313 FXUS66 KSGX 070941 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 241 AM PDT Mon Jul 7 2025 .SYNOPSIS... High pressure aloft will strengthen across southern California through the middle of this week with the heat peaking on Wednesday and Thursday with high temperatures for inland areas 5 to 10 degrees above average. Not as hot for next weekend into early next week with high temperatures for next Sunday and Monday near to around 5 degrees below average for the coast and valleys and around 5 degrees above average for the deserts. Night and morning coastal low clouds will spread into the western valleys for early this week and again for next weekend. The marine layer will be shallower for Wednesday through Friday with the coastal low clouds only spreading into the far western valleys. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (Today through Wednesday)... Upper level low pressure will remain centered off the coast of northern and central northern California through Tuesday before weakening and move inland through northern California on Tuesday night and Wednesday. High pressure aloft over the interior southwest states will strengthen and expand across southern California for Wednesday and Thursday. High temperatures will warm for Tuesday and Wednesday with not much change for Thursday. Wednesday high temperatures will be as much as 5 to 10 degrees above average for inland areas with high temperatures on Wednesday ranging from the 70s near the coast to the mid 90s to 102 for the Inland Empire with 114 to 118 for the lower deserts. A marine layer around 2000 feet deep will decrease to around 1500 feet on Wednesday. Night and morning coastal low clouds will continue to extend inland into the western valleys into Tuesday morning, then only into the far western valleys for late Tuesday night into Wednesday morning. && .LONG TERM (Thursday through Sunday)... Not much change in high temperatures for Thursday followed by cooling for next weekend into early next week as high pressure aloft slowly weakens. For next Sunday and Monday, high temperatures for the coast and valleys will be near to around 5 degrees below average with the deserts around 5 degrees above average. High temperatures for next Sunday will range from the lower to mid 70s near the coast to the upper 80s to upper 90s for the Inland Empire with 110 to 114 for the lower deserts. The marine layer will deepen to 1500 to 2000 feet by next Sunday and Monday with high and morning coastal low clouds extending inland to the western valleys. && .AVIATION... 070900Z....Coast/Valleys..Low clouds 900-1400 ft MSL have filled 10- 15 miles inland. Local visibility restrictions 2-5 SM will occur where clouds intersect with elevated coastal and western valley terrain. Stratus deck will scatter and clear 15-17Z Monday morning. Patchy low clouds 700-1200 ft MSL reform again late Monday evening, likely moving ashore 05-08Z Tue. Mountains/Deserts...Mostly clear with unrestricted VIS through Tuesday. && .MARINE... A robust onshore push Tuesday afternoon will bring NW wind gusts approaching 20 kts in the outer waters. Otherwise, no hazardous marine weather is expected through Thursday. && .BEACHES... Long period southerly swell generating 4-6 ft surf for south facing beaches will gradually subside through Monday. Strong rip and longshore currents at all beaches expected through Tuesday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Thursday for Coachella Valley-San Diego County Deserts. PZ...None. && $$ PUBLIC...17 AVIATION/MARINE/BEACHES...Westerink