Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 190933
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
233 AM PDT Thu Apr 19 2018

.SYNOPSIS...
A trough of low pressure will generate strong west winds in the
mountains and deserts through tonight. There is also a chance of
light precip along and west of the mountains through this evening.
High pressure will bring a warming trend and ligher winds for the
weekend. Slight cooling next week as a trough develops off the
west coast.

&&

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

Winds are increasing across the mountains and deserts this
morning. The highest wind gusts recorded so far have been 52 mph
at Whitewater in the San Gorgonio Pass, and 43 mph at Volcan
Mountain. Winds will continue to strengthen through mid-morning,
especially along the mountain crests and desert mountain slopes.
Isolated strong winds are possible in the low deserts where any
mountain waves surface. Winds will weaken but become more
widespread in the deserts during the afternoon. Gusts will
generally be around 40-55 mph with isolated gusts to 60 mph.

The compact cold front and small band of precipitation is
currently making its way into Santa Barbara County. This frontal
precipitation is forecast to fall apart before even making it to
Ventura County. Whatever is left of it will arrive in Orange/San
Diego County by mid-morning. Recent runs of the high resolution
models have backed off on precipitation amounts - not that there
was a lot to begin with. Some areas along and west of the
mountains may pick up a few hundredths of an inch, mainly in San
Diego County. Aside from the wind and showers, this trough will
bring much cooler weather. High temps will be anywhere from 10 to
20 degrees below normal today.

The trough will depart tonight, with lighter winds following.
Gradual warming takes place through Sunday as weak high pressure
moves in behind the trough. High temperatures will climb to around
5 to 10 degrees above normal. There may be some patchy low clouds
and fog along the coast Saturday and Sunday mornings.

Slight cooling will occur early next week as weak trough develops
along the west coast. Model solutions really begin to diverge
around Tuesday with regards to the track of the aforementioned
trough. Best bet is for the cooling trend to continue, more
widespread marine layer clouds each night and morning, and gusty
west winds in the mountains and deserts each afternoon.


&&

.AVIATION...
190900Z...Coast/Valleys...Mostly broken low clouds with bases 2000-
3500 feet msl will continue this morning but scatter out from
northwest to southeast from 15-20Z. Isolated -shra mainly in San
Diego County between 16-20Z. Mainly scattered clouds this afternoon.
Areas of low clouds after 03Z this evening, between about 2000-2500
feet msl.

Mountains/Deserts...Areas of coastal slope and ridge obscurations
will occur through about 19Z mainly in San Diego County, mostly
below 7000 feet MSL due to clouds and fog. Isolated -shra with local
-shsn will occur, mainly 16-20Z in San Diego County. Areas of strong
winds will continue, strongest this afternoon and evening from the
mountain crests through the desert slopes and into the deserts. West
winds 20-30 knots local gusts 40-45 knots. Areas of reduced vis
below 3sm in blowing dust and sand are probable in deserts this
afternoon and evening.

&&

.MARINE...
Winds and choppy seas will peak this afternoon and evening, mainly
in the outer waters, presenting a hazard for small craft. No
additional hazardous marine weather is forecast Friday through
Monday.


&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning until 2 AM PDT Friday for Coachella Valley-
     Riverside County Mountains-San Diego County Deserts-San
     Diego County Mountains-San Gorgonio Pass Near Banning.

     Wind Advisory until 11 PM PDT this evening for Apple and Lucerne
     Valleys-San Bernardino County Mountains.

PZ...Small Craft Advisory until 2 AM PDT Friday for Coastal Waters
     from San Mateo Point to the Mexican Border and out to 30 nm-
     Waters from San Mateo point to the Mexican Border Extending
     30 to 60 nm out including San Clemente Island.

&&

$$

PUBLIC...SS
AVIATION/MARINE...MM


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