951
FXUS66 KSGX 280427
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
930 PM PDT Sat Apr 27 2024

.SYNOPSIS...
Dry warmer will continue through Tuesday with mostly near to
slightly above average temperatures. The marine layer will be
shallower, with night and morning low clouds and patchy fog more
confined to coastal areas. There is some uncertainty in the forecast
for the second half of the week, but dry conditions are expected
with a potential for further warming.

&&

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

Update...

We still have patchy low clouds at mid-evening in the foothills of
the mountains, mainly in San Diego County, with clear skies
elsewhere. These clouds should dissipate overnight with only patchy
low clouds developing near the coast, mainly in San Diego County.
There are still some moderately windy areas, but more localized than
on Friday evening, with White Water RAWS in San Gorgonio Pass having
a recent gust of 43 MPH with most other windier locations in the
northern part of the Coachella Valley, desert mountain slopes and
parts of the high deserts of San Bernardino County. These winds will
gradually weaken overnight. Sunday will be mostly sunny and mostly
around 5 degrees warmer, with highs back above 90 in the lower
deserts.

From previous discussion...

Dry conditions are expected through the rest of the weekend with
weaker winds and sunnier skies for much of Southern California. Weak
high pressure aloft is expected into early next week, which will
bring temperatures near to slightly above average for Sunday through
Tuesday. Highs in the upper 60s expected near the coast, with highs
in the upper 70s and low 80s in the valleys, and highs in the 90s in
the lower deserts.

The backside of the trough is still close enough to Southern
California today to enhance the onshore pressure gradient and
afternoon sea breeze. West to northwest winds across mountains and
deserts will have peak gusts of 25-40 MPH through this evening.
Winds will be slightly higher through the San Gorgonio Pass, with
local gusts up to 55 mph possible. Onshore winds will continue to
weaken into Sunday and early next week as weak high pressure aloft
prevails. Periods of weak offshore flow may develop Tuesday morning
near mountain foothills and below passes locally into the valleys.

A trough of low pressure aloft is expected to move across the
Intermountain West Wednesday, further weakening the already weak
high pressure over California. This will mean a few degrees of
cooling for most areas on Wednesday and the potential for additional
rounds of breezy westerly winds over the mountains, through passes,
and into the deserts. There is still some uncertainty surrounding
the wind forecast due to uncertainty in the placement and amplitude
of the passing trough. If the trough digs south into the Great Basin
(supported by about a quarter of the ensemble solutions) that would
bring stronger winds to Southern California in addition to the few
degrees of cooling.

Uncertainty in the global models remains for the end of next week.
For Thursday and Friday there remains some disagreement surrounding
the potential for high pressure aloft to rebuild over the West Coast
in the wake of the aforementioned trough. About a quarter of the
global ensemble solutions have a ridge building over the West Coast
for Thursday and Friday. The remaining solutions are more in favor
of a prevailing troughing pattern. The majority of solutions that
support troughing are indicating conditions will remain dry into
next weekend. If the troughing pattern materializes, then cooler
conditions with periods of enhanced westerly winds over the
mountains, through passes, and into the deserts can be expected
through the end of the week. If the ridging pattern materializes,
then warming conditions can be expected for the end of the week,
with periods of weak offshore flow. Current forecast for the end of
the week closely follows the NBM.

&&

.AVIATION...
280355Z...Coast/Valleys...SKC-SCT020 through 08Z. 08-16Z...areas
BKN015-025 within 10 miles of the coast. After 16Z...mostly clear.

Mountains/Deserts...Mostly clear tonight and Sunday. Gusty northwest
winds 15-35 kt through 12Z.

&&

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

&&

.BEACHES...
A mix of NW and SW swells will generate surf of 3-5 feet Sunday and
Monday and a high risk of rip currents.

&&

.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...Maxwell (Update)/CO (Previous Discussion)
AVIATION/MARINE/BEACHES...Moede