WEDNESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: SANTA SUSANA MOUNTAINS-- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY IN THIS SAME AREA... ...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 2 PM TUESDAY DUE TO DAMAGING SANTA ANA WINDS AND VERY LOW HUMIDITIES FOR THE FOLLOWING AREAS: VENTURA COASTAL PLAIN (ESPECIALLY FOOTHILLS)/ MALIBU COAST -- AND RED FLAG WARNINGS IN EFFECT FOR ALL OTHER TIMES FROM 2 PM MONDAY UNTIL 2 PM WEDNESDAY IN THESE SAME AREAS... ...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY UNTIL 6 PM WEDNESDAY FOR VENTURA MOUNTAINS, I5 CORRIDOR, EASTERN SAN FERNANDO VALLEY, AND SAN GABRIEL VALLEY DUE TO GUSTY SANTA ANA WINDS AND VERY LOW HUMIDITIES... ...RED FLAG WARNING IN EFFECT FROM 10 PM MONDAY UNTIL 10 PM TUESDAY FOR THE SAN LUIS OBISPO COUNTY MOUNTAINS DUE TO GUSTY EAST TO SOUTHEAST WINDS AND VERY LOW HUMIDITIES... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR MANY AREAS OF LOS ANGELES AND VENTURA COUNTIES *** A strong, widespread, and long duration Santa Ana event will bring widespread critical to extremely critical fire weather conditions to many areas of Los Angeles and Ventura counties Monday into Wednesday. This will be a PARTICULAR DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of a strong offshore pressure gradient (LAX-Daggett peaking at -8 to -9 mb), strong cold air advection, and moderate upper level wind support. As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning into afternoon, then peak Monday night into Tuesday. Offshore winds are expected to diminish some by Wednesday, but very dir will persist. With the strong likelihood of widespread single digit humidities with this event, there is high confidence for a long duration Red Flag event. In addition, there is high confidence of of PDS Red Flag Warning conditions late Monday evening through Tuesday, as damaging wind gusts of 60 to 80 mph will likely overlap with single digit humidities across many of the windier mountain and foothills areas, and with gusts of 40 to 65 mph across most wind prone coastal and valley areas of Los Angeles and Ventura counties. With the threat of damaging wind gusts in these windier corridors, there will be an increased risk for downed trees and powerlines, along with power outages. The hardest hit areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando), and the hills above Camarillo into east Ventura. Due to the expected long duration of dangerous fire weather conditions and critically dry fuels, there is the increasing potential for any new ignitions to have very rapid fire spread and extreme fire behavior (including long range spotting). As a result, there is the increasing threat for fire weather conditions to rival other historical fires in recent times including the Mountain and Thomas Fires. Dry offshore conditions will likely persist into Thursday. * A particularly dangerous situation exists for these areas due to the combination of damaging winds, single digit humidities, and extremely dry vegetation. Any new fire ignitions in this area will have dangerous fire spread with a significant threat to life and property. * WINDS...Santa Ana winds expected to increase sharply late Monday morning into afternoon, then peak Monday night into Tuesday. when speeds of 25 to 40 mph with gusts of 40 to 65 mph common across coastal and valley areas. Some of the windier foothills and mountains will likely see wind speeds of 30 to 50 mph with damaging wind gusts in the 60 to 80 mph range during the peak of the event Monday night into Tuesday. Some of the highest wind areas will likely be the San Gabriels, Santa Susanas, western Santa Monicas into Malibu, Ventura county valleys (especially Simi Valley and Moorpark), and western San Fernando Valley (especially Highway 118/210 corridors from Porter Ranch to San Fernando). Offshore winds are expected to diminish some by Wednesday. * RELATIVE HUMIDITY...Humidities are expected to lower to around 15 percent in many areas by Monday afternoon or early evening, with widespread humidities of 5 to 10 percent likely later Monday evening into Tuesday, and persisting into Wednesday, with isolated readings as low as 2 percent likely. * IMPACTS...If fire ignition occurs, conditions are favorable for large fires with very rapid fire spread, extreme fire behavior, and long range spotting, which would threaten life and property. There is also the risk of damaging winds including downed trees and power lines, as well as power outages.

Wind Advisory issued December 8 at 1:41PM PST until December 10 at 4:00PM PST by NWS Las Vegas NV

* WHAT...North winds 20 to 30 mph with gusts up to 45 mph expected in the Colorado River Valley. * WHERE...Lake Mead National Recreation Area, Lake Havasu and Fort Mohave, and San Bernardino County-Upper Colorado River Valley. * WHEN...From 10 AM PST /11 AM MST/ Monday to 4 PM PST /5 PM MST/ Tuesday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. * ADDITIONAL DETAILS...The strongest winds will occur between Cottonwood Cove and Lake Havasu.

Frost Advisory issued December 8 at 12:39PM PST until December 9 at 9:00AM PST by NWS San Francisco CA

* WHAT...Temperatures as low as 32 will result in frost formation. * WHERE...Southern Salinas Valley/Arroyo Seco and Lake San Antonio. * WHEN...From midnight tonight to 9 AM PST Monday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Cold Conditions can lead to hypothermia with prolonged exposure. * ADDITIONAL DETAILS...The coldest temperatures between 32 to 35 degrees will be observed in the far southern Salinas Valley and Fort Hunter Liggett area. Areas around and to the north of King City will be warmer with lows between 36 to 38 degrees anticipated.

Red Flag Warning issued December 8 at 11:52AM PST until December 11 at 4:00AM PST by NWS San Diego CA

...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY TO 4 AM PST WEDNESDAY FOR STRONG GUSTY SANTA ANA WINDS AND LOW RELATIVE HUMIDITY IN ALL MOUNTAIN AREAS, THE INLAND EMPIRE, SAN DIEGO COUNTY VALLEYS, AND INLAND ORANGE COUNTY... * WINDS...Northeast and east winds 20 to 30 mph. Gusts in the valleys 35 to 50 mph. Wind gusts 50 to 65 mph in the mountains and passes. Isolated gusts to 70 mph possible on Tuesday in wind prone locations in the mountains. Winds will be strongest in east-west oriented passes, such as the San Gorgonio Pass and San Diego County mountains and foothills. * RELATIVE HUMIDITY...As low as 7 percent. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. Outdoor property may be damaged along with difficult driving conditions in the wind. * LOCATION...San Bernardino and Riverside County Valleys-The Inland Empire, San Diego County Inland Valleys, San Bernardino County Mountains-Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest, Riverside County Mountains-Including The San Jacinto Ranger District Of The San Bernardino National Forest, Santa Ana Mountains-Including The Trabuco Ranger District of the Cleveland National Forest, San Diego County Mountains- Including The Palomar And Descanso Ranger Districts of the Cleveland National Forest and San Gorgonio Pass Near Banning.

Red Flag Warning issued December 8 at 11:52AM PST until December 11 at 4:00AM PST by NWS San Diego CA

...RED FLAG WARNING IN EFFECT FROM 10 AM MONDAY TO 4 AM PST WEDNESDAY FOR STRONG GUSTY SANTA ANA WINDS AND LOW RELATIVE HUMIDITY IN ALL MOUNTAIN AREAS, THE INLAND EMPIRE, SAN DIEGO COUNTY VALLEYS, AND INLAND ORANGE COUNTY... The National Weather Service in San Diego has issued a Red Flag Warning for strong gusty Santa Ana winds and low relative humidity, which is in effect from 10 AM Monday to 4 AM PST Wednesday. * WINDS...Northeast 20 to 30 mph. Gusts up to 40 mph, locally up to 50 mph east of Interstate 5. *RELATIVE HUMIDITY...As low as 10 percent. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. Outdoor property may be damaged along with difficult driving conditions in the wind. * LOCATION...Orange County Inland Areas.

High Wind Watch issued December 8 at 5:25AM PST until December 10 at 1:00PM PST by NWS Los Angeles/Oxnard CA

* WHAT...Northeast winds 25 to 35 mph with gusts up to 60 mph possible. * WHERE...Central Ventura County Valleys, Eastern Santa Monica Mountains Recreational Area, Ventura County Beaches, Ventura County Inland Coast, and Western San Fernando Valley. * WHEN...From Monday evening through Tuesday afternoon. * IMPACTS...Damaging winds could blow down trees and power lines. Widespread power outages are possible. Travel could be difficult, especially for high profile vehicles.

High Wind Watch issued December 8 at 5:25AM PST until December 11 at 12:00PM PST by NWS Los Angeles/Oxnard CA

* WHAT...Northeast winds 30 to 40 mph with gusts up to 65 mph possible. * WHERE...Calabasas and Agoura Hills, Santa Clarita Valley, Santa Susana Mountains, Southeastern Ventura County Valleys, Western San Gabriel Mountains and Highway 14 Corridor, and Western Santa Monica Mountains Recreational Area. * WHEN...From Monday afternoon through Wednesday morning. * IMPACTS...Damaging winds could blow down trees and power lines. Widespread power outages are possible. Travel could be difficult, especially for high profile vehicles.

Air Quality Alert issued December 7 at 9:18AM MST by NWS Phoenix AZ

The Imperial County Air Pollution Control District has declared a mandatory wood burning curtailment for residents within the Calexico area for Sunday, December 8, 2024. The declaration of a Mandatory curtailment, when forecast indicate elevated levels of fine particulate air pollution in the region, is issued to protect the public health. Smoke from wood burning can cause health problems. Breathing high levels of pollution from wood smoke can cause breathing problems (including asthma attacks), worsened lung and heart disease symptoms, and may even increase emergency room visits and hospitalizations. The Mandatory Curtailment rule prohibits the operation of any wood burning appliances during the curtailment period. This prohibition does not apply to cookstoves and those devices exclusively gaseous- fueled. To view current and forecast air quality within Imperial County visit the Imperial County Air Quality website at http://www.imperialvalleyair.org/ or follow ICAPCD on Twitter, facebook or Instagram (@county_air)