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Area Forecast Discussion (AFD)

Issued by San Diego, CA (SGX)

FXUS66 KSGX 112143

Area Forecast Discussion
National Weather Service San Diego CA
143 PM PST Tue Dec 11 2018

Mid and high clouds have moved to the east this afternoon. 
Decreasing clouds with weak offshore flow developing on Wednesday,
however daytime temperatures west of the mountains will remain in
the sixties to low seventies. High pressure aloft and weak 
offshore flow will bring warming west of the mountains for 
Thursday with locally gusty northeast winds near the coastal 
slopes of the mountains. A little cooler for Friday as onshore 
flow returns, then a little warmer for next weekend under weak 
high pressure aloft.



Today through Thursday... A weak upper level low pressure system 
centered over the California bight this morning continues to move 
toward the southeast. The subtropical moisture being advected 
northward in the form of mid and high clouds has been displaced
eastward this afternoon. A few low clouds linger over the coastal
areas and inland valleys. Patchy low clouds and fog will likely
return to areas west of the mtns and could increase in coverage
late tonight.

High temperatures through Wednesday will vary only slightly from 
those of Monday.

For Thursday, building high pressure aloft along the West Coast 
and surface high pressure over the Great Basin and central Rockies
will bring warming west of the mountains and gusty east to 
northeast winds near the coastal slopes of the mountains and below
passes and canyons.

Friday through Monday... A trough of low pressure moving inland 
along the West Coast on Friday will bring a return of onshore flow
with cooling for coastal and valley areas. The return of onshore 
flow will also bring a return of patchy coastal low clouds and fog
for Friday night into Saturday morning. High temperatures will 
increase by a few degrees for Saturday and Sunday with weaker 
onshore flow and with weak high pressure aloft moving inland 
through the western states.

For Sunday night into Monday, a weak low pressure system in the
southern stream of the westerlies may amplify somewhere in the
vicinity of the southwest states. If it amplifies a little to the
west of southern California, it could bring some light
precipitation to portions of southern California. It it amplifies
to the east, the passage through southern California would be
mostly dry. This brackets the range of global model solutions for
early next week in the vicinity of the southwest states with no
clear model preference yet to emerge. The most recent runs of the
deterministic medium-range models continue to disagree
significantly on the potential for precip next Tuesday. The GFS
favors a wet solution and the European model favors a dry


112000Z...Generally clear skies and unrestricted visiblities, then 
around 12/06Z this evening areas of BKN low clouds based around 800-
1600 feet MSL and vis reduced to 3-5SM. Tops around 2000 feet MSL.


No hazardous marine weather is expected through Saturday. 


Surf will create a high rip current risk today. Surf up to 6 feet is 
forecast, mainly in southern San Diego County, before subsiding 
tonight and Wednesday.


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