Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
580 FXUS66 KSGX 182052 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 152 PM PDT Sat May 18 2024 .SYNOPSIS... A troughing pattern over the eastern Pacific will persist through the weekend and 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 closed upper low will bring some cooler weather by Monday with gusty west winds across the mountains and deserts. Slight warming returns for inland areas by Tuesday into the end of the week with slight day-to-day variations in temperatures. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This afternoon, mostly clear and breezy. Sfc pressure gradients are onshore with 4.2 mb SAN-DAG and 6.2 mb SAN-IPL. Wind gusts of up to 51 mph have been reported in the windiest locations, otherwise wind gusts are mostly less than 30 mph. The marine layer remains deep and low clouds are likely to move ashore again in a few hours. From previous discussion... A dominant, large-scale troughing pattern will persist through much of the coming week. As a result, gusty west to southwest winds will continue across mountains and deserts through early next week. Wind gusts of 20-35 MPH will be common. A weak upper low will move into the region on Monday, becoming an open wave in the process. This will bring some cooling, a deepening of the marine layer and stronger westerly winds. Gusts of 40-50 mph will likely occur in wind-prone locations. Monday will likely be the coolest day, with daytime high temps about 5 degrees below normal in the coastal areas and the deserts. Inland Valley temps could be as much as 12 degrees below normal. Highs temps will range from near 60 degrees at the coast and mountains to near 90 in the lower deserts. The troughing pattern will through much of next week. After the low passes through, heights will rise by Tuesday, weakening winds and increasing temperatures somewhat, though still slightly below average. Typical May weather will continue through next week, with minor day-to- day variations in temperatures and marine layer cloud cover west of the mountains. && .AVIATION... 182030Z...Coast/Valleys... Clearing conditions will continue across the coastal regions with most inland valleys already SKC. Stratus will rapidly spread inland again after 00Z, spreading into the inland valleys again overnight. Expect 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. Below the cloud deck vis will mostly be unrestricted. Clearing Sunday will be slow, between 17Z-20Z in the valleys with partial clearing between 20Z-00Z near the coast. Mountains/Deserts... Clear skies with unrestricted VIS will prevail through Sun morning. 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...PG AVIATION/MARINE/BEACHES...Suk