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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

FXUS66 KSGX 171652

Area Forecast Discussion
National Weather Service San Diego CA
922 AM PDT Fri May 17 2019

A warming and drying trend is expected to begin today that will 
extend into Saturday. The winds are also expected to weaken in the 
mountains and deserts today.  Another low pressure system will bring 
cooling, gusty winds, and another chance for precipitation to 
develop late Saturday night into early Monday. Later on Monday and 
through early Tuesday there will be another drying and warming 
period. Late Tuesday through Thursday, a persistent trough of low 
pressure over the southern plateau will maintain cooler than average 
conditions with occasional chances for precipitation as well over 
our area. 



.SHORT TERM (Today through Sunday)...
A rather low latitude jet will continue to push Pacific frontal 
systems with precipitation into the west coast at times. One such 
system is moving out this morning with a moist boundary layer around 
5000 feet deep, and the pattern will transition to weak ridging and 
warming over the southwest into Saturday. This should last only a 
brief time period as by late Saturday into Sunday another storm 
system is expected. This will bring another round of cooling, and 
strong, gusty west winds in the mountains and deserts. Some mostly 
light precipiation along and west of the mountains late Saturday 
into Sunday night is expected with the cold front as it moving 
across southwestern California.


.LONG TERM (Monday through Thursday)...
The models, including the ensembles and WRF, are all on board with 
the continued parade of frontal systems moving through into at least 
early next week. Monday will be a day of waning showers followed by 
drying and warming. The next Pacific low pressure system may arrive 
some time around Tuesday bringing more cooling, gusty winds, and 
another chance for precipitation to move in. A trough of low 
pressure will linger in the vicinity of the southwest states for the 
middle part of next week maintaining cooler than average 
conditions and additional chances for precipitation to develop. 


171500Z...Coast/Valleys...SCT-BKN clouds with bases 3000-4000 ft MSL 
through 17Z with most areas clearing thereafter. Low clouds will 
redevelop after 06Z with bases 2000-2500 ft MSL. Cigs will be most 
persistent in San Diego County, with coverage expected to be more 
patchy in Orange County and the Inland Empire. Clearing should occur 
near 16Z Saturday. 

Mountains/Deserts...Winds are expected to increase after 18Z with 
west winds gusts of 20-25 kt expected and MOD UDDFS possible. Winds 
will decrease after 03Z Saturday. Some SCT cumulus over the 
mountains this evening.  


A Small Craft Advisory is in effect through 11 PM Friday evening for 
strong westerly winds with gusts 25-30 kts. Brisk winds Saturday 
afternoon will gust over 20 kts. Winds will increase again Sunday 
through Monday with hazardous boating conditions possible.


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


CA...Wind Advisory until 11 AM PDT this morning for Apple and Lucerne 
     Valleys-Coachella Valley-Riverside County Mountains-San 
     Bernardino County Mountains-San Diego County Deserts-San 
     Diego County Mountains-San Gorgonio Pass Near Banning.

PZ...Small Craft Advisory until 11 PM PDT this evening 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.