589
FXUS66 KSGX 190917
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
217 AM PDT Sun May 19 2024

.SYNOPSIS...
A persistent trough over the West Coast will continue the weather
pattern we have been seeing as of late. Temperatures will remain
slightly below average with gusty winds across the mountains and
deserts. A weak area of low pressure will move across the region
on Monday, which will bring the coolest and windiest conditions
overall. Low clouds will continue nights and mornings, retreating
back to the coast each afternoon.

&&

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

Gusty west winds continue to gust near 25-40 MPH across most
mountain and desert locations early this morning. These winds will
weaken through the morning before returning by the afternoon and
evening hours as a trough hangs over the western part of the
country. Confidence is moderate in seeing winds peak near 40 MPH
across these areas, best chance through mountain passes which may
see winds near 45-50 MPH. Low clouds have filled in much of the
coastal basin this morning with NBM and HREF probabilities
pointing to a fairly good chance in clearing again at the coast by
this afternoon. The deep marine layer will maintain itself
through Monday, so areas of drizzle will be possible west of the
mountains today and tomorrow mornings.

An area of low pressure off the coast to our southwest will combine
with the mean flow and deepen the trough over our region on Monday.
This will further cool the region and increase winds over mountains
and deserts. Confidence increases for these areas to see wind gusts
over 40 MPH and over 55 MPH in wind-prone mountain passes; the San
Gorgonio Pass which has a 70-80% chance of exceeding 55 MPH winds
per latest NBM. Temperatures will be near 5 degrees below average
across the coastal areas with up to 10 degrees below average for
inland areas.

The trough over the West Coast will continue, though not as potent
as Monday. Rising heights will lead to some warmer conditions with
less wind over inland regions. Little day to day weather variations
can be expected from Tuesday through the week, where we will see
slightly below average temperatures and May Gray conditions west
of the mountains in the morning with general clearing toward the
coast by the afternoons. Ensemble cluster model analysis points to
possible weakening of this troughing pattern as a ridge across
Mexico may begin to provide a larger influence over the
southwestern U.S.

&&

.AVIATION...
190850Z...Coast/Valleys... Stratus will continue to fill in across
the valleys with bases 1400-2000 ft MSL and tops to 2700 ft MSL and
higher terrain obscured. Below the cloud deck vis will mostly be
unrestricted. Local -DZ could occur 12Z-16Z. Clearing will occur 16Z-
19Z in the valleys and 18Z-21Z near the coast with some locations
within 5 miles of the coast having BKN CIGs continuing through the
afternoon. Low clouds will spread rapidly inland after 20/01Z
reaching the inland by 09Z. Bases 1500-2000 ft and tops increasing
to around 3000-3500 ft MSL by Monday morning.

Mountains/Deserts... Mostly clear with unrestricted vis through
Monday morning. Areas of W-SW winds with gusts 30-45 kt from the
mountain crests east through the desert slopes and into the deserts
will continue at times through tonight, accompanied by MOD UDDFS and
LLWS over/E of the mtns.

&&

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

&&

.BEACHES...
A series of southwest swells of 2-3 ft at 16-18 seconds from 200-220
degrees will build today and continue through Tuesday, producing
above normal surf of 3-5 ft with locally higher sets on exposed SW
facing beaches, as well as a high risk of rip currents at all
beaches. A Beach Hazards Statement has been issued for today through
Monday evening. Swell and surf will slowly lower Wednesday and
Thursday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...SS