Strong Wind in California, May 12, 2018

Area Forecast Discussion
National Weather Service San Diego CA
138 PM PDT Sat May 12 2018

.SYNOPSIS...
Low pressure centered over the Great Basin will move little through
early next week as it slowly weakens. Another will follow for the
middle of next week, maintaining onshore flow, periods of marine
clouds, gusty winds over the mountains and deserts, and below
average high temperatures into next weekend.

&&

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

The marine clouds were hanging tough over the coastal basin and well
up onto the coastal slopes at Noon PDT. Based on gage reports
through 1 PM PDT, most of the light precip had ended. Storm totals
have been posted and headlined on our web site. Surface pressure
gradients were holding around 7 MBS onshore, maintaining peak wind
gusts 20 to 30 MPH in windy spots with max values 40 to 50 MPH
through the desert passes.

Clouds will likely hold for the remainder of the day west of the mts
with just a few breaks here and there. The eddy will weaken, but the
marine clouds will persist and possibly thicken. Some patchy drizzle
is not out of the question, especially on the slopes, but should not
amount to much.

A cut-off low pressure center is parked over the Great Basin today
and will slowly spin and weaken through Tuesday, maintaining onshore
flow, a deep marine layer, and cool weather. Some patchy, drizzle
could develop, especially over the higher terrain due to the depth
of the moist layer, but should not be as extensive as last night.
The marine layer may shrink a bit Tue/Wed as the low, and onshore
flow weakens.

Another Pacific trough will approach on Tuesday and swing east
across the State and into the Great Basin Wed/Thu. This reinforces
the cool, onshore pattern, deepens the marine layer again, and
creates another round of gusty westerly winds over the mts/deserts.
This system is not forecast to cut-off, so should remain more
progressive, allowing modest warming inland Fri or Sat.

Any warming will be fleeting though, as the models show yet another
shortwave amplifying SE into SoCal after next weekend, maintaining
the cool, onshore Spring pattern. Aside from mid next week period,
daytime temperatures will range from 5 to 15 degrees below average.

&&

.AVIATION...
122025Z...Coast/Valleys/Coastal Mountain Slopes...Low clouds with
SCT-BKN layers 1500-3500 ft MSL and tops to 6000 ft MSL will
continue through this evening. Higher terrain will be obscured in
clouds/fog with vis 1-3 miles at times. Low clouds becoming SCT-BKN
again Sunday morning after 12Z.

Desert Mountain Slopes/Deserts...Mostly clear skies with
unrestricted vis through Sunday. Areas of west winds gusting 20-25
kt at times will continue this afternoon.

&&

.MARINE...
No hazardous marine weather conditions are expected through
Wednesday.

&&

.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...10
AVIATION/MARINE...PG