Area Forecast Discussion
Issued by NWS San Diego, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
FXUS66 KSGX 262044
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
144 PM PDT Tue Mar 26 2024

.SYNOPSIS...
A weak ridge will move over the southwestern part of the country,
leading to our warmest day of the week. This will be short-lived
as a strengthening low pressure system from the north moves into
the area later this week. Out ahead of it, cooling will take place
by Thursday and Friday with windier conditions for mountain and
desert regions. The weekend looks like another wet one, where
SoCal will be impacted by bouts of heavy rain and mountain snow.
Drying will slowly occur by early next week as the system departs.

&&

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

.SHORT TERM (Today through Friday)...
Broad northwest flow aloft is maintaining a weak coastal eddy
off the coast. This continues the partly to mostly cloudy skies
across the area, where partial clearing can be expected through
the afternoon. The marine layer will shrink slightly as a weak
area of high pressure moves into the region by Wednesday, but low
clouds and patchy fog will still move into coastal and western
valley areas. Highs will range from the 50s/60s in the mountains,
60s/70s west of the mountains and high desert areas, and near 80
degrees in the lower deserts.

Pressure falls will occur on Thursday and Friday as a potent area
of low pressure from the Pacific Northwest moves further down the
West Coast. This will bring cooling and windier conditions for the
area. Gusty winds will occur across the mountains and deserts
there is moderate to high confidence in wind gusts over 40 MPH for
typical wind-prone mountain passes including the San Gorgonio
Pass. Winds west of the mountains will not be as strong with gusts
15-25 MPH. Temperatures on Thursday will be slightly cooler on
Thursday, and noticeably cooler on Friday.

&&

.LONG TERM (This Weekend into Early Next Week)...
Taking a look at the latest model suite, probabilities increase
for precipitation sometime on Friday evening or Saturday morning.
The rain and mountain snow is coming, just a matter of exactly
when this weekend. A shortwave off the main area of low pressure
will intensify the low this weekend. Bouts of heavy rain and
mountain snow above 6,000 feet are expected, with two main waves
expected.

Late Friday night into Saturday will see one round of
heavier precipitation with another round expected on Sunday as the
trough axis deepens and moves over SoCal. As it does so, it will
be bringing in some colder air behind it, leading to the coolest
day of the week to likely be on Sunday. Highs will stay only in
the 30s and 40s across the mountains and struggle to get to 60
degrees west of the mountains. We will continue to look into the
storm threat as cooler air aloft may be able to trigger isolated
storm activity as with the passing area of low pressure. Snow
levels are still somewhat uncertain, but northern areas above
6,000 feet will likely see the most significant totals. Snow
levels will fall from 6,500 feet late Friday and Saturday to near
5,500-6,000 feet.

Model cluster guidance becomes more widespread in solutions of
the troughs departure, some leaving it linger in the area through
later on Monday or Tuesday. Depending on how this shapes up will
depend on when the cooler wetter weather will depart. NBM POPs
look reasonable with lower elevations drying out by Monday
afternoon. After this, drier and warmer weather looks to occur.

&&

.AVIATION...
262030Z...Coasts/Valleys...Areas of SCT/BKN low clouds with bases
2500-4000 feet MSL and tops to 5000 feet will continue through 03Z
Wed. Patchy BKN/OVC low clouds with bases 1700-2500 ft MSL will
occur 05Z-17Z Wed, with generally SKC/SCT clouds Wed afternoon. Most
vis will remain unrestricted below the clouds through Wed.

Mountains...Local terrain obscurations in clouds will occur on the
coastal slopes below 5000 feet MSL through 23Z. After 23Z, mostly
clear skies with unrestricted VIS will prevail through Wed.

Deserts...Mostly clear skies will continue through Wed. Westerly
winds 20-30 kt on desert slopes and locally into adjacent deserts
will occur at times through 08Z Wed, with MOD up/downdrafts and
local VIS 3-5 miles in BLDU.

&&

.MARINE...West to northwest winds late Thursday and Thursday night
and southerly winds Saturday could gust over 20 knots. Otherwise, no
hazardous marine conditions are expected through Sunday.

&&

.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...APR
AVIATION/MARINE...Maxwell


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.