Fire Weather Watch 01/06/2025 15:24 for California areas

...PARTICULARLY DANGEROUS SITUATION (PDS) RED FLAG WARNING IN EFFECT NOON TUESDAY UNTIL 4 PM WEDNESDAY DUE TO DAMAGING NORTH TO NORTHEAST WINDS AND LOW HUMIDITIES FOR THE FOLLOWING AREAS: SAN GABRIEL MOUNTAINS/ SAN GABRIEL AND SAN FERNANDO VALLEYS (ESPECIALLY FOOTHILLS)/ BEVERLY AND HOLLYWOOD HILLS/ COASTAL AREAS ADJACENT TO SEPULVEDA PASS / SANTA MONICA MOUNTAINS / SANTA SUSANA MOUNTAINS / MALIBU / EASTERN VENTURA VALLEY (MAINLY NEAR SIMI VALLEY/MOORPARK) -- THIS WILL LIKELY BE A LIFE THREATENING, DESTRUCTIVE, AND WIDESPREAD WINDSTORM... ...RED FLAG WARNINGS IN EFFECT FOR LOS ANGELES COUNTY AND MUCH OF VENTURA COUNTY---SEE TIMINGS IN HEADLINES BELOW... ...RED FLAG WARNING IN EFFECT FOR SANTA BARBARA MOUNTAINS INCLUDING EASTERN SANTA YNEZ RANGE TUESDAY INTO WEDNESDAY... ***THIS IS A PARTICULARLY DANGEROUS SITUATION (PDS) FOR PORTIONS OF LOS ANGELES AND VENTURA COUNTIES!*** .A very strong, widespread, and destructive north to northeast windstorm will bring Extremely Critical fire weather conditions to many areas of Los Angeles and eastern Ventura counties Tuesday afternoon into early Wednesday afternoon. This is a PARTICULARLY DANGEROUS SITUATION (PDS) Red Flag Warning event in many areas, with the combination of very strong upper level wind support, tightening offshore pressure gradients (LAX-Daggett peaking at -7 to -8 mb), and moderate cold air advection. The strongest winds with this event are expected to be Tuesday afternoon into early Wednesday afternoon when widespread damaging wind gusts of 50 to 80 mph are likely. The San Gabriel mountains, Santa Susana mountains, and foothills of the San Gabriel/San Fernando Valleys will likely see areas of destructive wind gusts between 80 and 100 mph! Due to the very strong upper level wind support and high risk for strong mountain wave activity, typical wind sheltered areas such as portions of the LA basin and San Gabriel Valley. The strong winds will likely result in widespread downed trees/powerlines, as well as widespread power outages. THIS WILL LIKELY BE THE MOST DESTRUCTIVE WINDSTORM SEEN SINCE 2011 WINDSTORM THAT DID EXTENSIVE DAMAGE TO PASADENA AND NEARBY FOOTHILLS OF THE SAN GABRIEL VALLEY. ANY COMMUNITIES ALONG HIGHWAY 118 AND 210 CORRIDORS WILL BE AT HIGHEST RISK FOR COMPARABLE WIND DAMAGE. Humidity levels are also expected to lower to between 10 and 15 percent in many areas by Tuesday afternoon/evening, potentially lowering into single digits in some areas by late Tuesday night into Wednesday. The offshore winds are now expected to arrive early Tuesday morning, resulting in the Red Flag Warning area being moved up to 4 am Tuesday in many areas. AREAS IN A RED FLAG WARNING (ESPECIALLY DURING THE PDS TIME FRAME) WILL HAVE INCREASED RISK FOR LARGE FIRES WITH VERY RAPID FIRE SPREAD, EXTREME FIRE BEHAVIOR, AND LONG RANGE SPOTTING. While the longer duration of strong winds and Red Flag conditions is expected to be focused across Los Angeles and Ventura counties, there is now expected to be a shorter duration of Red Flag conditions across the mountains of Santa Barbara county Tuesday into Wednesday. Long duration Red Flag Warnings are in effect for much of Los Angeles and Ventura counties Tuesday through Thursday, with Fire Weather Watches in effect Thursday night into Friday. ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR POTENTIAL WEAK TO MODERATE OFFSHORE WINDS AND LOW RELATIVE HUMIDITY FOR MUCH OF LOS ANGELES AND VENTURA COUNTIES... * WINDS...Strong/damaging north to northeast winds Tuesday into Wednesday, likely peaking in many areas between Tuesday afternoon and Wednesday morning when there is the potential for strong mountain wave wind activity. During this peak, sustained winds of 35 to 50 mph and widespread damaging gusts of 50 to 70 mph can be expected. Moderate north to northeast winds will likely persist Thursday with gusts of 30 to 50 mph, with some weakening possible by Friday. * RELATIVE HUMIDITY...Humidities 20 to 30 percent early Tuesday morning, falling to 10 to 20 percent by late Tuesday afternoon/evening. Humidities will potentially fall to single digits in some areas from Wednesday into Friday. * IMPACTS...If fire ignition occurs, conditions are favorable for very rapid fire spread and extreme fire behavior, including long range spotting, which would threaten life and property. There will be a high risk for widespread downed trees and powerlines, as well as widespread power outages.