Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
446 FXUS66 KSGX 010418 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 918 PM PDT Mon Jun 30 2025 .SYNOPSIS... A few degrees of cooling is expected for all areas Tuesday, with additional minor cooling each day through Thursday. A gradual warming is expected Friday through the weekend. Night and morning low clouds and fog are expected to remain persistent along the coast and into the western valleys through the week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This evening, the marine layer remains at a consistent depth and low clouds are developing along the coast of San Diego County. The clouds and some patchy fog will spread inland and northward into Orange County and could reach up to 15 miles inland by sunrise. From previous discussion... An upper level low off the coast of California nearly due west of Pt. Conception will propagate southeast tomorrow through Thursday. It will pull some mid to upper level moisture from the tropics into Southern California mainly Tuesday and Wednesday. This will result in areas of high cloud coverage across the area and the development of cumulus clouds over the mountains. There is a 10 percent or less chance that any showers or thunderstorms develop. Only a few members of both the ECMWF and GFS ensembles show light precipiation in the mountains. High resolution models are showing an isolated light rain shower or two in the San Bernardino Mountains and northeast into portions of the High Desert Tuesday and Wednesday. Confidence is not currently high enough to officially introduce a slight chance of showers into the forecast. For the 4th of July holiday through the weekend, temperatures will remain within a few degrees of average with dry conditions prevailing. Marine layer low cloud and fog coverage will remain persistent each night and morning into early next week with minor variations in depth and coverage. && .AVIATION... 010345Z....Coast/Valleys...Stratus with bases 1000-1500 ft MSL filling in along the coast through 07Z, then spreading 10-15 mi inland by 11Z. Local vis 3-5 SM where stratus nears terrain in the valleys. Clouds and vis restrictions clearing inland 14-16Z and along the coast 16-18Z, though there is a 50-60% chance of BKN-OVC CIGS at the San Diego County beaches through the afternoon. Clouds spreading back into the coastal areas after 02/03Z with similar bases. Otherwise areas of FU/HZ near ongoing wildfires in the Inland Empire. .Mountains/Deserts...West winds gusting 25-35 kt through the passes and on the desert mountain slopes Tuesday afternoon and evening with associated MOD UDDFS over and east of the mountains. && .MARINE... No hazardous marine weather conditions are expected through Saturday. && .BEACHES... Building southerly swell (190 degrees) of 3 feet at 14-15 seconds will generate elevated surf of 3-5 ft with sets to 6 ft along southerly facing beaches and strong rip and longshore currents at all beaches Friday and Saturday. Swell and surf will begin to lower on Sunday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...PG AVIATION/MARINE/BEACHES...SS