Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
187 FXUS66 KSGX 281629 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 929 AM PDT Sun Apr 28 2024 .SYNOPSIS... Warm and dry conditions continue through much of this week. Marine layer low clouds and fog will likely be confined to the coast and the western coastal valleys during this time. The mountains and deserts will also experience breezy winds from the west each afternoon and evening. There is a chance for some weak Santa Ana winds on Thursday, followed by another round of cooler and breezier weather by next weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... 9 AM Update: Low clouds have cleared the coast of Southern California, setting the stage for a pleasant day with seasonal temperatures. Winds from the west are still expected to pick up over the mountains and deserts later this afternoon and evening, though winds today are expected to be weaker than yesterdays with peak gusts generally in the 25-40 mph range. The forecast generally looks on track and no major changes are planned this afternoon. Previous Discussion Issued at 155 AM PDT: A weak coastal eddy is helping low clouds sneak near the coast this morning. Latest WRF/HRRR guidance show this regime occurring over the next few days, through Tuesday, which will prompt low clouds and patchy fog within 10 miles of the coast. Today will be noticeably warmer, especially away from the immediate coast with highs near 80 across the Inland Empire and low 90s across the Coachella Valley and Anza Borrego Desert. Warming will continue by Monday and Tuesday as weak high pressure prevails over the region, with many areas along and west of the mountains getting into the mid/upper 60s at the beaches and higher elevations to lower 80s across the Inland Empire and High Desert. NBM indicates breezy west winds each afternoon/evening across the mountains and deserts with gusts near 20-30 MPH. A passing trough across the Pacific Northwest will tighten the pressure gradient over our region, leading to increased onshore flow and a deeper marine layer. Temperatures will remain close to slightly above average. Ensemble clusters are still in disagreement on the position of where this trough goes, but depending how far south it goes across the Great Basin, it will generate Santa Ana winds. For now, the winds look weak with low probabilities of winds greater than 30 MPH per latest NBM guidance. Another trough may form over the western U.S., leading to more cooler and breezier weather by later next week with continued dry weather. && .AVIATION... 281622Z...Coast/Valleys...BKN clouds with ceilings 1,500 feet AGL are rapidly dissipating, last around KSAN. Expect similar clouds and ceiling developing late tonight between 06 to 09 UTC mainly for CRQ to SAN. Mountains/Deserts...Clear through today. Northwest winds 10 to 15 kt in deserts after 00 UTC and locally in mountains after 18 UTC. && .MARINE... No hazardous marine conditions are expected through 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...Adams AVIATION/MARINE...Tardy