Area Forecast Discussion
Issued by NWS Sacramento, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

000
FXUS66 KSTO 131014
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
314 AM PDT Fri Oct 13 2017

.SYNOPSIS...
Dry weather continues into early next week. Gusty north winds
will return tonight into Saturday with critical fire weather
conditions expected again. Chance of rain arrives late next week.

&&

.DISCUSSION...
Mostly clear skies prevail across interior Northern California
this morning. Winds have largely dropped off across the region,
with mixing levels dropping as a result. With a more stagnant
boundary layer in place, visibilities near area wildfires are
worse this morning than yesterday as smoke settles down to near
the surface. Temperatures are also rather chilly this morning as
the boundary layer decouples in most Valley locations. As of this
writing, many Valley locales are in the lower to mid 40s.

A frontal system will pass through the Pacific Northwest today,
then drop south into the Great Basin tonight into Saturday. No
precipitation is expected with this system, but gusty north winds
will likely develop behind the front. These winds should start to
pick up tonight, with strongest winds early to mid Saturday. Some
of the wind gusts over higher terrain could reach 40 to 50 mph.
This wind event looks to be a bit stronger than Wednesday`s, but
weaker than the event that started the fires Sun-Mon. A Wind
Advisory and Red Flag Warning has been issued to address these
concerns.

Winds should begin to taper off Saturday night into Sunday as an
upper level ridge over the eastern Pacific builds inland. High
temperatures will rise to a few degrees above normal, but fire
weather concerns diminish a bit with decreasing winds.

Dang

&&
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)



Upper level flow pattern begins to transition in the extended
period as the upper level ridge breaks down and a shortwave trough
pushes through the Pacific northwest states Tuesday. As a result
of the disturbance moving north of the forecast area, temperatures
will drop a few degrees to near normal across northern
California on Tuesday and Wednesday. A larger scale trough and
associated jet stream will approach the region Thursday into next
Friday, which is shaping up to be the first decent chances for a
precipitation event for the forecast area. Temperatures will
decrease a bit more ranging between 5 and 10 degrees below normal
with snow levels dropping to about 6000 feet. Light snow
accumulations are expected at this time with most accumulations
occurring at the highest Sierra peaks with minimal impact to
travel.

&&

.AVIATION...



VFR conditions for the next 24 hours, with the exception of
terminals in northern San Joaquin valley and western portions of
the valley and coastal ridges from smoke related to Santa Rosa
area fires. North winds will increase tonight with gusts in the 30
to 35 kt range for the western valley and Sierra ridgetops.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 PM this evening to 8 AM PDT Sunday for
Carquinez Strait and Delta-Central Sacramento Valley in Glenn,
Colusa, Yuba, Northern Sutter, and Butte County Below 1000 Ft-
Eastern Mendocino NF-Eastern Portion of Shasta/Trinity NF-Lake
County Portion of Lake-Napa-Sonoma Unit-Northern Motherlode From
1000 to 3000 Ft. Includes portions of Nevada-Yuba-Placer-Amador
and ElDorado Units-Northern Sacramento Valley to Southern Tehama
County Line Below 1000 Ft-Northern Sierra Foothills from 1000 to
3000 Ft. Includes portions of Shasta-Trinity and Butte Units-
Northern Sierra Including Lassen NP and Plumas and Lassen NF/S
West of the Sierra Crest (West of Evans Peak-Grizzly Peak-
Beckworth Peak)-Northern Sierra Including the Tahoe and ElDorado
NF/S West of the Sierra Crest-Southeast Edge Shasta-Trinity NF
and Western Portions of Tehama-Glenn Unit-Southern Sacramento
Valley in Yolo-Sacramento Far Western Placer, southern Sutter
and Solano County Below 1000 Ft-Stanislaus NF West of the Sierra
Crest.

Wind Advisory from 11 PM this evening to 5 PM PDT Saturday for
Carquinez Strait and Delta-Central Sacramento Valley-Clear
Lake/Southern Lake County-Northern Sacramento Valley-Southern
Sacramento Valley.

&&

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.