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000
FXUS66 KSTO 032027
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
127 PM PDT Tue Oct 3 2023

.Synopsis...
Dry and warming conditions this week. Occasional breezy north
wind. The potential for rain and cooler temperatures returns
early next week.

&&

.Discussion...
Eastern Pacific upper level ridging is building in over the
region while upper troughing to the east moves into the Rocky
Mountains. Surface high pressure over the Pacific northwest is
building, strengthening the north-northeast pressure gradient.
this will bring increasing winds this evening and overnight
through Wednesday. Expect breezy north winds for the northern and
central Sacramento Valley with gusts up to 20 to 30 mph. Breezy
northeast to east winds are forecast for the foothills,
especially through canyons and gaps with wind gusts to 30 mph and
locally higher at times. Locally elevated fire weather conditions
are possible with the breezy winds and afternoon humidity
dropping into the upper teens to around 20 percent. Recent rains
will help mitigate fire weather concerns, though, especially for
the mountains and canyons, where 1-3" fell over the weekend.
Lighter north to east winds are expected Thursday and Friday.

Temperatures will trend up this week, more like late summer than
the fall weather we have been seeing. Many Valley locations will
reach 90 degrees or even the low 90`s Wednesday through Friday,
which will be 10 to 15 degrees above normal.

&&

.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)...
The upper-level ridge will be progressing westward and out of our
area Saturday and will be replaced by a troughing pattern
starting Sunday. Heights and temperatures will lower as a frontal
system and short wave trough will approach or area. Current
cluster analysis shows agreement on timing of the frontal system
and shortwave moving into our area. Ensembles (GFS and ECMWF)
depict precipitation entering the northwest counties in our area
late Monday night and into Tuesday. NBM continues to give non-zero
(10-25%) chances of precipitation beginning Monday morning, so
there is some disagreement on precipitation onset timing within
models. Tuesday is currently has the best chances of precipitation
for most of our area, with higher chances in the north-central
Sac Valley, Coastal Range, and Sierra. A 15-25% chance of
precipitation exists for the Delta and Sac Metro on Tuesday as
well.

Temperatures on Saturday will be the warmest, with highs
approaching and breaking 90 for the Valley. Temperatures cool with
the approach and passing of the frontal boundary Sunday through
Tuesday, with highs in the 70s-80s for the Valley and cooler mid
60s for higher elevations.

&&

.AVIATION...VFR conditions are expected over interior NorCal
next 24 hours. Areas of North surface winds up to 15 kts with
local gusts 20-30kts possible near KRDD and KRBL after 02z. &&

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

$$