568
FXUS66 KSGX 271556
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
856 AM PDT Sun Apr 27 2025

.SYNOPSIS...
Cool and cloudy weather will continue through today, with isolated light
showers bringing periods of rain and high elevation mountain
snow. There will also be breezy southwest to west winds in the
mountain passes and adjacent desert areas, weakening this evening.
Fair and warmer weather will follow for most of next week, with
the usual marine layer low clouds during the nights and mornings.
Temperatures will then cool off again as we approach next weekend.

&&

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

The upper low pressure system that brought yesterday`s rain and
snow and wind (oh my) is currently parked over south-central
Nevada. Cyclonic flow around it is bringing a steady flow of
moisture from the Pacific Ocean that is resulting in lots of small
rain showers, mostly in Orange County and in San Diego County west
of the mountains. Precipitation totals since rain started are from
a few hundredths of an inch to about a third of an inch for
coastal and valley locations (with a few spots in Orange County
receiving up to 0.40"), a few hundredths of an inch in the
western high desert, and about a quarter inch to an inch of rain
(or liquid equivalent above the snow line) for the mountains.

There will be a slight chance for showers somewhere in the region
through the rest of today, but where that place is will vary.
Light showers will continue to be possible for Orange and San
Diego counties through early this afternoon before tapering off.
Late in the afternoon through the evening, isolated showers could
develop over the mountains. Snow levels will be rising through the
day from about 5000 feet this morning to 6000 to 7000 feet late
this afternoon, so snow will generally be restricted to the peaks.
A few showers popping up again over the San Diego County valleys,
generally in the southern parts of the county, are also not out
of the question late in the evening through early morning Monday.
These showers will continue be light, resulting in a few
hundredths of precipitation for areas they cross.

Any last shower(s) will taper off by mid-morning Monday as the
upper low moves eastward and the atmosphere aloft dries out behind
it. Meanwhile, calmer winds this morning will strenghten again
this afternoon over the desert slopes of the mountains into the
deserts, though not nearly to the extent of yesterday`s winds,
with intermittent gusts up to 50 mph through the particularly
wind-prone passes. Winds taper off this evening and then calm
overnight.

Weaker troughing/low pressure aloft will continue to linger over
the region Monday and part of Tuesday, keeping temperatures 5 to
10 degrees below average Monday. Despite that, afternoon high
temperatures Monday will be noticeably warmer than today away from
the immediate coast, where warming will be less significant. This
trend will continue Tuesday, and afternoon high temperatures will
warm to near normal region-wide, plus/minus a few degrees. Not
much difference Wednesday compared to Tuesday as weak ridging
aloft hangs in there for most of the day. Winds will be fairly
sedate early next week, with average springtime afternoon and
evening breezes. Marine layer low clouds will develop at least in
areas each night and morning, though they`ll be shallower and
closer to the coast in extent both Monday night through Tuesday
morning and Tuesday night through Wednesday morning.

A weak low aloft moves into southern California early Thursday
morning, which will deepen the marine layer and could result in
some patchy drizzle out of it Thursday morning, but otherwise
won`t have much affect on temperatures or winds Thursday.
Temperatures will then gradually cool each day Friday through the
end of the week as the weak low gets pushed out by a stronger
system approaching from the northwest. Nightly and morning low
clouds will continue to deepen and get further inland overnight
through the end of the week.

Ensembles are in pretty good agreement with regards to a stronger
trough moving down the west coast into California Saturday into
Sunday, but clustered 500 mb heights have differences in specific
positioning and strength of the trough, which will affect degree
of cooling, strength of winds, and precipiation. Temperatures
nonetheless are expected to be slightly below average Friday,
then below average Saturday and Sunday. Afternoon/evening breezes
will likely strengthen slightly from Thursday to Friday, with
stronger winds over the mountains and deserts Saturday and Sunday.
Model ensembles continue to show pretty good agreement in light
precipitation around Sunday into early next week.

&&

.AVIATION...
271522Z....Coasts/Valleys/Coastal Mountain Slopes...SCT-BKN clouds
with bases 3000-6000 ft MSL through this evening with higher terrain
locally obscured. Local VIS 3-5 miles and local BKN-OVC bases 2000-
3000 ft MSL in -SHRA through 20Z Sun, but most VIS will remain
unrestricted below the clouds. After 06Z Sun, BKN-OVC with bases
around 1500-2500 ft MSL.

Mountains/Deserts...Occasional west winds with gusts 20-35 kt will
continue through this evening, mainly from the mountain crests east
through the desert mountain slopes and locally into the deserts,
including below mountain passes. SCT -SHRA/-SHSN will occur in the
mountains through this afternoon, with occasional mountain
obscurations in clouds. Some clearing will occur by later this
evening and SHRA/SHSN will continue to taper off overnight into
early Monday morning.

&&

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

&&

.BEACHES...
Elevated surf of 3 to 6 feet with sets to 7 feet will occur through
Wednesday. Highest surf will occur on south facing beaches. Strong
rip currents are expected.

&&

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Wednesday evening for Orange
     County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...CSP
AVIATION/MARINE/BEACHES...CO