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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

FXUS66 KSGX 250348

Area Forecast Discussion
National Weather Service San Diego CA
845 PM PDT Sun Mar 24 2019

Warming will continue through Monday under weak high pressure aloft. 
High clouds will thicken Tuesday ahead of a Pacific trough that will 
move inland across the state Wednesday and Thursday. It will bring 
breezy, cooler weather and a chance for light showers. The weather 
looks dry with seasonal temperatures next weekend. 



Highs today were some 5-11 degrees higher than yesterday in the 
valley, mountain and desert zones today. The biggest temperature 
increase was at Julian with an 11 degree jump from 53 Saturday to 64 
today. Warming at the coast was, well, not so much. It was limited 
to 1 degree at the San Diego Airport, 2 degrees at Carlsbad, and 3 
degrees at Newport Beach. The hot spot in our area was 86F at the 
aptly named city of Thermal. The hot spot in the nation was at Rio 
Grande Village, Texas, with a high of 94F. 

The warming in the coastal and valley zones will peak on Monday when 
the apex of the ridge drifts overhead. On Tuesday it will turn a 
little cooler west of the mountains as the ridge slides east, the 
onshore flow increases, and the marine layer deepens. In contrast, 
the lower deserts, sheltered from the cooler airmass, will actually 
be warmer on Tuesday than on Monday. 

Looking ahead to the midweek Pacific trough, the 18Z GFS and the 12Z 
ECMWF project most its energy impacting central California with only 
a glancing blow down here in SoCal. Wednesday will be a breezy, 
cooler day with a chance at a few light showers through Wednesday 
night over and west of the mountains. Thursday will also be breezy 
and cool, but most likely dry behind the departing trough. 

*From Previous Forecast*

The global operational models (CMC/GFS/ECMWF) continue to  handle 
the subsequent pattern across the West into next weekend quite 
differently. The GFS digs additional energy sharply, while the 
ECMWF does not, allowing heights to rise over the SW for much 
warmer weather. The CMC also shows more digging, but farther 
east. The GFS also suggests moderate (cool) Santa Ana winds are 
possible on Sunday, but due to the pattern uncertainty, that has 
been left out of the picture. For now, we have used a blend of temp 
guidance for next weekend. All models keep the weather dry for this 


250300Z...Coast...CLR skies expected tonight at KSNA and coastal 
Orange County with VFR conditions prevailing. There is a small 
potential for stratus development at KCRQ/KSAN, mainly 05-10Z, but 
any cigs are expected to be patchy with frequent alternations 
between SCT-BKN likely. Bases will range between 600-900 ft AGL at 
KCRQ, and 800-1200 ft MSL at KSAN. OCNL periods of vis 3-5 SM, 
locally below,  on obscured coastal slopes/mesas overnight. VFR 
conditions at all terminals after 15Z tomorrow with clear skies 
prevailing through early Tuesday AM, with low clouds expected to 
redevelop thereafter. 

Valleys/Mountains/Deserts...Mostly clear skies with unrestricted vis 
through tomorrow night. 


No hazardous marine weather is expected through Friday.


Locally elevated surf this evening will continue to subside over the 
coming hours. Otherwise, no surf-related concerns on the horizon.


Skywarn activation will not be needed Monday.