Area Forecast Discussion
Issued by NWS San Diego, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
000
FXUS66 KSGX 240345
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
845 PM PDT Wed May 23 2018

.SYNOPSIS...
A deep trough moving into the region will bring more May Gray and
cooler than average weather through Sunday. There may be areas of
light rain or drizzle in the deep marine at times the next few
mornings. Gusty west winds will continue in the mountains and
deserts, strongest on Friday and Saturday. The trough weakens Sunday
for better clearing, warmer days, and a shallow marine Monday and
Tuesday. Another trough will bring back cooler weather and a deep
marine layer next Wednesday and Thursday.

&&

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

The sky cleared across much of the area today. However, cloudiness
did persist across portions of the San Diego coast. Highs ranged
from the mid 60s at the beaches to the lower 90s in the Colorado
Desert.

Marine layer clouds are developing and spreading back inland this
evening and will reach the foothills overnight with clouds and
fog in the Cajon Pass and the San Gorgonio Pass. There may be
areas of drizzle tomorrow morning.

On Thursday night a trough deepening off the CA coast will bring
back stronger onshore flow and an even deeper marine layer to around
5000 feet. Drizzle is again possible Friday morning. On Friday night
and Saturday, a 500 mb vort max rounding the base of the trough will
deepen the marine layer even further, which may trigger areas of
light rain west of the mountains. Saturday will be the coolest day
with max temps 10-15 degrees below average in the Valleys, Mountains
and Deserts. Skies will be mostly sunny in the deserts and in the
mountains above the marine layer Friday and Saturday, with gusty
westerly winds both days.

Sunday through Wednesday: The trough moves slowly inland Sunday with
weak high pressure aloft bringing warmer days and a shallower marine
layer Monday and Tuesday. But another trough Wednesday through
Friday means that we will end May with Gray and start out June with
Gloom.

&&

.AVIATION...
240330Z...Coast/Valleys/Coastal Mountain Slopes...Low clouds will
continue to advance inland reaching their natural resting point
along the coastal slopes by 12Z. Expect cloud bases between 1500 and
2500 ft MSL with tops near 3000 ft MSL. Areas of dense fog with a
visibility of 1/4 mile or less may occur where the low clouds and
higher terrain along the coastal slopes intersect. Clouds should be
slow to clear again, with some areas potentially not clearing.
Breaks in the cloud deck are possible after 18Z, with SKC-SCT most
likely between 21Z Thursday and 01Z Friday. All of the TAF sites
should see cigs tonight.

Mountain Crests/Desert Mountain Slopes/Deserts...SKC and
unrestricted visibility through 06Z Friday. West/Northwest wind
gusts in the 30-40 mph range may produce localized LLWS,
up/downdrafts and BLDU in the passes after 21Z Thursday. Minor wind
impacts possible at KPSP and KTRM after 00Z Friday.

&&

.MARINE...
West northwest winds with gusts near 20 knots are possible Friday
and Saturday afternoon/evening. Winds will weaken Sunday into early
next week.

&&

.BEACHES...
A long-period south swell will continue to produce elevated surf and
hazardous swimming conditions through Thursday, mainly in Orange and
northern San Diego Counties. Surf will begin subsiding late
Thursday. Sets to 7 ft are possible along southwest facing beaches
Thursday.

&&

.SKYWARN...
Skywarn activation will not be needed today.


&&

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

PZ...NONE.
&&

$$

PUBLIC...Gregoria/Moede
AVIATION/MARINE...Albright



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.