San Diego Forecast Discussion

000
FXUS66 KSGX 280357 AAA
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
900 PM PDT Tue Sep 27 2022

.SYNOPSIS...
Hot conditions will continue across the region through tomorrow.
Increasing moisture will lead to a slight chance for showers and
thunderstorms on Wednesday across the mountains, High Desert and
eastern portions of the inland valleys. Greater cooling is expected
for Thursday through the weekend.

&&

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

Evening Forecast Update:

No updates were needed this evening. Low clouds will begin to form
towards midnight near the coast and spread inland a few miles
through Wednesday morning.

Previous Discussion (issued at 155 PM PDT):

For Wednesday, increasing moisture will lead to a slight decrease in
temperatures by a degree or two region-wide, though highs will
remain well above seasonal averages. This will continue to lead to
moderate to locally high heat risk across the region. Scattered
showers and thunderstorms will be possible through the afternoon,
mainly across the mountains, High Desert and eastern portions of the
inland valleys. The main threat will be frequent lightning and gusty
winds, though heavy rainfall leading to local flooding will be
possible.

The ridge will weaken on Thursday as an upper-low moves through the
Pacific Northwest. Onshore winds and drying conditions are
anticipated for Thursday through the weekend, allowing for cooler
temperatures. By Saturday, high temperatures are expected to be near
or slightly below average west of the mountains, and slightly above
in the deserts.

The 12z ECMWF Ens Mean shows ridging moving into the western United
States for the second half of the weekend, with positive height
anomalies returning to Southern California Sunday night into Monday.
This may lead to slight warming early next week.

&&

.AVIATION...
280400Z...Clear for areas 15+ miles inland tonight. Moderate
confidence in cigs forming near the coast 10Z-17Z Wednesday, highest
chance at KSAN/KCRQ. BKN-OVC cigs 004-007 ft MSL and vis 1-4SM in BR
expected, locally lower vis near higher terrain. TCU with tops near
30-40K ft MSL expected across the mountains after 19Z Wed with ISO
TSRA. Gusty and erratic winds with heavy downpours possible near
storms until 02Z Thursday.

&&

.MARINE...
No hazardous marine weather is expected through Saturday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT Wednesday for Orange County Coastal
     Areas-San Diego County Coastal Areas-San Diego County
     Valleys-Santa Ana Mountains and Foothills.

     Excessive Heat Warning until 8 PM PDT Wednesday for Coachella
     Valley-Orange County Inland Areas-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Deserts-San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...Schenk/JMB
AVIATION/MARINE...APR

NWS SGX Office Area Forecast Discussion