Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
524 FXUS66 KSGX 011548 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 848 AM PDT Sat Nov 1 2025 .SYNOPSIS... Warm weather will continue through the weekend with night and morning low clouds and fog along the coast and far western valleys. A trough of low pressure to the north will bring cooler weather across the region by next week, as well as greater coverage of marine layer low clouds. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .Morning Update... Mostly clear skies inland with clouds and fog closer to the coast are seen on satellite this morning. Clouds will begin to scatter out of the valleys over the next hour or two with clearing to the coast by late morning. Weak offshore flow and warm temperatures will continue over the weekend before greater cooling spreads across the region next week with a deeper marine layer. Otherwise, no changes to the forecast! .Previous Discussion (250 AM Saturday)... Marine layer low clouds continue to spread into inland Orange County and the far western valleys in San Diego County. Visibility at the coast is much better than yesterday, though locally dense fog is being reported in the valleys. Low clouds and fog will gradually clear to the coast during the mid to late morning as offshore flow develops. This event will be very weak, with gusts even in the wind-prone areas topping out at around 25 mph. Offshore flow and upper level ridging over the region today will bring another warm day to start the month, with high temperatures around 8-12 degrees above normal away from the coast. The marine layer will remain shallow tonight into Sunday morning, with low clouds and locally dense fog developing once again. A weak cut-off low off the coast of So Cal will move over the area as it becomes an open wave on Sunday, bringing minor cooling and some scattered high clouds late in the afternoon, perhaps in time for some nice color during the one hour earlier sunset. Mostly zonal flow will be in place across Southern California for the remainder of the week with a pair of short waves moving inland to the north Wednesday and Friday. Ensembles have trended towards a lower-amplitude solution for the mid-week wave, bringing our already low precipitation chances down to zero for the Wed/Thu time frame. Best we can possibly do is some marine layer drizzle Thu morning, but even that is looking less likely. This pattern will produce a gradual cooling trend and a deeper marine layer through Wed/Thu, along with an increase in westerly winds across the mountains and deserts, strongest Wednesday afternoon into Thursday as onshore gradients peak. Surface gradients turn offshore to the north on Friday, but with a lack of upper level support expect this to be another low- end Santa Ana event that will bring more heat than wind. && .AVIATION... 011545Z...Coasts/Valleys...Low clouds (based near 400-700ft MSL) have stretched about 15 miles inland this morning. Greatest VIS restrictions (less than 1SM) located on the eastern portions of the clouds while the coasts are seeing VIS closer to 4-6 SM. These clouds will gradually lift over the next few hours allowing VIS to improve. Scattering/clearing will begin around 16-17z, with full clearing to the beaches/coast by 19z Saturday. However, low clouds (based around 1000-1500ft MSL) may linger over beaches and just offshore through the afternoon hours. The low clouds will push back ashore after 00-01z Sunday, filling back in through 15 miles inland. Bases will initially be around 1000-1500ft MSL but should settle down to 600-900ft MSL after 06z Sunday. As with this morning, VIS along the coast should only fall to 4-6SM or higher with higher coastal terrain and inland valleys seeing VIS closer to 1-3SM, locally under 1SM at times. 30% chance of LIFR CIGs/FG reaching KONT between 09-16z Sunday. Mountains/Deserts...VFR conditions prevail through the period. && .MARINE... No hazardous marine concerns through Wednesday. && .BEACHES... Long period (19-21 sec) swell from the southwest (200 degrees) today, prevailing into Sunday, bringing elevated surf of 3 to 5 feet with locally higher sets on southwest facing beaches. Surf will gradually fall Sunday into 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. && $$ UPDATE...APR PUBLIC...SS AVIATION/MARINE...Munyan