National Weather Service

Area Forecast Discussion
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to with any concerns.

Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  
FXUS66 KSTO 210458

955 PM PDT Wed Aug 20 2014

Near to slightly cooler than normal temperatures expected through
the weekend and into early next week. A slight chance of
thunderstorms will be possible over the Sierra Nevada to the south
of Lake Tahoe into early this evening.


Fog product indicates the low clouds have already spread into the
Carquinez Strait area...and with the Ft Ord profiler showing the
marine layer up to around 2600 ft...some stratus should advect/form
in the Srn Sac Vly by morning...or at least become banked-up against
the foothills to the E of SAC. Onshore gradients suggest the Delta
Breeze will weaken overnite...but will increase again Thu afternoon
with little change in temps/thicknesses. The Breeze may not extend
as far N as it did today due to the weaker up-valley flow as the
surface pressure pattern indicates the low center will be farther E
into Ern NV and slightly weaker. Thus...we have updated this evening
to lower the max temps primarily in the valley for the
Marine/Delta influence is expected to maintain cooler than normal
temps over the valley/lower elevations.  JHM

.Previous Discussion...

A trough drops down into the Pacific Northwest and into Northern
California on Friday and shifts to the east over the weekend leaving
Northern California generally in Northwesterly flow aloft between
the ridge over the Eastern Pacific and trough over the Western U.S.
Temperatures will be a little cooler on Friday with highs in the low
80s to low 90s in the Valley and 60s and 70s in the mountains.
Temperatures may be similar to a few degrees warmer on Saturday. No
precipitation is expected Friday into the weekend.


.Extended Discussion (Sunday through Wednesday)

Dry northwesterly flow will remain over the area through the
extended period as high pressure remains off the coast. Expect
benign weather and near normal temperatures to continue through
the early portions of next week.




Mainly VFR conditions the next 24 hours across interior Northern
California. MVFR/IFR ceilings will continue along the western
Delta through Thursday morning, with a slight chance of stratus
moving toward Sacramento TAF sites Thu morning. Isolated
Thunderstorms possible Sierra crest south of Tahoe this afternoon
and evening. South to west winds 10-15 kt except near the delta
southwest winds 15-25 knots. Winds will be diminishing this
evening and tonight.



.STO Watches/Warnings/Advisories...


U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE