419 FXUS66 KSGX 160413 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 913 PM PDT Sun Jun 15 2025 .SYNOPSIS... A gradual cooling trend starts Monday and continues through most of the week with the possible exception of Wednesday. Night and morning low clouds and fog can be expected each day along the coast, reaching into portions of the valleys for the middle to end of the week. Breezy west winds across the mountains and deserts each afternoon and evening, strongest on Monday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .UPDATE... No significant changes from the forecast. Temperatures this afternoon over-preformed for many location, especially along the 15 corridor in San Diego County, where highs generally ranged from 90-102 due to a brief reprieve from the seabreeze and wind shift to the south. Limited records were broken today despite the abnormally hot weather, even the 117 at Palm Springs fell short of the record of 120 degrees set back in 2021. Temperatures peaked today with strong ridging over the area, but a flattening ridge into mid week will promote a slow cooling trend, with highs generally still above normal for mid June. Clusters continue to support this pattern, with troughing returning by the weekend to cool temperatures further. Unfortunately, there remains no significant precipitation on the horizon. .PREVIOUS FORECAST FROM 119 PM... Temperatures at 1 PM were running mostly 5 to 10 degrees warmer than 1 PM yesterday across the area. Widespread moderate HeatRisk is impacting the inland valleys, mountain foothills, and High Desert today, with moderate to locally major HeatRisk in the low desert. Make sure you`re staying hydrated and seeking shade if you`re spending time outdoors. If possible, avoid strenuous outdoor activity during the hottest part of the day (through 5pm). The ridge of high pressure over us today will begin to flatten Monday as an upper level trough moves inland across the West Coast. That will kick off a gradual cooling with highs Monday a few degrees cooler than today and additional cooling into Tuesday. Even with highs being knocked down a few degrees, they will remain 3 to 7 degrees above average Tuesday. In addition to a few degrees of cooling, onshore flow will strengthen. That will bring breezy west winds to the desert mountain slopes, below the passes, and into the deserts during the afternoons and evenings. Strongest winds are expected Monday with gusts 30 to 45 mph, locally up to 50 mph through the San Gorgonio Pass. Low clouds are expected to remain persistent each night and morning for the coast early this week, with areas of locally dense fog possible. The marine layer is expected to deepen for the middle to end of next week as a more amplified trough of low pressure approaches the West Coast. Global ensemble clusters show a brief rebound in the ridge for Wednesday, which will bring a few degrees of warming to inland areas. NBM chances for the Inland Empire to exceed 100 degrees is 30 to 60 percent, with the higher chances in the eastern portions of the Inland Empire. In the low desert, NBM has a 60 to 80 percent chance of high temperatures exceeding 110 degrees. In the High Desert chances of exceeding 100 degrees are 70 to 80 percent. The warming on Wednesday will be short lived as there is good ensemble agreement in a more amplified trough moving into the Pacific Northwest Thursday through the weekend. While there is still some uncertainty in the finer details cooler conditions, increased winds, and a deeper marine layer can be expected for the end of the week. There is high confidence in dry conditions with this passing trough. && .AVIATION... 160330Z....Coast/Valleys...Low clouds are redeveloping offshore this evening. These are expected to push onshore after 06Z tonight, initially across southern coastal San Diego County, then pushing northward and inland to 10-15 miles through 13Z. Bases may start out around 500-800 ft MSL but then lower to 300-600 ft MSL, with vis 1-4 SM for coastal TAF sites. Clouds clearing to beaches 16-17Z Mon, followed by clear skies. Low clouds with similar bases and vis expected to develop again after 06Z Tue, but with patchier coverage. .Mountains/Deserts...FEW-SCT high clouds and mostly unrestricted VIS prevail through Monday. West winds strengthening after 18Z Mon, with wind gusts 20-30 kts, locally near 40 kts through the San Gorgonio Pass, leading to MOD UDDFS 21Z Mon-08Z Tue. && .MARINE... Wind gusts up to 20-25 kts possible in the outer waters Monday afternoon near San Clemente Island. Otherwise, no hazardous marine conditions are expected through Thursday. && .BEACHES... A 3 foot southerly (190 degrees) swell at 17-18 seconds will continue to produce elevated surf of 3 to 6 feet with local sets up to 7 feet, primarily for Orange County and northern San Diego County beaches. A Beach Hazard Statement remains in effect through late this evening. Swell and surf heights wane late tonight into Monday. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement until 11 PM PDT this evening for Orange County Coastal Areas. PZ...None. && $$ PUBLIC...Zuber AVIATION/MARINE/BEACHES...CSP