047
FXUS66 KSTO 271733
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
Issued by National Weather Service Hanford CA
1033 AM PDT Tue Oct 27 2026
&&
.KEY MESSAGES...
1) Cool and mostly dry weather conditions through Friday.
2) Breezy southwest winds through today over the Sierra.
3) Pattern change may bring unsettled weather conditions this
weekend.
&&
...SHORT TERM DISCUSSION...
Time for your favorite part of the day, reading the Area Forecast
Discussion (with some sarcasm)! Latest visible satellite imagery
depicts low clouds over portions of the Sacramento Valley this
morning, while high clouds stream southeast across the region. A
weak shortwave trough will traverse the area today, bringing a
slight chance of water falling from the sky over Shasta County
this afternoon. Otherwise, mostly dry conditions and below normal
high temperatures are expected. Afternoon highs are expected to be
in the 60s for the Valley, 50s-60s for the Foothills, and 40s-50s
over the mountains. Breezy southwest winds over the Sierra will
continue to decrease throughout the day, aka the chances you get
swept away today decrease into the afternoon. Overnight lows will
be slightly cooler, generally in the low to mid 40s across the
Valley, 30s to 40s in the Foothills and in the 20s over the
mountains. Wowza, perfect short sleeves weather! Make sure to pump
that AC overnight!
Lighter onshore flow is expected Tuesday, with a transition to a
brief period of northern flow Wednesday morning. A surface high
will build briefly across the forecast area Wednesday, promoting
drier and near-seasonal temperatures prevailing until the weekend.
Forecast high temperatures are expected to warm up into the 70s
for the Valleys on Wednesday, before a gradual cool down Thursday
and Friday. Cold morning lows are expected for the mountains and
higher elevation basins the next few days, with near to below
freezing temperatures. Patchy fog or haze will be possible each
morning in the Valley. Keep those eyes peeled people!
...LONG TERM DISCUSSION...
And so it continues. Here is where things may get feisty (grab
that popcorn fellas)! Spooky day (Halloween), may scare some trick
or treaters with some H2O instead of candy (how cruel!). The
Foothills and Sierras in Tuolumne, Calaveras, Amador, Alpine, and
El Dorado counties all have the highest chances for H2O falling
from the sky. The 75th percentile shows lighter amounts less than
half an inch mainly in the Sierra, while the 90th percentile shows
amounts ranging from 0.5 to 1 inch Halloween evening. Though, the
higher chances look to be focused on Sunday. Models tend to agree
that the higher rain chances will occur on the eastern side of
the forecast area. While the 10th and 25th percentiles each show 0
inches respectively, the 75th ranges from 0.5 to 1 inch in these
counties, and the 90th percentile shows 1 to 2 inches. The models
have the higher end of these amounts centered around Tuolumne
County, and decreasing in amounts moving Northward along the
Sierra. The Foothills have a 90th percentile of 0.4-0.8 inches of
rain throughout Sunday. As for the Valley, 90th percentiles
between 0.1 to 0.25 inches are displayed. That was aloooottt of
percentiles!
Lingering showers may be possible through Monday morning, but
models indicate a ridge building in right after the trough exits
by Tuesday. Through next week, there is a lot of uncertainty in
cluster analysis as to prevailing weather conditions. Some models
show another trough moving in Wednesday, while others show a zonal
to slight ridging pattern through end of next week. We shall see
what verifies, but for now it remains confuzzling.
&&
.AVIATION...
Primarily VFR conditions everywhere for the next 24 hours. Winds
less than 12kts everywhere through 16z Wednesday, then
periodically gusty winds up to 20kts in the valley, mountain and
foothill canyons until 22z Wednesday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Public/Aviation....Moore
