Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
225 FXUS66 KSGX 102155 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 155 PM PST Mon Nov 10 2025 .SYNOPSIS... Warm conditions expected today with periods of weak to locally moderate northeast to east winds. Patchy dense fog is expected for the coast and western valleys tonight into Tuesday morning. Cooler conditions expected for the middle to end of the week. A windy and wet pattern is expected Thursday through Saturday. Dry conditions likely by Sunday, with additional potential for rain early next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... At 1 PM, visible satellite was showing areas of low clouds along portions of the immediate coast. High clouds just offshore are expected to move east over much of the area into Tuesday. Areas of dense fog are possible again tonight into Tuesday morning from the coast into portions of the western valleys. The most likely locations for dense fog will be on the coastal mesas and near higher coastal terrain. It`s possible that the incoming high clouds could inhibit widespread dense fog formation. An area of low pressure currently 1400 miles west of San Diego will slowly begin to move east today. This slow eastward progression will begin to weaken the ridge of high pressure over the area by Tuesday. As the upper level pattern begins to shift, the surface offshore pressure gradient will weaken and begin to transition back onshore. Influence from the offshore flow and a fairly robust high pressure aloft have kept high temperatures a few degrees warmer than 1 PM yesterday. As the high weakens, conditions will begin to cool for Tuesday. Highs Tuesday will be 3 to 6 degrees cooler than today west of the mountains. Cooler conditions will continue to spread further inland Wednesday. As the onshore pressure gradient continues to increase for the middle of the week, dense fog will become less likely for coastal locations. There is becoming better agreement in model guidance for the incoming low pressure system, particularly when it comes to the onset of the precipitation. Most guidance is indicating that precipitation will begin as early as Thursday afternoon and evening with decreasing chances for showers for Friday afternoon into Saturday. Through Friday, NBM has a 70 to 90 percent chance for one- quarter inch or more of rainfall from the coast to the mountains with a 25 to 45 percent chance of 2 inches or more for the mountains. When the cold front initially passes through Thursday evening/overnight there are chances of isolated thunderstorms to develop. Snow levels above 10000 feet will lower to 6000 to 6500 feet by Friday morning. For early Friday, the NBM 25th percentile snow level is 4500 to 5500 feet with the 75th percentile snow level 6000 to 7000 feet. NBM for Big Bear has a 60 percent chance for 1 inch or more of snowfall and a 15 percent chance for 6 inches or more. Winds are also expected to increase for Thursday into Friday. Gusts of at least 50 to 60 mph are looking likely over the mountains and into the deserts, with the potential for wind speeds to increase as we get closer especially for wind prone locations. NBM chances for precipitation are slow to taper off into Saturday, with rainfall for Friday afternoon through Saturday expected to be scattered in coverage. Dry conditions are expected by Sunday, with high temperatures remaining around 5 degrees below average. Ensemble guidance is indicating the potential for additional precipitation early next week. && .AVIATION... 102100Z...Coasts/western Valleys...Low clouds and FG will linger at beaches and over nearshore waters through this afternoon. Clouds based 400-800 ft MSL return to coastal San Diego County 00-03Z, expanding later to include coastal Orange County and pushing up to 10 miles inland. Bases should lower some overnight and coverage may become patchy at times. Areas of dense FG (1/4 SM) along elevated coastal terrain and in western valleys with vis reductions (1-3 SM) at sea level. However, patches of dense FG will remain possible at sea level. Clouds and FG retreat to the coastline 15-17Z Tue. Inland Valleys/Mountains/Deserts...VFR conditions and SCT high clouds AOA 10 kft through Tuesday afternoon. Localized east to northeast winds 20-30 knots through passes and coastal slopes through 00Z Tue. && .MARINE... Areas of low clouds and fog linger over outer coastal waters this afternoon. FG expands in coverage once again this evening with areas of visibility less than 1 nautical mile through late Tuesday morning. A storm system is expected to bring stronger winds and higher seas for late Thursday through Friday. Gusts of 20 to 30 knots expected with steep and choppy seas 7 to 10 feet. There is also a slight chance of thunderstorms Thursday evening. && .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...CO AVIATION/MARINE...KW