Weak high pressure over the region will bring warmer weather with highs up to 10 degrees above normal. The marine layer will continue to bring low clouds each night and morning across parts of the coastal basin for the foreseeable future. An area of low pressure will move near the area Sunday through Tuesday. This will bring cooler and breezier weather by Sunday, with the chance of light rain showers by Monday and Tuesday. Drier weather with a warming trend is expected for the latter half of next week.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
Satellite imagery at 9 PM was showing areas of low clouds along the coast and reaching into portions of the western valleys. Warm conditions expected Saturday with highs 5 to 10 degrees above average for inland locations. Forecast is still on track for early next week with cooler conditions, increased winds, and rain chances. Highest chances of rain are Monday night into Tuesday morning. Nbm chances for 48 hour rainfall totals from Monday morning through Wednesday morning exceeding 0.10" are 40 to 60 percent in the mountains and 20 to 40 percent for the coast and valleys. Chances of the coastal slopes exceeding 0.25" over that same 48 hour period is 20 to 30 percent. Dry conditions will return for most of Wednesday.
From previous discussion issued at 2 PM Saturday May 1, 2026,
Low clouds will continue to clear most areas, though some will linger near the beaches through the afternoon as a deep marine layer is in place. High temperatures will be warmer than yesterday as the area of low pressure impacting the region has moved to the east and a weak area of high pressure has made its way over our area. Highs will reach into the 70s/80s this afternoon for inland valleys and the high desert. Temperatures will not change too much into tomorrow as the high slowly slides eastward.
A closed low will move near California by Sunday. This will bring cooling to inland areas up to 10 degrees along with windier conditions across the mountains and deserts. Confidence is moderate to high in seeing wind gusts 35 mph or more Sunday afternoon and evening across the desert slopes into the deserts. As the low draws closer, PWAT values increase slightly but the system does not look to have much moisture. Areas of San Diego County have the best chance to see rainfall, especially along the coastal slopes. Whatever falls will be light. The coolest temperatures of the week will occur as this system passes through the region on Monday and Tuesday with highs 5 to 15 degrees below normal. Big Bear has around a 25-40% chance of reaching 50 degrees, Julian a 60-70% each day. Highs in the 60s will prevail for areas west of the mountains with 70s to near 80 degrees across the lower deserts.
Ensemble models are in fair agreement of this low moving out of the region by Wednesday, where a ridge will take its place. This will bring drier and warmer weather to the region. Inland valleys are expected to warm about 7-12 degrees from Tuesday to Wednesday. This may occur again by next Thursday as the area of high pressure expands later into the week.
020430z. Coast/Valleys, Low clouds based 1400-2000 ft MSL have filled into coastal San Diego County and parts of coastal Orange County. Clouds will continue their March into San Diego/Orange Counties, reaching up to 20 miles inland by 09-11z. There is about a 70-80% chance for IFR cigs to reach into the southern and western Inland Empire including KONT after 10z (40-50% chance at KSBD). Minor vis reductions (4-6SM) in the Inland Empire where clouds develop. Clouds clear to the coastline by 18-19z Sat, but may linger just offshore through the afternoon. Low clouds return to land areas in similar fashion Saturday evening with similar to slightly higher bases.
.Mountains/Deserts, VFR conditions expected through the period with SCT-BKN high clouds AOA 20 kft after 18z Sat.
No hazardous marine conditions are expected through Wednesday.
Ca, None. PZ, None.
