154 FXUS66 KSGX 062046 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 146 PM PDT Sun Jul 6 2025 .SYNOPSIS... High pressure will strengthen over the area by the middle of the week, leading to hotter weather for inland areas. The marine layer will become shallower, leading to low clouds and patchy fog near the coast each night and morning. The high pressure will weaken slightly, keeping the deserts slightly warmer than average and closer to average elsewhere. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Our area continues to be sandwiched in between low pressure off the Central Coast and high pressure NW Mexico (Sonora, Chihuahua). This continues to keep us right near average for this time of year with elevated onshore winds across mountain passes and adjacent deserts 20-35 mph. The area of low pressure will stick around one more day where the marine layer will be fairly similar to what it was this morning with far western valleys and coastal areas seeing low clouds and fog. The high pressure system over Mexico will strengthen into Tuesday, causing the marine layer to become shallower and keep clouds/fog confined closer to the coast. As the high provides greater influence over the region, we can expect temperatures for inland areas to nudge up a couple degrees. Lower level moisture will also creep into SoCal, where higher humidity will be felt Tuesday through Thursday. Models show the high continuing to amplify on Wednesday and Thursday as it moves over our region. This will lead to the hottest temperatures of the week with highs reaching near 5 to 10 degrees above normal. Confidence on highs reaching 115 are moderate as influxes of low level moisture can make for a tricky high temperature forecast; though whatever the outcome, it will feel hotter and humid by the middle of the week. Please take extra precautions if you must be outside for long periods or do not have adequate cooling/hydration methods. As the high peaks in strength, high temperatures have a moderate to high chance of reaching 100 degrees across the Inland Empire and high desert. Widespread 90s are in the forecast for inland valleys of Orange and San Diego counties, though some spots in the SD co valleys may reach near 100 degrees. Make sure to only recreate outdoors in the early mornings or evenings in the mountains as well, since highs will be in the upper 80s to upper 90s from Idyllwild to Julian. Models are in fair agreement of the area of high pressure weakening slightly but staying over our region into next weekended. This will continue a fairly thinner marine layer with low clouds and fog closer to the coast. Also if this occurs, most areas will cool with high temperatures near average except the deserts, which will stay near 5 degrees above normal. && .AVIATION... 0601930Z....Coast/Valleys..CLear conditions will continue through the remainder of the daylight hours. Low clouds 900-1400 ft MSL will reform and move ashore again after 04Z Mon. Local visibility restrictions will occur where clouds intersect with elevated terrain. Breakup of the marine layer inversion and associated stratus deck is expected to occur between 15Z-17Z Monday morning. Mountains/Deserts...Mostly clear with unrestricted VIS through Monday. && .MARINE... No hazardous marine weather conditions are expected through Wednesday. && .BEACHES... Southerly swell (190 degrees) of 3 to 4 feet at 14-16 seconds will generate elevated surf of 4-6 ft with sets to 7 ft along south facing beaches through Sunday evening. In addition, strong rip and longshore currents are expected at all beaches through Sunday. A Beach Hazards Statement is in effect and contains more information. Surf may remain elevated into early next week. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement until 11 PM PDT this evening for Orange County Coastal Areas-San Diego County Coastal Areas. Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Thursday for Coachella Valley-San Diego County Deserts. PZ...None. && $$ PUBLIC...APR AVIATION/MARINE/BEACHES...Suk