A low pressure system will approach the region, bringing cooler and breezier weather, along with a chance of light rainfall through Tuesday. A deepening marine layer could bring patchy drizzle to portions of the coastal areas and inland valleys again tonight into Monday morning. The best chance for light rain showers will be along and west of the mountains Monday evening into Tuesday morning. Dry and warmer weather is expected by Wednesday into next weekend.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
A cutoff low continues to tumble closer to the California coast today, bringing a deep marine layer, cooler weather and increased winds across the mountains and deserts. Winds are currently near 20-35 MPH across these regions and will increase this afternoon into the evening closer to 35-45 MPH. Winds look to continue to be gusty into the night with slightly higher winds by Monday afternoon and evening, where gusts will locally reach above 55 MPH in some mountain passes in the Riverside and San Diego Counties. High profile vehicles will see increased risk of incidents in windy conditions and blowing sand/dust.
The marine layer is around 5,000 feet thick, covering much of the coastal basin and even reaching into the top of the Cajon Pass. Clouds will partially clear areas this afternoon, but other areas will remain under the clouds throughout the day as the low clouds resurges back inland by later this afternoon/evening. Just like this morning, areas near the coast may see some marine layer drizzle/light showers overnight into Monday Monday morning as the marine layer remains quite saturated. The area of low pressure will move closer to the region by Monday into Tuesday, bringing an increased chance of light showers from the coast to the mountains. Hi-res models are in pretty fair agreement on the timing of the light showers to begin around Monday evening, becoming more widespread overnight into Tuesday morning. Areas of San Diego County have the best chance to see rainfall. The showers will be scattered in nature, with some areas seeing over a quarter of an inch and others minimal totals to none. The core of low pressure system moves to the east later on Tuesday, where residual showers may linger across the mountains into the afternoon with partial clearing closer to the coast.
This system will also bring much cooler weather. Monday and Tuesday will be the coolest days of the upcoming week with highs only reaching the 40s to near 50 degrees in the mountains and highs in the 60s for areas west of the mountains into the high desert. Comfortable 70s will take hold across the Anza Borrego desert into the Palm Springs area.
040000z. Coast/Valleys, Mid level clouds based ~4500ft MSL currently SCT-BKN across the coastal basin this afternoon will become more BKN-OVC into this evening. An initial wave of widely scattered VCSH becomes possible starting after 06z Monday, ending by 15-18z. This VCSH will likely be accompanied by a lower layer of clouds near 2000-3000ft, which may bring brief CIGs overnight (20- 40% chance). Lower level clouds departing with the VCSH by 18z, with the mid level clouds (~4500ft MSL) becoming more SCT-BKN again.
.Mountains/Deserts, Strong winds have picked up this afternoon with widespread gusts into the deserts of 25-35 kts, locally up to 45-50 kts along desert mountain slopes and through mountain passes. Winds gradually weakening between 06-12z, remaining elevated through passes before picking back up after 21z Monday with similar strength gusts to today.
Additionally, coastal mountain slopes locally obscured between 4000- 6000 ft MSL in BR with clouds intersecting terrain. These clouds will increase in coverage after 03z Monday, become less numerous by 18z.
No hazardous marine conditions are expected through Thursday.
Ca, None. PZ, None.
