000
FXUS66 KSTO 032202
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
202 PM PST Thu Dec 3 2020

.SYNOPSIS...
Persistent dry weather will continue, above average high
temperatures and cool nights. Gusty winds are possible Sunday and
Monday which could lead to elevated fire weather concerns.

&&

.DISCUSSION...
The weather today is not much different from previous days across
interior Northern California as the area mostly remains under
persistent high pressure. A weak, dry weather system is currently
moving over far northern California today, producing a few upper
level clouds across the region. Otherwise, temperatures today are
expected to be similar to yesterday with Valley locations in the
mid to upper 60s and 40s to 60s in the mountains and foothills. Upper
level ridging builds more over the area tomorrow as the weak
trough moves out, allowing daytime temperatures to rise a few
more degrees.

Ensemble guidance continues to indicate a weather system moving
through the PacNW and far northern California Saturday.
Discrepancies remain between the models and runs on how far south
the weather system will move into NorCal. For the most part,
models are keeping precipitation north and west of the forecast
area, though there is a chance the Coastal Range and Shasta
County may receive light precipitation. For the rest of the area,
the only impact from this system will be slightly lower
temperatures, cloud cover, and a brief increase in humidity.

As the weather system moves to the east on Sunday, ensembles
indicate it will form into a closed low then digging south
throughout Sunday into Monday. Significant model differences
exist in the location of this low with the GEFS having it form
over northern Nevada and the ENS having it form over the northern
border of California and Nevada. Overall, this pattern is likely
to bring gusty north to east winds to interior Northern
California Sunday and Monday. The strength of the winds is still
uncertain depending on the final track of the low. The GEFS
solution would bring gustier winds than the ENS. Daytime relative
humidity is forecast to decrease with these winds, as well. Taking
into account the lower RH and continued extremely dry vegetation,
gusty winds could create elevated fire weather concerns during
this period. -HEC

&&

.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
Gusty winds are currently forecast to continue into Monday, as
described above, as a cut off low moves south across the western
US Monday into early Tuesday. The cut off low is then expected to
remain near the Baja coast Tuesday through most of the week with
ridging forming over Northern California. Not much change in
temperature is expected with daytime temperatures around 5 to 15
degrees above normal and cool overnight temperatures creating
frosty mornings. Dry weather will prevail through late next week.
-HEC

&&

.AVIATION...
VFR conditions are generally expected to prevail across the
Sacramento Valley over the next 24 hours. Periods of MVFR
visibilities are likely in the northern San Joaquin Valley near
Stockton and Modesto as a result of haze. Winds are forecast to
remain below 10 kt at the terminals.

&&

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

&&

$$