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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

FXUS66 KSGX 180447 AAA

Area Forecast Discussion
National Weather Service San Diego CA
937 PM PDT Fri May 17 2019

The warming and drying trend will continue into Saturday. The winds 
are also expected to weaken in the mountains and deserts. By late 
Saturday night into Monday another low pressure system will bring 
cooling, gusty winds, and another chance for precipitation. Later on 
Monday and through early Tuesday another brief drying and warming 
period is possible. Late Tuesday through Thursday, a broad trough of 
low pressure over the western states will maintain strong onshore 
flow, cooler than average conditions, and occasional chances for 
precipitation as well over our area. 



Evening Update: No major changes to the forecast this evening. Good 
consensus in the forecast for widespread low qpf rain event Saturday 
night through Monday, with the main precipitation coincident with 
the front moving through Sunday. Strong wind potential Monday 
through Tuesday.

Previous Short Term Discussion: A rather low latitude jet will 
continue to push Pacific frontal systems with precipitation into the 
west coast at times. 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, look consistent with 
the continued parade of frontal systems moving through at least into 
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. 


180255Z...Coast/Valleys...Low clouds over the mountains will push 
into the SD/RIV/SBD County valleys after 04Z Saturday, most 
widespread in SD/RIV County valleys. These will push westward toward 
coastal TAF sites after 08Z, though coverage not as widespread and 
long lasting. Medium to high confidence of VFR/MVFR conditions 
expected with bases 2000-2500 ft MSL. Scatter out should occur after 
16Z Saturday. 

Mountains/Deserts...West winds with gusts 20-25 kts will continue 
through 08Z Saturday. Some SCT cumulus over the mountains this 
evening, clearing as the evening progresses. VFR conditions through 
the day on Saturday with winds expected to pick up again in the 


A Small Craft Advisory is in effect through 11 PM Friday evening for 
strong westerly winds with gusts to 25 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.



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.