000
FXUS66 KSGX 222035
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
135 PM PDT Fri Sep 22 2023

.SYNOPSIS...
Areas of sprinkles to locally light rain through tonight. In areas
where rain accumulates, amounts of less than a tenth of an inch are
expected. Dry conditions are expected to return for this weekend.
There will be a gradual warming trend over the weekend into next
week but temperatures will remain near to slightly below average.
Areas of low clouds and fog will be confined to coastal areas for
late in the weekend into the middle of next week.

&&

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

Since this morning a few locations mainly in San Diego County, have
recorded less than 0.05 inches of rain. As of 1 PM, San Diego
International Airport was the big winner with 0.03 inches of rain
measured over the past 12 hours. Radar reflectivity continues to
show areas of sprinkles and light precipitation in San Diego County.
Forecast composite reflectivity from high resolution model guidance
is showing areas of sprinkles and light showers spreading north into
Orange County, the Inland Empire, the Riverside County mountains,
and the low deserts later this afternoon. Chances become more
confined to the mountains and lower deserts this evening into the
overnight hours. For places that get accumulating rain, totals are
still expected to be a tenth of an inch or less and passing rain
showers should be short lived.

Dry conditions are expected by Saturday with decreasing high cloud
coverage. Weak ridging will prevail over Southern California this
weekend into next week. This will result in a gradual warming trend
that will peak mid-week. Even with the warming, temperatures for
most places will remain at to just below average for this time of
year. Marine layer low clouds and fog are expected to return by
Sunday morning. Night and morning low cloud coverage will remain
mostly confined to coastal areas for much of next week.

Global model guidance is indicating a deeper trough impacting the US
West Coast for late next week into next weekend. This is just
outside of our official forecast period but some guidance is
indicating the trough could dig far enough south to impact Southern
California. At the very least cooler, windier weather with a much
deeper marine layer is expected. There are some ensemble members for
the ECMWF and GFS that are showing precipitation. There remains
quite a bit of uncertainty in the model solutions with most ensemble
members remaining dry at this time, but it is something to watch
moving forward.

&&

.AVIATION...
221930Z...Coast/Valleys/Foothills...Multiple cloud layers with FEW-
SCT 2000-2500 feet MSL, SCT-BKN 3000-3500 feet MSL and BKN at/above
10,000 feet MSL. Isolated DZ/-SHRA through this evening with vis
reduced to 1-3 SM. Low cloud development overnight will be minimal,
if at all. If any ceilings do form, they would be patchy and
confined to the coast. Low confidence in ceilings at coastal
terminals.

Mountains/Deserts...SCT-BKN at/above 10,000 feet MSL through
tonight. DZ/-SHRA possible over mtns through this evening with vis
reduced to 1-3 SM.

&&

.MARINE...
Breezy northwest winds may create rough boating conditions near the
entrance of the San Diego Bay Saturday afternoon. Northwest winds
with gusts approaching 20 kts in the outer waters are expected each
afternoon early next week.

&&

.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...Connolly