Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 241025

Area Forecast Discussion
National Weather Service Sacramento CA
325 AM PDT Sun Sep 24 2017

Warmer through mid week with dry conditions continuing. Breezy
north winds next few days for increased fire danger. Cooler
towards the end of the week with lighter winds.


Northern California under upper northerly flow between building
high pressure over the eastern Pacific and a closed low over the
southern Great Basin. Combination of surface high pressure over
the Pacific northwest and upper north flow will bring continued
breezy north winds. These winds and warming airmass will keep
daytime RH values on the low side with only poor to moderate RH
recovery at night. Wind and RH will bring periods of critical fire
weather through early next week. Upper ridge will edge slowly
inland over the next couple of days bringing a few to several
degrees of airmass warming each day. Upper ridge axis is forecast
to center over the west coast by Wednesday which should bring
lighter pressure gradients and lighter winds with maximum
temperatures leveling off at a few degrees above normal.


Eastern Pacific ridging will remain over the area dry and warm through
the week. Daytime highs will likely remain 5-10 degrees above
normal, with low 90s across the Valley, Delta and into the lower
foothills. By the end of the forecast period, the ridge will
slowly be displaced as a trough approaches the Pacific Northwest.
A portion of that upper energy could extend into our area and keep
temperatures from trending upward and potentially bring slight
cooling. Overall, little change in weather is expected. EK



VFR conditions expected for Valley TAF sites for the next 24
hours. Northerly gusts up to 20-25 kts possible in the northern
Sacramento Valley today 18-02z.


Red Flag Warning from 5 PM this afternoon to 5 AM PDT Tuesday
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 Motherlode From 1000 to 3000 Ft. Includes portions of
Calaveras-Tuolumne 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.


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