Fire Weather Watch 12/29/2024 14:20 for California areas

...RED FLAG WARNINGS IN EFFECT TUESDAY INTO WEDNESDAY FOR PORTIONS OF THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS AND VALLEYS DUE TO GUSTY NORTH TO NORTHEAST WINDS AND LOW HUMIDITY, WITH FIRE WEATHER WATCHES IN EFFECT WEDNESDAY NIGHT INTO THURSDAY... ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM TUESDAY INTO THURSDAY FOR THE VENTURA/MALIBU COASTS DUE TO GUSTY NORTH TO NORTHEAST WINDS AND LOW HUMIDITY... .The weather pattern this week is expected to become favorable for elevated to critical fire-weather conditions across Santa Ana wind-prone areas of Los Angeles and Ventura Counties, as well as portions of Santa Barbara County prone to north-wind enhancements. This week, an upper-level ridge is forecast to gradually build along the Pacific coast to the west of a large upper trough encompassing much of the central and eastern states. Correspondingly, surface high pressure strengthening over the Great Basin will facilitate increasing offshore flow amid slight upper level wind support, which will combine with unseasonably warm temperatures assisted by the building upper ridge to produce the increased fire-weather risk. LAX-Bakersfield offshore gradients are currently forecast to reach 5-7 mb starting Monday, with LAX- Daggett offshore gradients reaching 4-5 mb starting Tuesday. Given the enhanced northerly pressure gradients, wind directions could be 10-20 degrees more northerly than easterly for this event compared to other November and December 2024 events, especially early on for this next event. Areas with highest confidence of reaching Red Flag thresholds have been upgraded to Red Flag Warnings for the Tuesday into Wednesday time period. With less confidence in the strength of offshore winds Wednesday night into Thursday, this time frame has been kept as a Fire Weather Watch for now. In addition, there is still some uncertainty in the strength and duration of offshore winds for the coastal areas of Ventura county, Malibu, and central Ventura valleys (including the Highway 126 corridor from Santa Paula to Piru), resulting in a continuation of the Fire Weather Watch for these areas. Regarding alternate scenarios, there is a 30-40% chance for fire- weather headlines to be expanded to include the eastern San Gabriels, northwest Los Angeles County Interstate-5 corridor, and northern Ventura County mountains. In addition, the enhanced northerly gradients may tend to expand the fire-weather risk to the east of areas more typically prone to a moderate Santa Ana wind event, to also include areas from Hollywood to Beverly Hills and Santa Monica -- Confidence: lower chance at 30-40% for fire- weather headlines. Elevated to brief critical fire-weather conditions will also be a concern farther west across the San Luis Obispo County and Santa Barbara County mountains and foothills, especially including the Santa Ynez range when northerly pressure gradients are strongest on Monday and Tuesday, though humidities will likely remain elevated -- Confidence: even smaller but non- zero chance at 20% for fire-weather headlines. * WINDS...North to northeast winds 15 to 25 mph with gusts to 35 mph, diminishing to 10 to 20 mph with gusts to 25 mph by Wednesday. Strongest winds near Malibu. * RELATIVE HUMIDITY...Relative humidities 10 to 20 percent Tuesday decreasing to 7 to 15 percent in Malibu by Wednesday and Thursday. * IMPACTS...If fire ignition occurs, conditions are favorable for rapid fire spread and extreme fire behavior which would threaten life and property.