Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
958 FXUS66 KSGX 310400 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 900 PM PDT Thu May 30 2024 .SYNOPSIS... Warm weather will continue for inland areas into Friday as high pressure over Mexico expands further north. A trough to the north will move through the region this weekend bringing slightly cooler conditions, greater marine layer cloud coverage west of the mountains, and gusty west winds for mountains and deserts. A strengthening ridge will build across the West into next week, leading to another slow warming trend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Evening update... Low clouds have begun to spread back into the coastal areas this evening. Elsewhere skies were clear with locally breezy conditions through the mountain passes. The 00Z KNKX sounding shows the marine inversion base near 2100 ft MSL, up slightly from this morning. Low clouds will spread into the inland valleys once again tonight, clearing to the coast by by the early afternoon. Little change in high temperatures on Friday with highs near to slightly below normal for the mountains westward and around 5-7 degrees above normal in the deserts, meaning around 100-105 degrees in the low deserts. Previous discussion... Ensemble model guidance confirms a weak trough pushing into the Pacific Northwest by Saturday, providing some subtle influence on our weather for the weekend. This will bring cooling inland, lowering temperatures up to 5 degrees or so from what we are seeing today per latest NBM guidance. Sunday will be the coolest day overall with highs in the 70s and 80s for western valleys, mountains, into the high desert. The marine layer will become slightly deeper, where clouds will fill in most of the coastal basin each evening into the morning hours. West winds will be gusty each afternoon and evening this weekend as well, generally 25-40 MPH. Agreement is fairly in line with a ridge building over the West Coast by Monday, pushing inland toward the Great Basin through the week. This will bring gradual warming to our region each day into at least the middle of next week with a shallower marine layer and less wind for mountains and deserts. && .AVIATION... 310330Z...Coast/Valleys...Low clouds beginning to spread inland at this hour. Bases are around 1500 ft MSL with tops to about 2000 ft MSL. CIG impacts currently at KSAN and KCRQ, likely at KSNA by 06Z. Low clouds could spread up to 25 miles inland, with a 45-60 percent chance for CIGs at KONT 10Z-15Z but less than a 40 percent chance for CIGs at KSBD. Cloud bases will likely lower by a few hundred feet 06Z-15Z with higher terrain obscured and VIS restrictions inland where clouds and terrain intersect. Expect inland clearing 16Z-18Z and clearing to the coast 18z-20z. Mountains/Deserts...Clear skies with unrestricted VIS through Fri. && .MARINE... No hazardous marine conditions are expected through Tuesday. && .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/APR AVIATION/MARINE...PG