Area forecast discussion 
National Weather Service San Diego California 
900 am PDT Wednesday may 16 2012 


Synopsis... 
fair weather with some coastal low clouds will continue this coming 
week. A low pressure system will increase the onshore flow Thursday 
and Friday. This will extend coastal clouds inland and produce 
strong winds in the mountains and deserts. Higher pressure returns 
over the weekend through Monday for a modest warming trend and 
less coastal cloudiness...then a little cooler Tuesday and 
Wednesday. 


&& 


Discussion...for extreme southwestern California including Orange... 
San Diego...western Riverside and southwestern San Bernardino 
counties... 


The marine layer was rather anemic this morning with low clouds and 
fog mainly in the San Diego coastal areas. A few patches touched 
Orange County too...but the sun greeted nearly all of US this 
morning. Temperatures will be up today from yesterday thanks to a brief 
high pressure ridge over California. Low clouds will be a little 
more extensive in time and space tonight. On Thursday the ridge 
breaks down as a trough of low pressure will move through California 
Thursday and Friday. This will bring cooler weather especially at 
the coast Thursday and cover all areas Friday. The marine layer will 
get a boost from a coastal eddy tonight and Thursday night...and 
coastal clouds should make it into nearly all the coastal basin 
Thursday night. Strong winds will develop in the mountains and 
deserts Thursday afternoon and continue through Friday afternoon. As 
the trough departs Friday night the marine layer will start to back 
off and coastal clouds will become less extensive. Temperatures will warm 
up through Monday as a high pressure ridge builds a little...weather 
much like today for Sunday and Monday. On Tuesday a northern trough 
moves through the northwest states and that would increase our 
onshore flow again and extend the low clouds. Details will be hard 
to fine tune...but the differences are minor anyway. Fair and 
slightly cooler through the middle of next week. 


&& 


Aviation... 
161530z...coast/valleys...stratus now cleared off the 
coast...returning to the coastal airports between 07-09z tonight 
with bases around 1000-1200 feet mean sea level. The cloud layer will be some 
what deeper tonight due to the development of a coastal eddy yet 
still only extend 5-10 sm inland. Stratus will clear coastal areas 
by 16z Thursday. 


Mtns/deserts...clear with unrestricted visible through Thursday. 


&& 


Sgx watches/warnings/advisories...none. 


&& 


$$ 


Public...mm 
aviation...ts