006 FXUS66 KSGX 020359 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 859 PM PDT Sun Jun 1 2025 .SYNOPSIS... Virga and light showers continue through tonight. Cooler weather with highs near normal will occur through much of the week. There is a 10-20 percent chance of showers and thunderstorms Tuesday afternoon into Wednesday morning across the mountains and deserts as an area low pressure enters the region. Dry with minor warming for the latter half of the week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Evening update... Thick mid and high cloud coverage today prevented any surface- based convection from developing over our forecast area aside from one brief heavier shower near Campo in San Diego County. The center of the upper level low is currently moving into the lower Colorado River Valley with some virga or light showers wrapping around the back side into our mountains and deserts. This activity will come to an end later tonight as the low continues to move eastward. Otherwise patchy low clouds for the coastal areas and muggy conditions overnight, especially in the low deserts. Previous discussion... Another weak area of low pressure will move down the coast on Monday. PWAT values lower as our system from today departs, but humidity will stick around. High temperatures will be similar in most places on Monday, but a few degrees cooler closer to the coast and valleys. The low pressure system moves inland over our region by Tuesday, which will pull in subtropical moisture and increased instability once again with ensemble models showing CAPE near 500-700 J/kg. NBM precipitation chances near 15-25% across the mountains and deserts remain sufficient for this forecast. Forecast timing on this is moderate with latest thinking as notable chances from Tuesday morning through Tuesday night. The weak weather system will depart late Tuesday, as a troughing pattern over area remains from Wednesday through later in the week. This pattern will keep us dry with highs near seasonal averages. Models depict our region between two large areas of high pressure, one over the Pacific and the other over Mexico. Ensemble model guidance is leaning toward the area of high pressure over Mexico expanding closer to our region, which will bring slightly warmer weather by next weekend. && .AVIATION... 020400Z...Coasts/Valleys...SCT-BKN mid level clouds at 6,000- 13,000ft MSL continue to stream overhead but will gradually decrease in coverage by Monday morning. Meanwhile, patchy low clouds based 1,000-1,500ft MSL are slowly increasing in coverage off the coasts. These will continue to build and push ashore in the next several hours, bringing CIGs to the coastal TAF sites by 07-09z. These clouds will move about 15 mile inland by 12z MOnday, with VIS obscurations where clouds intersect higher terrain, with better visibility for the immediate coast. Clouds clear by 16-17z Monday morning but may linger offshore into the afternoon. Marine layer clouds look to surge back inland fairly early Monday evening, as early as 00-03z Tuesday. Deserts/Mountains...SCT-BKN mid level clouds near 10,000ft will gradually clear out by Monday morning, giving way to mostly clear skies through Monday night. && .MARINE... No additional hazardous marine conditions are expected through Thursday. && .BEACHES... A long period south swell builds into the region today, leading to elevated surf for south and southwest facing beaches of 4 to 6 feet with sets to 7 or 8 feet possible. This will result in higher rip current risk and locally hazardous swimming conditions. Surf peaks Monday and gradually diminishes Tuesday through Wednesday. A Beach Hazard Statement is in effect and contains more information. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement through Tuesday afternoon for Orange County Coastal Areas-San Diego County Coastal Areas. PZ...None. && $$ PUBLIC...SS/APR AVIATION/MARINE/BEACHES...Munyan