Near average temperatures today with below average temperatures expected Monday through midweek. Low clouds will spread into the valleys each night and morning, lingering into the afternoon at times along the coast. Increased westerly winds expected Tuesday through potentially Thursday for the mountains and deserts. Patchy drizzle or light rain possible west of the mountains each night and morning from Monday night through Thursday morning.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Low clouds in the coastal basin are making their retreat to the coast with clearing skies behind and to the east of the mountains. Clearing at the coast will be short lived with the marine layer expected to move back in later this afternoon and once again filling into the coastal basin late tonight into the early Monday morning. High temperatures will be near to just below the seasonal average as an upper level low moves from just off the coast and to the east Monday.
As low pressure decreases at the surface through Thursday, temperatures will continue to cool and the marine layer will deepen. This will increase chances for patchy drizzle west of the mountains beginning Monday night through Thursday morning and bring daily highs 10-15 degrees below average for the Inland Empire, mountain areas, and deserts by Thursday afternoon.
An upper level trough is expected to slide down the coast Tuesday through Thursday before moving out to the northeast Friday. This trough will produce gusty onshore winds in the mountains and deserts, especially in the desert mountain slopes and passes. The strongest winds are expected Tuesday and Wednesday in the afternoons evenings with wind gusts around 35-55 mph in desert areas, with isolated gusts up to 60 mph through the passes.
Temperatures will begin to increase Friday, reaching near the seasonal average by the weekend.
241730z, Coast/Valleys, Inland valleys clear through 20Z Sun, with coastal locations seeing partial or intermittent clearing after 20Z. Clouds with bases 2000-2500 ft MSL, locally down to 1500 ft MSL begin to spread inland after 00z Mon, filling in the coastal basin by 10Z Mon. The locations that are most likely to see bases below 2000 ft are near mountain foothills and far inland valleys (70-80 percent chance of occurrence). Low clouds expected to clear 18-20Z Mon, with only partial and intermittent clearing along the coast.
Deserts, Mostly clear with VFR conditions.
Westerly winds could gust near 21 kt Tuesday and Wednesday afternoon in evening in the outer coastal waters by San Clemente Island. Otherwise, no hazardous marine conditions are expected through Friday.
Ca, Wind Advisory from 3 PM Tuesday to 5 AM PDT Thursday for Riverside County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.
Wind Advisory from 3 PM Tuesday to midnight PDT Tuesday night for Apple and Lucerne Valleys.
PZ, None.
