Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 280615

1015 PM PST Sat Dec 27 2014

Mainly dry weather will continue for the next few days, with
north winds and frosty overnight lows. Stronger north winds and a
few mountain showers may be possible for early/middle next week.



Strong short wave moving SEwd into the Pac NW will push moisture Swd
over the CWA overnite. This moisture is spilling over or moving
through the Ern Pac/W Coast ridge. Any precip from the short wave
will be light and limited to areas NW-NE of our CWA. These clouds
should clear the Nrn portion of the CWA early Sun morning...and then
by afternoon over the Srn portion of the CWA.

In general...the HR3 shows mainly MVFR vsbys in the valley through
15z Sun...with isolated patches of lower vsby. Lighter Nly flow has
allowed dewpoints and thus humidities to recover allowing for a
little more fog than last nite. With the higher dewpoints...mins may
be higher in many locales than last nite as well...and frost will be
more limited.

Cold and breezy/windy wx expected as energy from the Arctic Circle
drops Swd into Norcal phasing with/reinforcing the Pac NW short wave
as it drops Swd into Norcal late Mon/Tue. This will bring mtn snow
showers...breezy/windy conditions...and the coldest air of the
season through the end of the year (a -2 to -3 anomaly over the Nrn
Rockys and portions of the Pac NW depending on the standard pressure
chart of interest.) In looks like the ol` Polar Vortex
will ring out the Old Year and ring in the New Year over a large
portion of the CONUS.      JHM

.Previous Discussion...

High temperatures are not expected to vary much the next few
days, with lower to mid 50s expected for the Valley and 30s to
40s for the mountains. These forecast highs are within a few
degrees of normal.

A shortwave trough moves out of western Canada and into NorCal
late Monday into Tuesday with breezy to strong northerly winds
Monday night through Tuesday night. The drier trough may still
bring a slight chance of light showers Monday night into Tuesday
over the Sierra/Cascades and generally southward of I-80 in the
Valley. Snow levels will be roughly 2000-3000 ft with only a few
inches of snowfall expected above approx 2500 ft.



.Extended Discussion (Wednesday through Saturday)

Extended models continue to show a high amplitude ridge persisting
near the west coast. For Wednesday, the main concern will be the
continuation of breezy & gusty north to east winds in our region.
The pressure gradient will remain tight between the high pressure
ridge and a low pressure storm sliding southward along the eastern
edge of the high. Lighter winds by Thursday. The colder air moving
into our region from Canada will keep daytime highs below normal
for Wed & Thurs while overnight lows get quite chilly with frosty
early morning temperatures. Temperatures will slightly warm for
Fri & Sat as the ridge axis moves closer to our region. Slight
hint of another storm wave nudging into NorCal over the weekend,
but confidence is low since models are not in good agreement. JBB



VFR conditions expected tonight except for areas of MVFR fog
developing in portions of the Southern Sacramento and Northern San
Joaquin valley with local IFR/LIFR conditions possible at KSMF,
KSAC, KMHR, KSCK, KMOD until 18z Sun. Light winds.


.STO Watches/Warnings/Advisories...

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