Area Forecast Discussion
Issued by NWS San Diego, CA
Issued by NWS San Diego, CA
311 FXUS66 KSGX 160344 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 844 PM PDT Thu Aug 15 2024 .SYNOPSIS... Fair and seasonal weather will continue through the weekend. Stronger high pressure will bring a warming trend next week. Low clouds and fog will continue in coastal areas and western valleys during late nights and early mornings. Chances of showers and thunderstorms return around Tuesday and Wednesday in the mountains and deserts. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Skies are clear this evening as another mostly sunny day comes to a close. Low clouds and fog will gradually form overnight, eventually covering most of the coastal areas and western valleys by sunrise Friday. A coastal eddy strengthens Friday, which should give the marine layer a little boost. A similar low cloud and eddy situation is expected Saturday, while temperatures come down a few degrees. A weak low pressure trough to the north will jockey for position over SoCal with a strong high pressure ridge to the east. Next week the ridge strengthens and expands westward. This will bring a warming trend such that by Monday high temperatures will reach above normal, and by Tuesday they will reach 4 to 9 degrees above normal. Right now Tuesday appears to be the hottest day in the coming week, with highs over 100 in the Inland Empire and the high desert, and over 110 across the Coachella Valley. Monsoonal moisture will start increasing rather thin and high Friday, with not much change over the weekend. A deeper column of moisture moves in Monday and Tuesday and peaks Wednesday. This will lead to a slight chance of afternoon thunderstorms in the mountains and deserts Tuesday with a better chance of more widespread storms Wednesday. The guidance on this moisture feed will vary in coming days, but right now Tuesday and Wednesday have the greatest chance. The marine layer and low cloud situation should diminish as the ridge and the monsoon flow both peak. Many ensembles are indicating the northern trough to amplify starting next Thursday, which would decrease the monsoonal moisture and chances of storms. It would also bring a cooling trend later next week. && .AVIATION... 160330Z...Coast/Valleys...Redevelopment of patchy low clouds expected around 05-07z from south to north along the coast. BKN-OVC CIGs fill in along the coasts/valleys from 09-11z with bases around 600-900ft MSL, tops around 1100ft MSL. Localized VIS reductions below 3SM possible in BR/FG for valleys and higher coastal terrain, with VIS closer to 5-6+ SM along the immediate coasts. Any clouds/fog scatter/clear tomorrow around 16-17z Friday morning. VFR conditions prevail through Friday afternoon with patchy low clouds developing again late Friday evening. Mountains/Deserts...Mostly clear with unrestricted vis through Friday evening. FEW Cu possible Friday afternoon along the mountain peaks. && .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/Maxwell