007
FXUS66 KSGX 060417
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
917 PM PDT Sun May 5 2024

.SYNOPSIS...
Chilly overnight temperatures tonight into Monday morning, with lows
5 to 10 degrees, locally up to 15 degrees in the deserts, below
normal. Gradually warming conditions expected through mid-week.
Periods of breezy westerly winds expected in the afternoons and
evenings in the mountains and deserts early this week, with the
potential for offshore winds Wednesday. Warmer and dry conditions
are expected into next weekend.

&&

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

Satellite imagery at 9 PM is showing mostly clear skies, with some
clouds against the coastal slopes of the mountains. Winds have died
down, with only a few gusts 35-40 mph below the San Gorgonio Pass
and in the High Desert. Winds will continue to weaken through
midnight into early Monday. A peak wind gust summary and rainfall
totals have been headlined on our weather.gov/sandiego homepage.

Chilly conditions expected overnight by May`s standards. Lows Monday
morning could be up to 15 degrees below average for this time of
year in the deserts. There is a 20% chance lows in portions of the
High Desert will fall to the mid-30s. Winds are expected to weaken
but not completely diminish in the High Desert which will be a
limiting factor in how cold it gets there overnight. Daytime
temperatures will rebound under mostly sunny skies Monday. Highs
temperatures are expected to be 3 to 10 degrees warmer than Sunday
for the coast and valleys; 15 to 20 degrees warmer than Sunday in
the mountains and High Desert; and 4 to 12 degrees warmer than
Sunday in the lower deserts. That translates to highs in the mid
to upper 60s along the coast, low to mid-70s for the valleys and
High Desert, mid-80s for the low desert, and mid-50s to 60s for
the mountains.

From the previous discussion issued at 2 PM May 5...

Southern California will remain under weak cyclonic flow through at
least Wednesday as a ridge builds near the Pacific Northwest and a
strong upper low is centered over the central US. Warmer
temperatures are expected on Monday, with more gradual warming
occurring on Tuesday and Wednesday. Breezy onshore west to northwest
winds will develop each afternoon and evening over the mountains and
deserts, with peak gusts approaching 40 mph.

For the second half of the week, ensemble guidance is pointing
towards a positively-tilted shortwave breaking off from the parent
low over the central US, and retrograding towards the Desert
Southwest. A period of offshore winds are expected on Wednesday as
this low strengthens, but will turn predominantly back onshore for
Thursday and Friday as the low becomes centered near the Four
Corners region. Otherwise, little day-to-day change is expected
temperature wise Wednesday through Friday, with highs remaining
within a few degrees of seasonal averages. Marine layer low clouds
will continue for the coastal areas and portions of the valleys each
night and morning, potentially deepening and spreading further
inland by next weekend.

&&

.AVIATION...
060400Z...Coasts/Valleys/Foothills...Patchy low clouds will occur
through 16Z Mon with bases 2500-4000 ft MSL and most prevalent near
the foothills. Most vis will remain above 5 miles. Mostly clear
skies will prevail after 16Z Mon, continuing through Mon evening
with unrestricted VIS.

Mountains/Deserts...Areas of gradually decreasing W/NW winds with
gusts 25-40 knots will continue through 11Z Mon with MOD UDDFS.
Local terrain obscurations will occur below 5500 ft MSL on the
coastal mountain slopes through 09Z Mon in decreasing clouds.
Otherwise, mostly clear skies with unrestricted VIS will prevail
through Mon evening.

&&

.MARINE...
West to northwest winds will gradually diminish overnight, with some
gusts to 25 knots in the outer coastal waters (30-60 NM from the
coast) until around or shortly after midnight. West to northwest
winds will gust to around 20 knots Monday and Tuesday afternoon and
evening.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 10 PM PDT this evening for Coastal
     Waters from San Mateo Point to the Mexican Border and out
     to 30 nm.

     Small Craft Advisory until 3 AM PDT Monday for Waters from San
     Mateo Point to the Mexican Border Extending 30 to 60 nm out
     including San Clemente Island.


&&

$$

PUBLIC...CO/EA
AVIATION/MARINE...Maxwell