Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
101 FXUS66 KSGX 020938 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 238 AM PDT Thu May 2 2024 .SYNOPSIS... Into Saturday, night and morning coastal low clouds will spread inland into the valleys with high temperatures near average at the coast to around 5 degrees above average inland. A fast-moving low pressure system moving inland across California Saturday night will bring cooling for Saturday and Sunday with Sunday high temperatures as much as 15 to 20 degrees below average for the mountains. There will be stronger and gusty southwest to west winds for the mountains and deserts for late Saturday into Sunday with the strongest gusts to 55 to 65 mph. There is also a slight chance of light showers from the coast to the mountains for late Saturday night into early Sunday. Dry and warmer for Monday through Wednesday, but with high temperatures remaining a few to around 5 degrees below average. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Saturday)... There is once again a coastal eddy early this morning with extensive low clouds over the Baja coastal waters spreading northward along the southern California coast. The low clouds cover much of the Orange County coastal plain and extend inland in San Diego across portions of the valleys. The low clouds are expected to spread farther inland across much of the valleys for tonight into Friday morning and again for Friday night into Saturday morning. Generally minor day-to-day changes in high temperatures are expected for today and Friday with high temperatures near average at the coast to around 5 degrees above average for inland areas. Onshore flow will begin strengthening on Saturday spreading cooling inland with coastal high temperatures on Saturday a few degrees cooler to around 5 degrees cooler for the mountains, inland valleys, and high desert. && .LONG TERM (Saturday night through Wednesday)... A low pressure system from the northwest will move quickly inland through California Saturday night and through the Great Basin Sunday. It will bring much stronger onshore flow for late Saturday through Sunday. There will be stronger and gusty southwest to west winds for the mountains and deserts with the winds strengthening Saturday afternoon and evening, peaking around daybreak Sunday, then subsiding Sunday night. Strongest gusts for Saturday night into Sunday morning along the desert slopes of the mountains and adjacent desert areas of 55 to 65 mph are expected. There is also a slight chance for light showers for late Saturday night into Sunday morning with any rainfall of less than one-tenth inch near the coast to one-tenth to locally one-quarter inch for the coastal mountain slopes. High temperatures on Sunday will be much cooler, as much as 10 to 15 degrees cooler for the mountains and deserts with high temperatures in the mountains as much as 15 to 20 degrees below average, mostly in the mid 40s to lower 50s. Monday will be dry and much warmer, around 5 degrees warmer at lower elevations to 8 to 12 degrees warmer for the mountains with not much change for Tuesday and Wednesday, generally a few to around 5 degrees below average. && .AVIATION... 020920Z...Coasts/Valleys...Low clouds with bases 1400-1800 FT MSL will continue to fill in across the coastal basin this morning. Cigs possible vcty KONT/KSBD 11z-16z Thu. Areas of reduced vis of 2-4 SM through 16z Thu in the valleys. Scatter out 15-17z Thu across the valleys, and 17z-19z Thu near the coast, though some beach locations could see BKN this afternoon. Low clouds spreading back inland after 00z Fri with bases 2000-2500 FT MSL. Otherwise, clear skies with unrestricted vis through tonight. && .MARINE... No hazardous marine conditions are expected through Saturday morning. Gusty west to northwest winds late Saturday through Sunday are likely to generate hazardous boating conditions, especially in the outer waters. Current estimates for peak gusts is 25-30 knots, with the probability of gale force winds less than 20 percent. && .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...17 AVIATION/MARINE...EA