Gusty winds over the mountains and deserts and light precipitation in the coastal basin expected this afternoon into early Wednesday morning. Thursday will be a little warmer and dry with weaker winds. Cooler conditions likely this weekend, with periods of increased winds and another round of light precipitation west of the mountains.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
.New Aviation and Marine Discussion,
A trough of low pressure is expected to move east across Central California today into Wednesday. Visible satellite at 11 AM was showing clouds moving into Orange County, clouds are expected to spread south and east across the area. Additionally, areas of light rain will spread south and east across the area this afternoon and evening. Accumulations of 0.10" or less are expected in the coast and valleys, with totals up to 0.25" on the coastal slopes of the mountains. The San Bernardino County mountains are the most likely place to see accumulations up to 0.25". Rainfall rates are expected to be 0.10" or less per hour. Dry conditions will return by mid- Wednesday morning.
Southwest to west winds have already started to weaken, with gusts to 45 mph being observed through the San Gorgonio Pass at 11 AM. Winds will peak in strength this evening. Strongest winds will be over the mountains and into the deserts. Peak gusts of 40 to 60 mph expected, with a few isolated gusts to 65 mph on the northern slopes of the San Bernardino mountains. Winds will decrease through the day Wednesday with gusts mainly 35 to 45 mph, locally up to 55 mph through wind prone passes like the San Gorgonio Pass.
Dry and warmer conditions expected on Thursday. Highs along the coast will be a few degrees warmer, with inland locations up to 7 degrees warmer than Wednesday. The temperature increase will bring conditions near to slightly above normal for this time of year. Another area of low pressure looks likely to move across the US West Coast for the upcoming weekend. While there remains some timing differences between the global models, the trough will bring another round of cooler conditions, increase in westerly winds, and potential for light precipitation. Dry and warmer for next Monday, with high temperatures for inland areas still a few to around 5 degrees below average.
220000z, Coast/Valleys, A band of low clouds is currently moving into western portions of the coastal basin. Generally VFR conditions expected with bases 3-5 kft. However, ISO -SHRA could briefly create MVFR vis and cigs 1500-2500 ft MSL from now through 04z Wed as they pass over sites. Clouds mostly scatter out from northwest to southeast after the band, though patchy BKN cigs around 3-5 kft may linger through the overnight hours, particularly in San Diego County. Otherwise, strong low-level winds will allow for moderate up/downdrafts to persist downwind of the Santa Ana mtns (i.e KRAL, KSBD) through early Wednesday morning.
Mountains/Deserts, Strong southwest to west winds are currently gusting 35-45 kts widespread with local gusts to 55 kts through passes and along desert slopes. Isolated vis reduced by BLDU in the deserts and moderate/strong up/downdrafts in lee of mountains. Winds decrease slowly after 06z, but remain breezy for the desert slopes and mtn passes. Winds strengthen again Wednesday afternoon, though not as strong as today with gusts 25-35 kts, locally 40 kts through passes and along desert slopes.
Westerly to northwesterly winds will increase Wednesday afternoon through late Wednesday night with gusts 20-25 knots likely for outer coastal waters. These winds could generate choppy and hazardous conditions. More details can be found in the Small Craft Advisory. Winds diminish early Thursday morning before briefly increasing again in the outer coastal waters Thursday afternoon, with peak gusts around 20 knots. Otherwise, no hazardous marine conditions are expected through Saturday.
Ca, Wind Advisory until 7 AM PDT Wednesday 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, Small Craft Advisory from 3 PM Wednesday to 3 AM PDT Thursday for Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.
