Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
100 FXUS66 KSGX 200342 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 845 PM PDT Wed Jun 19 2024 .SYNOPSIS... A building ridge over the Desert Southwest will bring hotter weather this weekend through the middle of next week when highs will be 8 to 12 degrees above average in the valleys, mountains and deserts. A shallow marine layer will limit the heating in the coastal areas, but temperatures there will also be a few degrees warmer than average. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Highs today were similar to yesterday, but highs tomorrow will be a little warmer in the valleys, mountains and deserts as heights increase over the Southwest. Even greater warming occurs Friday when the ridge of high pressure over the Texas propagates westward and then settles over the Four Corners this weekend. There it will stay through most of next week, bringing the second heat wave of the season with highs in the lower desert from 110-115. Heat products will likely be needed in the deserts and perhaps the Inland Empire. The coastal zones will be warmer too, but the heat will be modified by the shallow marine layer that will keep highs from 70-80 within a few miles of the coast, and from 85-95 in the San Diego Valleys and inland Orange County. A weak monsoon surge Saturday through Monday will bring mid and high clouds aloft and increasing humidity at the surface. This westward surge of deeper moisture will remain over Arizona where monsoon thunderstorms are likely, while the chances of convection over the SoCal mountains and deserts are small. && .AVIATION... 200300Z...Coast/Valleys...Areas of low clouds will continue to develop along the coast through 05Z then spread mostly to around 25 miles inland by 12Z Thu, with patchy stratus spreading into far west and south parts of the Inland Empire. There is a 60% chance that KONT will have a BKN CIG albeit briefly in the 12Z-15Z Thu period. Most CIGs will be 900-1600 ft MSL with tops to 1800 ft MSL with a lowering trend overnight, with local VIS below 3 miles in BR/FG in the valleys, including VCNTY KRNM. Most valleys will clear 14Z-16Z Thu, with coastal areas clearing 16Z-19Z Thu. Areas of low clouds will develop again Thu evening. Mountains/Deserts...Mostly clear with unrestricted VIS will continue through Thu evening. Local gusts from the west will be 20-30 kt through San Gorgonio Pass and the desert slopes. && .MARINE... No hazardous marine weather conditions are expected through Monday. && .FIRE WEATHER... Fuels have dried out inland to average levels but winds are trending lighter into the weekend to normal diurnal wind. Areas along and east of I-15, mountains and deserts, have been notably warmer than normal compared the coastal areas that have been running below average past 60 days. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...Moede FIRE WEATHER...Tardy AVIATION/MARINE...Maxwell