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000 
FXUS66 KSGX 212043
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
143 PM PDT Thu Mar 21 2019

.SYNOPSIS...
Showers will continue across the region this afternoon, and taper
off tonight. Friday will be dry and a little warmer, then another
low pressure system moving inland through northern and central 
California will bring stronger and gusty southwest to west winds 
in the mountains and deserts on Saturday with a small chances for 
light showers along and west of the mountains. Sunday through 
Tuesday will be dry with a warming trend with the next chance for 
precipitation around Wednesday of next week. 

&&

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

At 1 PM, water vapor satellite displayed an upper-level low 
centered over southern Nevada. Radar showed a band of mostly 
light showers moving southeast across the region, just now 
entering San Diego County. Additional rainfall through this 
evening looks to be lighter than expected, with an additional one-
quarter inch of precipitation possible, and an inch or two of 
snowfall expected, mostly above 6500 feet. The Winter Weather 
Advisory for the Riverside and San Bernardino County Mountains 
continues through 8 PM this evening. 

Weak ridging will develop Friday, with dry weather and highs 5-10
degrees below normal. A trough will then move across northern CA
on Saturday. Lack of upper-level dynamics and moisture will limit
shower activity over our area, with only small chances of light
precip over and west of the mountains. 

Upper-level heights build early next week, with southwesterly flow
aloft and dry weather across southern CA. Highs will be mostly
near normal Sunday through Tuesday, with Monday and Tuesday being
the warmest days.

On Wednesday and Thursday, models show an upper-level trough
moving across the western states with continuing differences in 
the details. The GFS is dry over southern CA, while the ECMWF
generate precip. The current forecast uses a blend, with 
increasing chances for precipitation centered around Wednesday.
Snow levels will range from 5000-6000 ft through the period. As 
the trough moves inland, there will also be periods of stronger 
and gusty southwest to west winds in the mountains and deserts.

&&

.AVIATION... 
212030Z...Coasts/Valleys...Variable SCT-BKN clouds with bases 
2000- 4000 ft MSL will continue through the period. Areas of RA 
will affect the terminals through 03Z, with vis reduced to 3 SM 
during heavier showers. 

Mountains/Deserts...SCT -SHRA in mountains through this evening with 
low clouds occasionally obscuring slopes. West SFC winds 15-20 kts 
gusting to 35 kts over mountain crests, desert mountain slopes, and 
through the passes today. MOD UDDFTS likely over and east of the 
mtns at times. -SHRA unlikely to make it to KPSP/KTRM, with SCT 
clouds bases around 7000 FT MSL.

&&

.MARINE...
A few isolated showers today, with no hazardous marine weather or 
seas expected through Tuesday. 

&&

.BEACHES...
Continued long period west swell will generate elevated to high surf 
at the beaches through Friday morning, particularly in San Diego 
County. See the High Surf Advisory for more information. Large swell 
rebuilds over the weekend, potentially bringing another round of 
high surf.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory until 8 PM PDT this evening for 
     Riverside County Mountains-San Bernardino County Mountains.

     High Surf Advisory until 1 PM PDT Friday for Orange County 
     Coastal Areas-San Diego County Coastal Areas.

PZ...NONE.
&&

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