Southwest to west winds for the mountains and deserts will gust to 40 to 50 mph this evening, weakening and turning offshore tonight. Gradually warmer and dry weather with periods of weak offshore flow Monday through Wednesday. Continued warming inland through Thursday, then slow cooling into next weekend. The marine layer will be shallower Tuesday through the reminder of the week with less extensive night and morning low clouds.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Evening update,
Gusty onshore winds and pockets of blowing dust in the deserts continue. Whitewater recorded the highest wind gust of 69 mph at 550 PM. A list of peak wind gusts is headlined on our website at weather.gov/sgx. A cold front moving in from the north has kicked up plenty of dust across NV and into the Owens Valley. This dust storm has progressed southward behind the front through the afternoon and is forecast to arrive in our portion of the Mojave Desert later this evening. So far visibility at the few and far between ASOS sites in northern San Bernardino County have only dropped to about 3 miles. Not anticipating visibility to lower enough for a dust advisory or dust storm warning, but those traveling on I-15, Highway 395, or other routes in the Mojave desert should be prepared for sudden reductions in visibility and gusty winds.
For the coastal and valley areas, a deep marine layer remains in place. High-res guidance continues to show light precipiation west of the mountains tonight (mainly in San Diego County), so introduced light drizzle into the forecast. Winds turn offshore as the aforementioned front continues to shift south, which will help clear out marine layer clouds and end any light precip by mid- morning Monday. Otherwise light smoke possible at times west of the mountains due to the Santa Rosa Island Fire in the Channel Islands.
Previous discussion,
(today through tomorrow night), Gusty winds will continue through the day today and through this evening as low pressure brings winds from the west over the area. As low pressure shifts further east, winds will ease through Monday. Strongest winds are in the deserts, desert mountain slopes and mountain passes with gusts up to 45 to 55 mph, locally up to 60 mph.
Highs today and Monday will be near to just below average for much of the area. The exception being some areas in the Riverside and San Bernardino county mountains with highs 5 to 10 degrees below average.
Low clouds from the marine layers influence will stick around through the day today and are expected to clear Monday morning.
(Tuesday through Sunday), As winds shift to off shore Tuesday, low clouds will stick closer to the coast, giving us some much needed sunshine in the afternoons at least through mid-week. Temperatures increase area wide Tuesday, with daily highs continuing to increase through the week, peaking Thursday afternoon. Temperatures Thursday will be up to 5 degrees warmer than average over most of the area. The high deserts will see temperatures 5-10 degrees above average.
180600z, Coast/Valleys, Clouds with varying bases 2000-4000 ft MSL in place across the entire coastal basin this evening, but drier air moving in and the development of offshore winds should help clear out much of the cloud cover by sunrise. A majority of the lower clouds with MVFR CIGs are focused across the coastal areas, though CIGs will likely be intermittent through the next several hours. Guidance is consistent in that a bulk of the cloud cover will grow more and more patchy after 09z, with nearly full clearing by 15-18z. Onset northerly offshore winds through the Cajon Passes around 09- 12z, with some BLDU from the deserts sneaking through below the pass as well. Winds remaining onshore at the coasts, with onshore flow resuming into the inland valleys by Monday afternoon. Low confidence in the return of marine layer clouds Monday evening, but will likely not occur until after 03z Tuesday.
Mountains/Deserts, Gusty onshore winds from earlier today have largely fallen below 25 knots at this hour. A backdoor front bringing offshore northerly winds is currently pushing southward through San Bernardino County. Accompanying this front is 25-35 knot northerly wind gusts, along with blowing dust which may bring visibilities down to 2-5 SM. BLDU and northerly gusts expected to reach the High Desert between 05-07z, and into the Coachella Valley by 06-09z. Wind gusts gradually decreasing overnight with improving visibility after the front passes.
No hazardous marine conditions expected through Friday.
A westerly swell from 290 degrees with a 9 to 10 second period is bringing elevated surf of 4 to 6 feet through Monday morning. Highest surf on west to northwest facing beaches. The combination of elevated surf and high tides of 6.5 to 7 feet will result in minor tidal overflow, especially for beach parking lots and boardwalks. Surf will start to decrease Monday afternoon.
Ca, Beach Hazards Statement through Monday morning for Orange County Coastal Areas-San Diego County Coastal Areas.
Wind Advisory until 3 AM PDT Monday for Apple and Lucerne Valleys-Riverside County Mountains-San Bernardino County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.
PZ, None.
