FXUS66 KSGX 181929
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1229 PM PDT Mon May 18 2026

.SYNOPSIS...
Night and morning low clouds and fog will be present each day 
through the forecast period along the coast for the first half of 
the week and into portions of the valleys towards the end of the 
week. High temperatures will be below average in the deserts today 
and tomorrow, with highs 5 to 10 degrees above average west of the 
mountains for the first half of the week. Minor fluctuations in 
temperatures for Thursday through next weekend. 

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Weak offshore flow through Wednesday will keep low clouds out of
the inland valleys but won't be strong enough to keep coastal 
areas clear of low clouds overnight and in the mornings. It should
help with more efficient clearing in the afternoons through 
Wednesday. A noticeable warming expected today compared to 
yesterday with the inland valleys expected to be 8 to 15 degrees 
warmer. An additional 3 to 7 degrees of warming is expected on 
Tuesday from the coast to the deserts, with continued warming
inland Wednesday. 

The marine layer is expected to deepen Wednesday night into 
Thursday, which will push low clouds and fog into the inland 
valleys. A deeper marine layer is expected to be maintained through 
the weekend. There will be slight day-to-day differences in high 
temperatures for Thursday through next weekend with high 
temperatures a few to around 5 degrees above average. 

&&

.AVIATION... 181800Z...Coast/Valleys...Low clouds have cleared most 
areas in OC and the Inland Empire, with low clouds with bases 2500-
4000ft MSL clinging to inland and coastal San Diego county for 
another hour or two. Low clouds may return this evening (30-50%) to 
coastal areas with the highest chances in coastal San Diego between 
13-17Z. if low clouds do develop, bases would be AOA 1500ft MSL.

Mountains/Deserts...Northerly winds will bring gusts 25-35 knots 
through and below mountain passes through 20-22Z. Pockets of LLWS 
and downdrafts in lee (south and west) of mountains will be possible.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday.

&&

.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...Villafane