A cooling and drying trend will occur across the region into the weekend and early next week. This will be accompanied by a building marine layer with clouds returning closer to the coastal areas each night and morning. An area of high pressure may strengthen by the end of next week, nudging temperatures back above average.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
High pressure continues to weaken over the region today with stronger onshore flow seen at current observations. This has allowed for a deepening marine layer, where some places along the coast saw low clouds and patchy fog earlier this morning. Looking toward the lunch hour, temperatures a relatively cooler with highs in the 70s to near 90 west of the mountains. Elevated westerly winds will also be felt across the mountains and deserts with wind gusts 20-40 MPH.
An area of low pressure off the west coast of British Columbia will continue to push southward today, eventually moving into the Pacific Northwest this weekend. This weather pattern will help bring in more cooler air and greater extent to the marine layer into far western valleys. We can expect to cool a few degrees each day with breezy westerly winds across the mountains and deserts each afternoon and evening. Temperatures will be near average by the weekend, with highs dipping below average by next Monday and Tuesday. High temperatures may stay below 90 degrees for areas west of the mountains with highs closer to 100 degrees over the Coachella Valley. Low temperatures will also begin to cool off through early next week as well with lows in the 50s and 60s along and west of the mountains and up in the high desert.
High pressure over the Southern Plains may expand further into the desert southwest by the end of next week. The placement and strength of this system is still uncertain, but many models are hinting that another subtle warm up may take place by this time. Nbm shows highs approaching 100 across inland valleys with 70s and 80s closer to the coast and across the mountains.
121730z, Coasts, VFR through the late afternoon, though some low clouds near 1500 ft MSL may stick to the beaches. High confidence on low clouds returning to coastal TAF sites and up to 15 miles inland after 01Z Sun with bases 1200-1700 ft MSL. Low confidence on cigs making into the Inland Empire and VCTY KONT after 10z. Vis reductions most likely on higher coastal terrain. Scatter out Sunday similar to this morning near 16-18Z.
S/W winds gusting over 30 kts at times 20z Sat-06z across mountain passes into the deserts. Otherwise, FEW clouds above 15 kft and VFR conditions through Sunday.
West-northwest winds expected to gust up to 20 knots in the afternoons through Sunday over outer coastal waters. Otherwise, no hazardous marine conditions are expected through Wednesday.
Ca, None. PZ, None.
