Cooler weather and a more extensive marine layer are expected through Saturday as low pressure aloft moves through the region. Areas of westerly winds through mountains and into deserts will be quite brisk each afternoon and evening. High pressure will build next week, bringing a warming trend and a diminished marine layer with less coastal cloud coverage.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Low clouds made it barely into the western and southern entrances of the Inland Empire this morning. Clouds have cleared to the beaches, but took their sweet time in Orange County. Weak low pressure aloft will gradually strengthen, which will enhance our onshore flow and allow the marine layer to deepen. That will extend the nocturnal coastal clouds farther inland for each night and morning into Saturday. Most of the coastal basin, including most inland valleys, should get some of the June cloud cover. Temperatures near normal today will dip below normal for Thursday through Saturday. The low pressure aloft forms a very weak June- like trough that moves through California Friday and Saturday. Westerly onshore winds through mountain passes and into deserts will be fairly strong, gusting to 35-45 mph each afternoon and evening. Top gusts in the wind-prone passes could exceed 50 mph. The trough and weakens Sunday to start a warming trend. High pressure over the Southwest will build and, according to some ensemble solutions, get very strong next week. Right now it's looking good for a substantial warming trend Monday through Wednesday, especially away from the coast. The marine layer and coastal cloud coverage will shrink under the weight of that ridge. Coverage should be restricted only near the coast during nights and mornings. Temperatures around Tuesday and Wednesday are likely to be up to 10 degrees above average, which would introduce a major heat risk to parts of the lower deserts.
171930z, Coast/Valleys, Patchy low clouds based 1700-1900 feet MSL will persist along the immediate coast this afternoon. These clouds will push ashore after 03Z and move into some inland valleys overnight. There is a 60% chance for clouds to make it into portions of the Inland Empire, including vcnty KONT, 12-16Z. Bases should lift to 1800-2000 feet MSL. Vis reduced to 3-5SM in valleys. Scatter out Thursday 16-18Z.
Mountains/Deserts, Mostly clear. Breezy westerly winds gusting 25- 35 kts through mountain passes and into deserts 19-06Z.
No hazardous marine conditions are expected through Sunday.
Elevated surf and strong rip currents continue through Friday. Surf of 3-5 feet with local sets to 7 feet are expected at south-facing beaches. Surf for southern San Diego County will be slightly lower, but hazardous swimming conditions with high rip current and longshore current risk will still exist. See the Beach Hazards Statement for more details.
Ca, Beach Hazards Statement through Friday evening for Orange County Coastal Areas-San Diego County Coastal Areas.
PZ, None.
