180
FXUS66 KSTO 072058
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1258 PM PST Fri Feb 7 2025

.SYNOPSIS...
Cold weather and breezy winds expected through this weekend. More
active weather returns mid to late next week bringing renewed
chances for rain, mountain snow, and gusty winds.

&&

.DISCUSSION...
Drier weather has returned this afternoon, and is expected to
continue through early next week. The main stories of the forecast
through Monday are cold early morning temperatures, as well as a
period of breezy winds on Sunday. Valley lows will be near or
below freezing through Monday morning, with temperatures in the
20s to low 30s in the foothills, and single digits to teens in the
mountains. The NBM currently has a 30 to 65% chance of below
freezing temperatures in the Valley across Saturday, Sunday, and
Monday, with even higher chances on Saturday and Monday in the
northern Sacramento Valley (70 to 95%). Be sure to take steps now
to protect pets, plants, pipes, and people!

Overnight Saturday into Sunday, and continuing into Monday
morning, we`ll also be seeing breezy northerly winds. Strongest
winds will start late Sunday morning and taper off in the evening.
The NBM currently has 30 to 65% chance of winds gusting to 35 mph
or higher, primarily along the western side of the Sacramento
Valley. Otherwise, the weather will be clear and dry through
Monday.

&&

.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...
Ensemble guidance continues to show strong agreement in the
general progression of the upper level pattern mid to late next
week. A retrograding trough looks to back build from the
Intermountain West toward the West Coast moving into Tuesday while
a gradually deepening shortwave approaches the Gulf of Alaska.
This will allow below normal high temperatures and cold morning
temperatures to continue through Wednesday morning, with some
potential for breezy to gusty northerly winds on Tuesday. The Gulf
of Alaska shortwave is then expected to rapidly progress toward
the Pacific Northwest/northern California by Wednesday, bringing a
return to active weather across the mid to late week period.
Given persistent and deeply entrenched cold air across interior
NorCal ahead of the midweek system, there is at least some
conditional potential for low elevation snowfall into portions of
the northern Sacramento Valley and toward Sierra foothills
locations as well.

The primary uncertainty regarding lower elevation snowfall with
this system is largely centered around the timing of attendant
warm air and moisture advection into the region. As of right now,
best chances for this overlap of advecting moisture and near
freezing temperatures at lower elevations would be overnight
Wednesday into Thursday morning. While a high degree of
uncertainty still precludes this forecast, some 15 to 30 percent
probabilities of snowfall up to 2 inches are indicated for the
Redding and Shasta Lake areas at this time, with similar
probabilities into the Nevada City and Pollock Pines areas as
well. Despite that specific uncertainty, periods of moderate to
heavy rain and mountain snow are expected elsewhere as this system
moves through. Current probabilities of exceeding 1 foot of
snowfall above 5000 feet sit around 40 to 60 percent, likely
resulting in additional mountain travel impacts. Gusty southerly
winds are also in play on Thursday as the trough progresses. Given
high uncertainty, be sure to monitor the forecast into next week
as details become clearer.

&&

.AVIATION...
Conditions improving to generally VFR across interior NorCal next
24 hours, although scattered MVFR possible along the Sierra
through 00z in lingering snow showers. Light southerly winds less
than 12 kts today shifting to northerly overnight. 5 to 15 percent
chance of MVFR in BR 10z-16z Sacramento southward.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$