Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
116 FXUS66 KSGX 180925 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 225 AM PDT Sat May 18 2024 .SYNOPSIS... A troughing pattern will persist through the weekend into much of next week. This will bring a deeper marine layer west of the mountains with mostly cloudy conditions, especially closer to the coast. A weak area of low pressure will bring some cooler weather by Monday with gusty west winds across the mountains and deserts. Slight warming comes back into the picture for inland areas by Tuesday into the end of the week with slight variations in temperatures expected. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... An area of high clouds continues to progress across the region with low clouds filling into most areas west of the mountains this morning. Patchy fog and drizzle may once again occur from the coast to the western foothills. Latest HREF guidance shows lower (20-40%) chance of mostly cloudy skies near the beaches by Saturday afternoon, so we may see some better clearing than yesterday. About the same cloud cover can be expected for Sunday. This troughing pattern will keep the winds elevated across mountains and deserts through early next week, where west and southwest wind gusts 20-35 MPH will be common. A weak area of low pressure will move into the area, helping deepen the West Coast trough a bit further by Monday. This will increase winds slightly and cool much of Southern California. Probabilities are moderate to locally high in seeing wind gusts over 40 MPH during this time across mountain passes into the deserts. Daytime highs will be near 5 degrees below average along the coast to up to 10 degrees below average inland. Highs will range from near 60 degrees at the coast and mountains to near 90 in the lower deserts. The troughing pattern will continue into much of next week. After the low passes through, heights will lift by Tuesday, weakening winds and boosting temperatures up some, though still slightly below average. May gray looks to continue for coastal and western valley regions with sunnier weather across inland areas by next week. && .AVIATION... 180850Z...Coast/Valleys...BKN/OVC low clouds with bases 1500-2500 ft MSL and tops to 3000-3500 ft MSL with areas of terrain obscurations continuing across the coastal basin this morning. Below the cloud deck vis will mostly be unrestricted. Clearing will be slow, between 17Z-20Z in the valleys with partial clearing between 20Z-00Z near the coast. Stratus will rapidly spread inland again after 00Z, spreading into the inland valleys again overnight. Little change in bases/tops on Sunday. Mountains/Deserts...SCT high clouds AOA 20,000 ft MSL through 18Z. Otherwise, clear skies with unrestricted VIS will prevail through Sun morning. W-SW winds with gusts 25-35 kt will continue through 12Z mainly on the desert mountain slopes and through/east of passes/canyons. W-SW winds strengthen again this afternoon with gusts 30-45 kt through tonight. MOD UDDFS and LLWS will occur at times over/E of the mtns. && .MARINE... No hazardous marine conditions are expected through Wednesday. && .BEACHES... A series of southwest swells of 2-3 ft at 16-18 seconds from 210-220 degrees will build through Sunday and continue through Tuesday, producing above normal surf of 3-5 ft with locally higher sets on exposed SW facing beaches, as well as a high risk of rip currents at all beaches. Swell and surf will slowly lower beginning Wednesday. && .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...APR AVIATION/MARINE...SS