995 FXUS66 KSGX 140409 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 909 PM PDT Fri Jun 13 2025 .SYNOPSIS... Temperatures expected to fluctuate between periods of warming and cooling into next week. Overall, temperatures will stay 5 to 10 degrees above average at their warmest and around 5 degrees above average at their coolest. Night and morning low clouds and fog can be expected each day and will reach into portions of the valleys. Slight increase in westerly winds expected over the mountains and into the deserts early in the upcoming week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Update: Models have remained nearly consistent in terms of the overall pattern through the weekend. The ridge is going to continue to strengthen and allow for temperatures to warm up substantially. Father`s Day (Sunday) is still looking to be the warmest day of the week. The marine layer will also continue to thin and lower going into the weekend, with less coverage. There will be higher clouds passing by tomorrow, which will keep it partly to mostly cloudy for most locations, despite lower level clouds eroding out by later in the morning for most of the coastal and inland areas, as the PBL remains very dry. There could be a few areas right along the immediate coastline that go periodically broken with lower level clouds. Otherwise, beyond that, models also continue to show a longwave trough edging in towards the region and allowing for a gradual cooldown to occur going into the middle of next week. (Previous discussion submitted at 117 PM): At 1 PM, low clouds had cleared from inland areas but are continuing to linger along area beaches. Low confidence in complete clearing at the beaches this afternoon, with partial and intermittent clearing most likely. Low clouds and fog are expected to remain persistent each night and morning for the coast and into portions of the valleys into next week. High pressure will build from the south this weekend bringing an increase in high temperatures, peaking on Sunday. Highs Saturday will be 3 to 5 degrees warmer than today. By Sunday, high temperatures will be around 5 degrees above average near the coast and 10 degrees above average further inland. NBM chances for the low desert to exceed 115 degrees on Sunday is around 15 percent, with an over 90 percent chance of high exceeding 110 degrees. West of the mountains, there is a 50 to 80 percent chance of portions of the Inland Empire exceeding 100 degrees and a 30 to 50 percent chance portions of eastern San Diego County valleys exceeding 100 degrees Sunday. Portions of inland Orange County (east of Interstate 5) have a 30 to 50 percent chance of temperatures exceeding 90 degrees. A low pressure system moving inland through California on Monday will strengthen onshore flow for Monday and Tuesday. This will result in a slight increase in westerly winds over the mountains and into the deserts. In addition, slight cooling will spread inland on Monday and Tuesday. By Tuesday high temperatures will be around 5 degrees above average. Wednesday will see a few degrees of warming as the ridge rebounds in the wake of the passing trough with cooler conditions expected Thursday and Friday as a stronger, deeper trough digs into the Pacific Northwest. && .AVIATION... 140400Z....Coast/Valleys...Low clouds based around 1000-1500 feet MSL will lower to 600-100 feet MSL and push up to 10-15 miles inland 04-06z. Low clouds briefly settle over the western Inland Empire 09- 14z. Vis locally reduced 0-5 SM along higher coastal terrain and for some inland valleys. Clearing Saturday morning 15-16Z inland and 17- 19Z for the coast, with some patchy low clouds lingering along the immediate coast. Low clouds redevelop and push inland again 03-05z Sunday. Otherwise...SCT high clouds and unrestricted vis tonight and Saturday. && .MARINE... No hazardous marine conditions are expected today through Wednesday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ UPDATE...Stewey PUBLIC...CO AVIATION/MARINE...Westerink