San Geronimo 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 San Geronimo.

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

Fire Weather Watch issued December 6 at 9:13PM PST until December 11 at 4:00AM PST by NWS San Diego CA

...FIRE WEATHER WATCH IS IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY NIGHT FOR STRONG GUSTY SANTA ANA WINDS AND LOW RELATIVE HUMIDITY IN ALL MOUNTAIN AREAS, THE INLAND EMPIRE, AND THE SAN DIEGO COUNTY PORTIONS OF THE SAN DIEGO VALLEYS... * WINDS...Northeast and east winds 20 to 30 mph. Gusts in the valleys 25 to 40 mph, locally up to 60 mph in mountains and passes. Highest winds in San Gorgonio Pass and San Diego County mountains and foothills. * RELATIVE HUMIDITY...5 to 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. * 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.

Dense Fog Advisory issued December 6 at 9:00PM PST until December 7 at 12:00PM PST by NWS Hanford CA

* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Across the San Joaquin Valley from Merced County to Kern County * WHEN...Until noon PST Saturday. * IMPACTS...Low visibility could make driving conditions hazardous.

Wind Advisory issued December 6 at 7:30PM PST until December 7 at 10:00AM PST by NWS Los Angeles/Oxnard CA

* WHAT...Northeast winds 20 to 30 mph with gusts up to 50 mph expected. * WHERE...Santa Susana Mountains. * WHEN...From 2 AM to 10 AM PST Saturday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

Freezing Fog Advisory issued December 6 at 3:25PM PST until December 7 at 10:00AM PST by NWS Reno NV

* WHAT...Visibility one quarter mile or less in freezing fog. * WHERE...In California, Lassen-Eastern Plumas-Eastern Sierra Counties. In Nevada, Northern Washoe County. * WHEN...Until 10 AM PST Saturday. * IMPACTS...Low visibility could make driving conditions hazardous. Some roadways may also be icy and slippery during the early morning hours Saturday. * ADDITIONAL DETAILS...Localized areas of freezing fog may still persist through Saturday evening.

Fire Weather Watch issued December 6 at 1:26PM PST until December 11 at 6:00PM PST by NWS Los Angeles/Oxnard CA

...FIRE WEATHER WATCH IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA COUNTIES 10 AM MONDAY UNTIL 6 PM WEDNESDAY DUE TO MODERATE TO LOCALLY STRONG SANTA ANA WINDS AND VERY LOW HUMIDITIES... .As surface high pressure builds into the Great Basin, Santa Ana winds are expected to increase late Monday morning or afternoon, then peak Monday night into Tuesday night. Offshore winds are expected to persist some by Wednesday, but very dir will persist. With the strong likelihoold of widespread single digit humidities with this event, confidence is increasing for a long duration Red Flag event. In addition, there is the potential for a high end Red Flag event across some of the windiest areas Monday night through Tuesday night, as localized wind gusts of 50 to 65 mph could overlap with single digit humidities across the western San Gabriels, Santa Susanas, and western Santa Monicas. The National Weather Service in Los Angeles/Oxnard has issued a Fire Weather Watch for gusty Santa Ana winds and very low relative humidity, which is in effect from late Monday morning through Wednesday afternoon. * WINDS...Santa Ana winds expected to increase sharply late Monday morning or afternoon, then peaking Monday night through Tuesday night when speeds of 20 to 35 mph with gusts of 35 to 50 mph will likely be common, including typical wind prone coastal areas. Isolated gusts as high as 55 to 65 mph during peak in the windiest locations, such as the western San Gabriels, Santa Susanas, and western Santa Monicas. Offshore winds expected to diminish some on Wednesday. * RELATIVE HUMIDITY...Humidities are expected to lower to around 15 percent in many areas by Monday afternoon, with widespread humidities of 5 to 10 percent likely from Monday night or Tuesday and persisting into Wednesday, with isolated readings as low as 3 percent possible. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property.