Thursday will be a little warmer and dry. Cooler with gusty onshore winds Friday through the weekend. Saturday evening into Sunday morning there is a chance of precipitation over and west of the mountains. Continued troughing aloft will continue slightly below average temperatures and windier conditions with chances of precipitation into the middle of next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Evening update, A few low clouds remain banked up against the mountains in San Diego County, otherwise skies are clear. The 00Z KNKX sounding shows the marine inversion is fairly weak, so expect any low clouds to remain patchy tonight. Gusty west winds continue across the mountains and deserts, strongest through the passes where gust are currently 40-50 mph. Winds gradually weaken through the night tonight, briefly turning northerly Thursday morning. Warmer across the area on Thursday as the upper low moves east with high temperatures returning to near normal for late April. Warming continues on Friday in the mountains and deserts, with little change west of the mountains.
Previous discussion, This weekend, an area of low pressure is expected to move across Central California. That will bring an increase in winds and potential for precipitation over and west of the mountains. Southwest to west winds will increase over the mountains and into the deserts Friday through Sunday, with strongest gusts expected on Saturday afternoon and evening. Peak gusts of 40 to 50 mph, locally up to 65 mph possible. Light precipitation is expected with the passage of this low, with the most likely time for any precipitation to be Saturday afternoon into Sunday morning. Overall, rainfall totals are expected to be on the lighter side. Nbm chances for rainfall to exceed 0.25" is 15-30% in the mountains and less than 10% elsewhere.
Dry and warmer conditions expected to return for next Monday, with high temperatures for inland areas still a few to around 5 degrees below average. Another disturbance moving through the mean flow is expected mid-week, which would keep conditions on the cooler side and increase winds and precipitation chances.
230430z, Coast/Valleys, Patchy low clouds based 2000-3000 ft MSL will continue to develop over San Diego County in the next few hours. Clouds become more confined to coastal areas after 09z and may spread into coastal Orange County, but coverage should remain patchy. Any remaining low clouds scatter by 12-15z. Otherwise, SCT- BKN high clouds AOA 20 kft expected from early Thursday morning through the afternoon. Low clouds will struggle to reform Thursday night with only a 20-30% chance of any development.
Mountains/Deserts, West winds will continue this evening with gusts 25-35 kts, locally 40 kts through passes and along desert slopes. Local up/downdrafts in lee of mountains and patchy BLDU reducing vis in the deserts. Winds will begin to ease around 12-15z Thursday.
West-northwest winds will continue to gust 20-25 kts in the outer waters through early Thursday morning, generating choppy and hazardous conditions. More details can be found in the Small Craft Advisory. No additional hazardous marine conditions are expected Thursday through Monday.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Thursday for Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.
