Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
882 FXUS66 KSGX 070507 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 907 PM PST Sat Dec 6 2025 .SYNOPSIS... Patchy low clouds and fog possible in the coastal areas tonight and Sunday night. Increasingly warm and dry conditions are in store for next week with periods of weak to locally moderate Santa Ana winds. Tuesday will likely be the warmest day with temperatures 15 to 20 degrees above seasonal averages in the inland valleys. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Today was another relatively warm day with the sea breeze making a return and pushing more moist air a few miles inland. Dew point temperatures are generally a few degrees higher than at this time yesterday and skies are clear, although patches of low clouds and fog are developing over the coastal waters. The high-resolution models are indicating a 15-25 percent chance for patchy dense fog in the coastal areas...mainly between midnight and about 2 am. From the previous discussion... Over the next few days, the broad upper high pressure area currently a few hundred miles west of San Diego will slowly expand east to cover California, then amplify northward, cutting off what is left of the onshore flow and warming temperatures up to 10-20 degrees above average by Tuesday. Highs likely above 80F just a few miles inland of the coast. From Tuesday through Friday, confidence is high that the ridge will keep its general positioning over the Western US. For each of these four days, around a 30% chance for high temperatures to exceed 85F in the inland valleys. Next Saturday and onward, most model guidance show either weakening of the ridge, or progression of the ridge into the interior US causing temperatures to cool down slightly but without a significant pattern change until at least the following week. Meanwhile, a surface high pressure will develop over Colorado on Sunday behind the broader trough throughout the eastern US, driving a modest 10-15 mb pressure gradient between Southern California and the interior US. Offshore (E/NE) Santa Ana winds pick up Sunday afternoon through the passes, then expand to coastal slopes Monday, remaining elevated through at least Thursday as long as the surface gradient persists. During this period, wind gusts of 30-45 mph, locally up to 50 mph are possible each day for the passes and coastal slopes. The intensity of the winds will vary slightly day to day and will be generally strongest in the mornings. Daytime humidities inland will drop into the 10-20% range during the afternoons, only recovering into the 30-40% range at night. In the case that the ridge weakens or moves east by the end of the week, onshore winds may prevail again Saturday onward. && .AVIATION... 07430Z....Low clouds/fog have the potential to develop along the immediate coast later tonight. Chances are 10-20% in San Diego County through 12Z Sun and 20-30% in Orange County through 14Z. Areal coverage of any low clouds/fog will be patchy with bases less than 500 ft and visibility 1 mile or less. Confidence is not high enough in VIS restrictions to include fog in the TAFs at coastal sites at this time. VFR conditions will prevail for inland areas through the TAF period. && .MARINE... There is a 10-20% chance of dense fog with visibility 1 nautical mile or less developing overnight tonight into Sunday morning. && .BEACHES... Morning high tide is predicted to be 6.5 to 7 ft on Sunday at 10 AM in La Jolla and at 9:50 AM in Newport Beach. Very high tides may result in tidal overflow in normally dry beach areas. High tide is predicted to fall below 6 ft by Monday. && .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...PG AVIATION/MARINE/BEACHES...APR