Area Forecast Discussion
Issued by NWS San Diego, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 29 30 31

000
FXUS66 KSGX 102042
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
142 PM PDT Sat Jun 10 2023

.SYNOPSIS...
Cooler temperatures, gusty onshore winds and periods of showers are
expected this weekend. The most widespread shower activity will
occur late tonight through Sunday morning, becoming more confined
to the mountains Sunday afternoon. Isolated thunderstorms may be
possible over the mountains tonight and on Sunday. Unseasonably
cold this weekend, with highs topping out 15-25 degrees below
normal across inland areas on Sunday. Warmer for next week, with a
shallower marine layer.

&&

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

At 1 PM, low clouds continue to blanket the coastal basin and
increasing high clouds are moving in ahead of a low pressure
system. Today will be another cool day across the region as highs
top out 5-15 degrees below average, with the greatest departure in
the valleys and mountains. Much cooler conditions are expected on
Sunday as highs will range as much as 15-25 degrees below normal
for areas away from the coast.

Cloud cover is expected to be persistent for the coast today,
though some breaks in the low clouds are possible for the
valleys; high clouds will continue to stream overhead for all
areas. Breezy onshore winds will occur this afternoon, and again
Sunday afternoon, over the mountains and the desert slopes, with
peak gusts topping out near 35-50 mph.

The parent low pressure system, which is located off the coast of
Point Conception this afternoon, will maintain its strength as it
continues its southeastward path today and tonight. PVA will kick
into Southern California today leading to the onset of scattered
showers from the coast to the mountains this evening. Rainfall is
generally expected to be light with most locations seeing less
than 0.20". Some instability will be present across our northern
mountains into the High Desert tonight into Sunday morning, with
CAPE values reaching several hundred J/kg on Sunday. This could
lead to isolated thunderstorms across this area, where rain rates
could reach 0.25"/hr. Scattered showers will persist through
Sunday morning across the coast and valleys, with activity mainly
remaining confined to the mountains by the afternoon and evening.
Instability diminishes by Sunday evening, with just some lingering
light showers from the deep marine layer Sunday night into Monday
morning.

For next week, ensemble guidance is in agreement with a closed low
forming to our southwest and a weak ridge building to the east
over the Four Corner region or the Southern Plains. This will
support slow, but steady, warming each day through the end of the
work week. The 12z ECMWF Eps continues to suggest negative (but
weakening) height anomalies over Southern California so while
highs will be warmer, they are still expected to be slightly below
normal for this time of the year. At least there will be more
sunshine, especially late in the week, when the marine layer is
much shallower.

&&

.AVIATION...
102030Z...Coast/Valleys...BKN-OVC clouds with bases 1500-2500 ft MSL
and tops to 4000 ft MSL will continue partial clearing in the Inland
Empire but remain in other areas through this afternoon with local
terrain obscurations. BKN-OVC clouds 1000-2500 ft MSL and tops to
6000 ft MSL will be widespread after 03Z Sun, continuing through the
day Sun, along with areas of DZ/-RA and terrain obscurations,
especially 03Z-17Z Sun. Local vis 2-4 miles will occur 03Z-17Z Sun
in BR/DZ/-RA.

Mountains/Deserts...Occasional SCT-BKN clouds at/above 20000 ft MSL
will continue through this evening, with SCT-BKN clouds at/above
10000 ft MSL late tonight and Sun. Areas of terrain below 6000 ft
MSL will be obscured in clouds on the coastal slopes late tonight
and Sun. SCT SHRA and ISOLD TSRA will develop late tonight and
continue Sun mainly in the mountains and high deserts. est winds 15-
25 kt with gusts 30-45 kt will develop after 22Z, continuing through
Sun with MOD UDDFS.

&&

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

&&

.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...EA
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.