Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
114 FXUS66 KSGX 102033 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 133 PM PDT Sat Aug 10 2024 .SYNOPSIS... Strong high pressure aloft and monsoonal moisture will bring hot weather inland today, with a chance of thunderstorms over the mountains and portions of the deserts. Slightly cooler Sunday with continued chances of thunderstorms over the mountains and deserts. Drier with near normal temperatures Monday through the end of the week. Patchy low clouds and fog will gradually increase for the coastal areas each night and morning. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... NKX Radar (San Diego) is currently inoperable, probably through at least Sunday. We regret the missing surveillance. We`ve got mostly sunny skies today except for the mountains so far. There, cumulus clouds are towering and should continue to grow into some thunderstorms that could drift into the desert into early evening. A weak inverted trough aloft has brought the monsoonal moisture and chance of thunderstorms this weekend. Sunday`s chances and coverage and timing appear very similar to those of today. Any storm could produce localized flash flooding and/or strong, gusty winds. The monsoonal moisture gradually decreases late Sunday through Tuesday, and we have no tstorms in our forecast beyond Sunday. High pressure aloft peaks today and so will the temperatures, producing a fairly high heat hazard inland. Max temps will top out in the 110s in the low desert and 96-108 in the high desert and Inland Empire. Tonight will be another warm one with little relief. Then temps go tepidly downhill, gradually returning to around normal by Monday. Coastal low clouds and fog will remain rather patchy tonight, however a coastal eddy appears to develop Sunday, which may encourage the marine layer to recover from the damage caused by the current high pressure and monsoon flow. The high pressure aloft weakens under the influence of a deeper trough to our northwest Sunday and Monday. This will help maintain near-normal temps for most if not all of next week. It will also help the marine layer recover more for greater coverage of coastal clouds during the nights and mornings. There is a slight rebound of high pressure aloft for Wednesday and Thursday that could boost temps a couple degrees. There are hints of increasing monsoonal moisture toward the end of next week, but nothing to forecast about yet, and our forecast remains dry through Saturday. Latest guidance shows a little more deepening to the trough to the north, which would drop temps below normal next weekend. && .AVIATION... 102000Z...Coast/Valleys...Mostly clear conditions along the coasts and valleys aside from some thin mid-high clouds. Confidence in low stratus clouds redeveloping between 09-11z Sunday is low to medium (20%-50%) but if they move ashore, bases could be closer to 500- 700ft MSL with tops near 1000-1200ft and higher coastal terrain could see lower visibility (4-5SM). Any clouds or fog should dissipate around 15-16z Sunday. Mountains/Deserts...Cumulus with SHRA and embedded TSRA have developed across the mountains this afternoon, based near 12000ft MSL. Gusty and erratic winds possible with any storm and mod up/downdrafts near the mountains. Direct storm impacts not expected at any TAF sites. Storm chances end by 02z Sunday. More cumulus with similar base heights and TSRA chances (20-30%) possible over the mountains again after 16z Sunday. && .MARINE... No hazardous marine conditions are expected through Tuesday. && .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...MM AVIATION/MARINE...Munyan