340
FXUS66 KSTO 080845
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1245 AM PST Sun Nov 8 2026
.KEY MESSAGES...
- Dry weather, above normal temperatures, and periodically breezy
winds today through the middle of the week
- Potential shift toward active weather pattern late week into
next weekend; Low confidence persists in the timing of
potential precipitation
&&
.DISCUSSION...
Today-Mid Week:
Warm and dry weather continues as high heights aloft persist over
the next several days. The brief period of ridging aloft is
already transitioning to southwest flow early this morning, which
is then expected to continue into the early week ahead. This minor
pattern shift aloft will usher in slightly cooler, yet still
above normal, high temperatures today and Monday.
Lighter winds will also accompany this shift and despite the more
zonal direction aloft, surface winds look to continue following
offshore and terrain driven trends from the north to east. This
will yield increasing potential for patchy fog development in the
Valley and Delta from Interstate 80 southward both this morning
and Monday morning. Probabilities for visibility less than 1 mile
continue to sit around 40-60% both mornings.
As the upper level pattern begins to see more influence from a
deep trough that has been churning over the Gulf of Alaska over
the last several weeks, an additional period of brief ridging
aloft is expected to build into interior NorCal Tuesday into
Wednesday. Valley winds look to remain largely unchanged but
periodically breezy downslope east-northeast winds along the
Sierra and into the upper foothills do look to develop during this
period. Despite this, current probabilities for wind gusts
greater than 25 mph along the Sierra only sit around 10-30% at
this time. The primary impact of the expected ridging though will
be a return to widespread afternoon high temperatures around 10
degrees above normal on Tuesday and Wednesday. Resultant high
temperatures in the low to mid 70s are forecast for the Valley and
foothills with 60s to low 70s at higher elevations.
Late Week Into Next Weekend:
Ensembles continue to indicate the potential for a shift toward
an active weather pattern, with chances for heavy rain, heavy
mountain snow and breezy winds. However, cluster guidance still
indicates uncertainty regarding the position and timing of the
upcoming trough. The anticipated southward progression of deep
troughing over the Gulf of Alaska toward the California coast
remains the largest piece of uncertainty at this time. With
increasing ensemble consensus for a further southward trajectory
of the initial ejecting shortwave Wednesday-Thursday,
precipitation onset for interior NorCal is now favoring Friday
into next weekend at the earliest. Regardless, the CPC 8-14 Day
Outlook (Nov. 15-21) does continue to highlight a moderate risk
for heavy rain and heavy mountain snow, as well as a slight chance
for high winds which can be anticipated once the pattern does
indeed shift. Be sure to stay up to date with the latest forecast
information and check back for updates as we get closer.
&&
.AVIATION...
VFR conditions are generally expected to prevail at TAF sites
over the next 24 hours, although a 40-60% chance for MVFR/IFR cigs
in FG/BR at Valley and Delta sites is forecast through 16z this
morning. Similar potential for MVFR/IFR cigs in BR/FG possible
after 09z Monday as well. Light winds persist across the forecast
period, remaining less than 12 kts at TAF sites, but still from a
generally north to east direction.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$