Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
580 FXUS66 KSGX 100427 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 927 PM PDT Sun Jun 9 2024 .SYNOPSIS... Night and morning low clouds will continue west of the mountains this week. Warmer for Monday and Tuesday, followed by slight cooling through the rest of the work week. Warmer by next weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Evening Update... After some better clearing this afternoon, low clouds have redeveloped along the coast and have begun to spread inland. The 00Z KNKX sounding shows the marine inversion based near 2600 ft MSL, down around 400 ft from this morning. An upper level low off the coast and a weak eddy tonight will help keep the marine layer propped up. Hi-res guidance isn`t showing as much precipitation as last night, but patchy drizzle with mostly trace amounts still isn`t out of the question for tonight into Monday morning. Onshore pressure gradients have weakened from yesterday afternoon, and as a result onshore winds through the passes aren`t quite as strong, peaking at around 40 mph as of 9 PM. These winds will slowly diminish overnight. Previous discussion... A closed low developing in the base of the trough will break off from the mean flow and strengthen before parking off the coast of northern Baja California through much of the upcoming week. This will help to maintain a stout marine layer, with night and morning low clouds west of the mountains each day. High level moisture will result in passing high clouds through at least Tuesday. Slow warming develops tomorrow and Tuesday as a ridge builds to the north and east of our region. Tuesday looks to be the warmest day of the week, with highs 5-10 degrees above normal in the deserts, resulting in moderate heat risk. West of the mountains will continue to be moderated by the persistent marine layer. The upper low becomes absorbed into the mean flow late this week, resulting in a few degrees of cooling and increasing onshore winds. Warmer by next weekend. && .AVIATION... 090345Z...Coast/Valleys... Low clouds will quickly spread inland again tonight with bases around 1500-2000 feet above MSL and will again reach most valleys by 09Z Mon. Slightly earlier clearing for Monday, generally 15-17z for inland valleys and 17-19z for the coasts. Mountains/Deserts...FEW-SCT250 and unrestricted VIS through Mon morning. Areas of W-NW winds with gusts 25-35 kt will occur again through 08Z Mon from the mountain crests east through the desert slopes and into the adjacent deserts. && .MARINE... No hazardous marine conditions are expected through Thursday. && .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...SS/EA AVIATION/MARINE...Suk