The storm that brought showers and a few thunderstorms to southern California is east of the state today. Post-storm winds diminished last night as expected, but I was surprised to see gusty winds on campus this morning. Northwesterly winds appeared to squirt from the Tehachapi Mountains, pass through the San Fernando Valley, and finally reach the Westside. Upper air support for the wind, which was underpredicted by the numerical models yesterday, should wane through the day. However, the afternoon sea breeze in the coastal plain may provide some breezy weather later today (shouldn't be as strong as earlier winds though). I'm not expecting significant wind tonight.
In spite of the sunnier weather today, daytime temperatures shouldn't get much warmer than it got yesterday. A cool, northwesterly, wind flow pattern exists today (reason for noticeably cooler morning today where the wind didn't stir up the air). Little change is expected tomorrow although inland areas may see slightly higher temperatures (on-shore flow should be a bit weaker tomorrow morning than today).,
A new storm is nearing the northwest corner of the state today. Wet weather will spread across northern California tonight into tomorrow. Rain should reach San Luis Obispo County by tomorrow night. Most models show the storm weakening considerably before reaching L.A. County. There remains some uncertainty about whether widespread, wet weather will reach our County. While today's model consensus supports wet weather early Saturday (mostly before sunrise in L.A. County)., I'm not confident enough to word the forecast as "showers likely". In any case, the storm should be minor (no thunderstorm threat with this storm). Any rainfall in the County should be under a tenth inch (mountains might get as much a quarter inch rain...snow levels should remain above 7000 feet for most of the period...only trace amount snowfall at resort level).
Another storm is predicted to reach the Southland Monday morning, but many model solutions favor an "inside slider" type trough (more wind than wet weather). I wouldn't rule out some instability showers (mostly around the mountains), but most areas shouldn't remain dry. Widespread, breezy amd sunnier weather should prevail by Monday afternoon.
Some model solutions show a large, "cut-off" low pressure forming somewhere over the Southwest by Tuesday. Depending on its strength and proximity to the Southland, there is some chance for cold air, instability showers (mostly around the mountains/desert region). Breezy weather may occur over parts of the Southland, and temperatures would remain below normal. Even if the "cut-off" low pressure winds up well to the east, a predicted, "inside slider" trough next Thursday (30th) should limit warming early next week (at best, slight warmer than normal on Tuesday/Wednesday). This predicted trough should be just a wind storm for southern California (no relevant threat of showers even over the mountains).. However, the high pressure that follows may promote a few days of warmer normal weather (end of next week). How warm it gets remains to be seen (quite a bit of variability with model solutions).
UCLA Forecasts and analyses are written by James Murakami
– posted: 2017-03-23