972
FXUS66 KSGX 032017
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
117 PM PDT Thu Apr 3 2025

.SYNOPSIS...
Today and Friday will be a little warmer than recent days but
still below seasonal averages as the extensive low pressure system
persists over the western states. Isolated showers will increase
in coverage this afternoon, mainly in the mountains. There is a
slight chance of showers for Friday afternoon for the mountains
and inland valleys. Then dry and warmer for the weekend with high
temperatures warming to around average. Not much change in
temperatures for Monday with stronger onshore flow. Then warmer
for the middle of next week with high temperatures 10 to 15
degrees above average for inland areas.

&&

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

This afternoon...Shower activity is beginning to increase, mainly
over the mountains. High-resolution models continue to show the
showers increasing in coverage this afternoon/evening, with a
slight chance for tstms. Through this evening, additional rainfall
and liquid-equivalent above the snow level is expected to range
from less than one-tenth inch near the coast to one-quarter inch
and locally near one-half inch for the mountains and valleys. The
snow level will be 5000-5500 feet this afternoon/evening, with
chances for a few inches of snow above 5000 feet.

From previous discussion...
Through Saturday...The extensive low pressure that has dominated
the synoptic pattern over the western states will slowly shift
eastward through Saturday. Temperatures will gradually rise but
will likely remain below seasonal averages through Friday. There
will be a slight chance for localized showers again Friday
afternoon but conditions become drier on Saturday as a sfc high
moves into the Great Basin and weak offshore flow develops, with
north to northeast winds in the mtns, coastal foothills and
portions of the inland valleys. High temperatures on Saturday
will rise to near seasonal averages in most areas and slightly
above seasonal averages in OC and the IE.

Dry and warmer on Sunday as a ridge of high pressure moves in from
the west. Daytime temperatures will be anywhere from a few to as
much as 10 degrees above seasonal averages, reaching the low 80s
in the IE and the mid to upper 80s in the low deserts. Not much
change from Sun to Mon as the transient ridge is weakened by a
trough moving inland to the north, although coastal areas will be
a little cooler as onshore flow strengthens.

For Tue-Thu...a more robust ridge of high pressure builds over the
Southwest, with more significant warming. For Wed and Thu, daytime
temperatures will reach the upper 80s to low 90s in the inland
valleys and the upper 90s to 100 in the low deserts while coastal
areas will reach the mid 70s. These temperatures are 5 to 20
degrees above seasonal averages.


&&

.AVIATION...
032000Z...Coast/Valleys/Coastal Mountain Slopes...SCT-BKN clouds
based at 3500-6500 ft MSL with tops to 8000 ft MSL cover most of the
region, mostly BKN near foothills and in inland San Diego Co. ISO to
SCT -SHRA and isold (10-20% chance) TSRA continue through 02Z
(Riverside/north San Diego mountains through 04Z), most likely on
coastal foothills/mtns and in inland San Diego Co. Lower cigs around
2500 feet MSL and briefly reduced vis 3-5SM are possible in heavier
RA. SCT to locally BKN clouds lower to 2500-3500 feet MSL 00-04Z,
then gradual clearing after 04Z. SCT to locally BKN clouds 2000-3000
feet MSL rebuild for areas within 20 miles of the coast 10-17Z Fri.

Desert Mountain Slopes/Deserts...Clouds based around 5000-8000 feet
MSL over mountains will produce scattered -SHRA and isold (15-20%
chance) TSRA with lower bases and vis briefly in pcpcn this
afternoon through 03Z. Gradual clearing after 03Z.

&&

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

&&

.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...PG
AVIATION/MARINE...CSP