Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
381 FXUS66 KSGX 181628 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 928 AM PDT Tue Jun 18 2024 .SYNOPSIS... Warmer conditions are expected today, with not much change for Wednesday and Thursday, followed by a few degrees of warming into the weekend. Above average high temperatures are expected to prevail for much of the area Friday into the early and middle part of next week, especially for the deserts. The marine layer will gradually get shallower for the end of this week into early next week remaining mostly confined to the coast into portions of the valleys at times. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Visible satellite imagery at 9 AM is showing areas of low clouds clearing from the Inland Empire. High temperatures today are expected to be a few degrees warmer than yesterday along the coast and in the deserts. For the inland valleys and coastal mountain slopes, highs are expected to be 7 to 15 degrees warmer than yesterday. Not much change in high temperatures is expected for Wednesday and Thursday, with additional warming Friday into the weekend. Through Friday, the marine layer will stay 2000 to 2500 feet deep with night and morning coastal low clouds extending into portions of the inland valleys for late each night. The marine layer will get shallower for the weekend into early next week. An area of high pressure aloft building over the desert southwest will expand west into Southern California Friday into Saturday bringing additional warming. The high pressure system will remain parked over the Southwestern United States for much of next week, maintains above average temperatures for most areas. will increase for inland areas west of the mountains as the marine layer gets shallower under the high pressure regime. For Friday through Monday, the current forecast has the highest for the Inland Empire on Saturday and for the San Diego County deserts on Sunday. The coast and valleys may cool slightly early next week with not much change or slight warming for the deserts. The deterministic NBM has a forecast high temperature for Palm Springs of 112 on Friday with high temperatures between 112 and 115 through at least Friday of next week. The probabilities for a high temperature of 110 or higher at Palm Springs are lowest for Tuesday and Wednesday of next week at 47 percent. One limiting factor of the high temperature forecast is the ridge looks to bring an increase of midlevel moisture to the deserts, with the potential for precipitable water values to reach near an inch. That increase in moisture would help taper high temperatures but guidance continues to support at least a full week of excessive or near excessive heat for the lower deserts. && .AVIATION... 181620Z...Coast/Valleys...Low clouds with bases 1600-2000 ft MSL are clearing out of the inland valleys this morning. These will be tops to 3000 ft MSL. Clouds scattering at the coast by 17-19Z, though BKN cigs may linger near the beaches. Low clouds with bases 1200-1600 ft MSL redeveloping along the coast around 03Z Wednesday and spreading 15-20 mi inland overnight, mainly impacting San Diego and Orange Counties. Mountains/Deserts...Mostly clear with unrestricted vis. West winds with gusts near 25 kts below the San Gorgonio Pass this afternoon and evening. Otherwise, quiet weather expected through tonight. && .MARINE... No hazardous marine weather conditions are expected through Saturday. && .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...CO AVIATION/MARINE...APR