Periods of light to locally moderate precipitation expected through Monday, most widespread today. Dry conditions return Tuesday and will prevail through the rest of the week. Periods of breezy winds expected in the afternoons and evenings through Monday and again mid- week. Near to below average temperatures expected for much of this week with warmer conditions this weekend.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Evening update, Showers have become more isolated and lighter this evening, with most of the activity across San Diego County. This is expected to continue overnight as the initial short wave lifts northeast out of the area. Snow levels currently around 6500-7000 ft will drop to around 5000-5500 Monday morning, then rise to 5500-6000 ft Monday afternoon. Any snow accumulation will be one inch or less below 7000 ft. A second low, currently near Eureka, will drop south and amplify tonight, becoming a closed low over California by Monday afternoon. This next wave will interact with residual deep boundary layer moisture to produce another round of scattered showers and a slight (10%) chance of thunderstorms as cold air aloft moves overhead Monday afternoon. Additional rain accumulations will range from 0 to 0.20" for the coasts/valleys, 0.05-0.30" for the mountains, locally up to 0.50" on the west facing coastal slopes, and less than 0.05" in the deserts. Isolated higher amounts are possible where heavier showers/thunderstorms develop. Otherwise southwest to west winds gusting 30-40 mph on the desert mountain slopes and through the passes continue at times through Monday night, strongest during the afternoons and evenings.
Previous discussion, Cooler and dry conditions with weaker winds expected on Tuesday. Another trough of low pressure is expected to dig into the Pacific Northwest sometime Wednesday into Thursday. The broad troughing pattern will keep temperatures near to slightly below average for most locations and increase westerly winds in the mountain and desert again. This low is expected to stay inland, which will keep us dry and bring chances for Santa Ana winds for the end of the week. Weak ridging combined with offshore flow is expected to bring warmer conditions to the area next weekend.
130400z, Coasts/Valleys, SCT-BKN low clouds based 3000-6000 ft MSL over the coastal basin will remain in place through tonight. Generally VFR conditions through 12z Mon with coverage of -SHRA remaining isolated at best. Thereafter, a slight uptick in shower activity is expected, especially in San Diego County. Intermittent MVFR cigs/vis in -SHRA/SHRA. Shower activity decreases again from north to south from 18z Mon-00z Tue. BKN low clouds based 3000-5000 ft return to San Diego County after 03z Tue with bases lowering slightly overnight.
Mountains/Deserts, West to southwest winds gusting 25-40 kts currently through mountain passes, along deserts slopes and locally into the deserts. Winds will continue to weaken slowly through tonight but remain elevated with occasional gusts 20-25 kts along the desert floor and gusts to 35 kts along slopes and through passes. Winds strengthen again after 21z Mon with gusts 25-40 kts. Isolated SHRA/SNSH activity will continue along coastal slopes through Monday morning with an uptick in shower coverage Monday afternoon. FG through the period where clouds intersect terrain.
Otherwise, current satellite indicates mountain waves are present through most of the Inland Empire and deserts. Mod up/downdrafts expected through at least Monday morning in lee of mtns.
Northwest winds will briefly strengthen again for outer coastal waters Monday afternoon and evening with gusts 15 to 20 kts. Choppy seas may create hazardous conditions.Otherwise, no hazardous conditions expected through Friday.
Ca, None. PZ, None.
