Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
849 FXUS66 KSGX 290418 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 918 PM PDT Tue May 28 2024 .SYNOPSIS... Fairly seasonal conditions will continue into Wednesday, with a slight warm up by Thursday and Friday for areas away from the coast due to weak high pressure. With this warming, the marine layer will shrink with some faster clearing each morning for valleys with better chances for clearing at the beaches. Weak troughing looks to come back into the picture by the weekend, which will cool inland areas a few degrees along with a bit more low cloud coverage nights/mornings west of the mountains. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Update... The 00z Miramar sounding showed a 5.5C degree inversion based near 1400 feet. The marine layer is slightly more shallow than yesterday so clouds likely won`t extend as far inland tomorrow morning. At 9 PM, low clouds extend across the coast and western valleys, and breezy conditions are occurring along the coastal slopes. High temperatures tomorrow will be within 1-2 degrees of today, with highs topping out 1-5 degrees below normal across the coast through the coastal mountain slopes, and 1-4 degrees above average along the desert slopes into the deserts. Previous Discussion (Issued 125 PM PDT Tue May 28 2024)... High pressure across northern Mexico will shift further north by Thursday and Friday. This will shrink the marine layer even more with slightly warmer temperatures inland. NBM probability points to about a 30-40% chance in high temperatures over 105 degrees by this time in the springs of Borrego and Palm. This will lead to areas of moderate heat risk, so impacts will be felt to those sensitive to heat or without proper cooling/hydration. Heights will lower once again by the weekend with a few degrees of cooling for inland locales, where the region will be near average with breezy conditions for desert mountain slopes into adjacent desert regions. With this will also come a slightly deeper marine layer, with more low cloud coverage and patchy valley fog for areas like the Inland Empire each night and morning. && .AVIATION... 290410Z...Coast/Valleys...OVC007-015 moving into the inland valleys through 14Z Wednesday followed by slow clearing back to the coast through 20Z. CIGS will only briefly clear at KSAN, KCRQ and KSNA between 20-24Z. Mountains/Deserts...Gusty west winds 30-40 knots on desert mountain slopes and locally into the deserts Wednesday afternoon and evening. && .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...EA/APR AVIATION/MARINE...Moede