646
FXUS66 KSGX 211731
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
931 AM PST Fri Feb 21 2025

.SYNOPSIS...
Santa Ana winds will be more localized to passes and foothills
today as a thin marine layer hugs the coast with low clouds this
morning. Warm weather will continue into the weekend, with
further warming by early next week as high pressure anchors over
the region. An area of low pressure is expected to move closer to
SoCal by later next week, bringing cooler weather with an increased
chance of precipitation.

&&

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

Update: Low clouds and patchy fog continue to scatter out as weak
offshore winds are beginning to influence the area. Latest vis
satellite imagery also reveals further erosion of the marine layer
over the inner coastal waters. For the higher elevations, currently
there are some stronger wind gusts out of the ENE peaking at around
30 mph so far, and these will continue to increase with gusts
approaching 45 to 50 mph by later in the day. This downsloping wind
will help to warm up the inland valleys into the lower 80s today.
There will be a return of the marine layer again tonight, although
this should remain mostly confined to the coastal areas again.

There is little change with the model data, which still displays a
strong ridge building in over the area this weekend into next week,
with much warmer temperatures, with Wednesday still looking to be
the warmest day. Models are still relatively consistent with the cut-
off U/L developing and moving over the region going into the early
part of next weekend, which will not only bring a relief to the warm
temperatures, but will also provide a chance of some rain. The
timing and track of this feature is still somewhat uncertain.

(Previous discussion submitted at 306 AM)

Light southerly winds near the coast are helping to bring in
marine air and enhance low cloud development this morning. Cloud
bases are higher than those of yesterday, so fog is more confined
to higher coastal terrain. HREF / NBM models begin to clear low
clouds out of the coastal areas by later this morning. This is
occurring as offshore flow keeps these clouds closer to the sea,
where inland areas are seeing N/E wind gusts 10-25+ MPH. Winds
will be weaker today than yesterday with passes seeing the highest
winds near 45 MPH at times. Mountain and desert regions will see
similar weather today vs. yesterday, but further warming will
take place west of the mountains with many locations reaching into
the upper 70s and lower 80s.

Pressure heights aloft will increase, leading to a more stabilized
atmosphere. This will bring less of a marine layer influence near
the coastal areas with further warming to all areas by Sunday. Low
to mid 80s will occur from the lower deserts to the western
valleys and Inland Empire. Mountains areas into the high desert
will see highs in the 60s and 70s. High pressure to our south will
bloom into a 591 DM high by early next week, leading to the peak
of the heat. By Tuesday and Wednesday, we can expect high
temperatures near 5 to 10 degrees above average will be seen at
the coast with highs near 15 to 20 degrees above average inland as
a thermal ridge dominates the southwestern part of the country.
Confidence is growing that Palm Springs will see their first day
in the 90s this year starting as early as Monday, best chance by
Tuesday and Wednesday. Chances are low to moderate of seeing 90
degree temperatures west of the mountains by this time, but would
not be surprised to see a warmer forecast in the coming days. Even
though it is February, make sure to take it easy in the heat as
it`s been awhile for all of us!

Ensemble models are in agreement of an area of low pressure moving
off the coast into our vicinity by later next week. Confidence on
this forming and bringing cooler weather to the area is moderate
at this time. Details on the exact path of the weather system and
if it will give us any precipitation is still inconclusive,
though model ensembles start to show a wetter pattern as we enter
the month of March.

&&

.AVIATION...
211045Z...
Coast...Low clouds currently based at 500-800ft MSL have
filled in along the coast and up to 10 mi inland this morning. These
bases will likely (50-70% chance) gradually lower as the morning
progresses, falling to 300-600 ft MSL by 12-15z. VIS restrictions
are currently down to 3-5 SM for inland areas but down to 0-2 SM
where clouds are intersecting the higher terrain. If the bases do
fall to 300-600ft MSL, VIS restrictions to 3-5 SM are expected along
the immediate coast (including KSAN and KSNA), with 0-3 SM for the
inland areas and coastal mesas (including KCRQ). Low clouds
retreating offshore 14-17z. Very patchy low clouds look to redevelop
along parts of the immediate coast after 06z Saturday. If they do,
CIGs would be near 200-500ft MSL with associated VIS restrictions 2-
4 SM along the coasts and 0-2 SM for the coastal mesas.

Valleys/Mountains/Deserts...VFR conditions prevail through Saturday
morning. North-northeast to easterly winds over
mountains/foothills/deserts and parts of the Inland Empire
(generally areas below/south of the Cajon Pass), remaining
intermittently gusty through this evening. Gusts to 20-30 kts and
mod up/downdrafts near and over mountains.

&&

.MARINE...
No hazardous marine conditions are anticipated through Saturday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

UPDATE...Stewey
PUBLIC...APR
AVIATION/MARINE...KW