Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
912 FXUS66 KSGX 110413 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 913 PM PDT Mon Jun 10 2024 .SYNOPSIS... Night and morning low clouds will continue west of the mountains this week. Warmer across inland areas through Wednesday, with slight cooling following on Thursday. Warmer this weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Evening update... Orange County manages to remain mostly clear this evening, but low clouds have pushed into the valleys in San Diego after a day of actually clearing at the coast. The 00Z KNKX sounding shows a marine inversion based near 2100 ft MSL, down around 500 ft from this morning. Low clouds will not extend as far inland tonight with the shallower marine layer in place. No big changes to the forecast this evening with June remaining gloomy. Previous discussion... Inland areas will warm an additional 2-5 degrees tomorrow, with highs generally around 3-5 degrees below normal for the coasts and valleys and 5 to 10 degrees above normal in the mountains and deserts. Little change is expected for Wednesday. The marine layer will become more shallow as height rises from the building ridge to the east impede upon Southern California. Low clouds won`t extend quite as far inland tonight into tomorrow morning, with this more shallow trend continuing into Thursday. The valleys should clear by late morning or early afternoon each day, with less certainty on if/when the coast clears out. The persistent marine layer will also continue to keep the coast seasonably cool. The 12z ensemble guidance suite has come into closer alignment on the evolution of the upper low that is currently located to our southwest: models show the low meandering off the coast of northern Baja or Southern California through Wednesday before becoming an open wave and moving inland Thursday into Friday. This will lead to gusty winds over the mountains and desert slopes, and slight cooling region-wide. After the low passes, a high pressure system will promote warming again on Friday and Saturday. && .AVIATION... 110335Z...Coast/Valleys...BKN-OVC cigs will continue to spread inland this evening and only reach the far west and south parts of the Inland Empire by 12Z Tue. Local vis restrictions of 2-4 SM in BR/HZ near higher coastal terrain and in the valleys on the edge of the cloud deck. Bases will be slightly lower tonight, around 700- 1200 ft MSL. There is a 40% chance of cigs with bases below 1000 ft at KONT and an 80% chance at coastal TAF sites from 11-16Z Tue morning. Low clouds should clear inland areas 16-18Z Tue and SCT out at the coast 18-20Z Tue. Moderate confidence in cigs lingering at the immediate coast into Tuesday afternoon. Mountains/Deserts...Occasional SCT clouds AOA 25000 ft and unrestricted VIS through Tue. && .MARINE... No hazardous marine 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...SS/EA AVIATION/MARINE...Suk