Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
338 FXUS66 KSGX 181102 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 402 AM PDT Tue Jun 18 2024 .SYNOPSIS... Today it will be warmer inland with not much change for Wednesday and Thursday. High pressure to the south will bring warming for Friday through the weekend. For the early and middle part of next week, not much change with high temperatures for the deserts around 5 to 10 degrees above average and a few to around 5 degrees above average for the coast and valleys. The marine layer will continue to keep coastal areas cooler with night and morning coastal low clouds spreading into portions of the inland valleys late each night. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Thursday)... Onshore flow will weaken today with much drier air for inland areas. It will be warmer today with high temperatures for the inland valleys and mountains below 5000 feet as much as 10 to 15 degrees warmer than Monday. Not much change in high temperatures for Wednesday and Thursday. The marine layer will remain near 2000 to 2500 feet deep with night and morning coastal low clouds extending into portions of the inland valleys for late each night. && .LONG TERM (Friday through Monday)... High pressure to the south is expected to bring warming for Friday and Saturday with not much change for Sunday. The Heat Risk for inland areas will be increasing with the rising temperatures. For Friday through Monday, the current forecast has the highest Heat Risk 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. Guidance continues to support a period of a week or longer of excessive or near excessive heat for the lower deserts. && .AVIATION... 180830Z...Coast/Valleys...Low clouds with bases 1500-2000 ft MSL and tops to 2500 ft will continue to spread into portions of the valleys through 14Z. Local vis 3-5 SM in BR/HZ where clouds near terrain in the valleys. Clouds clearing inland 15-17Z and near the coast 17- 19Z. Low clouds with bases 1000-1500 ft MSL redeveloping along the coast around 19/03Z and spreading 15-20 mi inland overnight. Mountains/Deserts...Mostly clear with unrestricted vis through Wed morning. West winds with gusts 25-40 kt are expected with isolated gusts 45 kt below the San Gorgonio Pass weakening through 12Z. up/downdrafts over and east of the mountains through the early morning. && .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...17 AVIATION/MARINE...SS