Arnold, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

138
FXUS66 KSTO 052119
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
119 PM PST Thu Feb 5 2026

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.

.KEY MESSAGES...

 - Dry weather with patchy fog in the Valley and lower foothills
   expected through the week

 - Confidence increasing in a pattern change Sunday into next
   week bringing renewed chances for precipitation

&&

.DISCUSSION...

...Today through Saturday...
Current GOES-West visible satellite imagery shows the fog and
stratus from the Valley this morning has lifted and burned off,
with abundant sunshine now being observed on this Thursday
afternoon. The Dense Fog Advisory was cancelled early as
visibilities improved across the region. Patchy dense fog will be
possible tonight into Friday morning, however chances are very
low for any widespread development.

The upper level pattern will feature high pressure over much of
the western US, gradually weakening and shifting eastward as we
head into the weekend. Above normal temperatures will prevail
across interior NorCal, with highs in the 60s to 70s in the Valley
and foothills, and 50s to 70s in the mountains. A weak trough may
bring the potential for light showers over the mountains south of
Interstate 80 on Friday but minimal accumulations or impacts are
expected.

...Sunday and onward...
Confidence is increasing in a pattern change later this weekend
into next week. As the upper level ridge breaks down and shifts
eastward, ensemble guidance indicates that upper level troughing
develops, bringing along the potential for showers, mountain snow,
breezy winds and cooler temperatures Sunday through the middle of
next week. The latest forecast has trended lower for precipitation
and snow amounts, and only minor impacts are expected over this
timeframe. The Climate Prediction Center 8 to 14 day outlook then
favors below normal temperatures and above normal precipitation
for the February 13th through 19th timeframe, indicating the
potential for active weather to continue through at least the
middle of February.

&&

.AVIATION...
Improving conditions for sites within the Sacramento Valley by
this afternoon and evening with sites at VFR conditions after 00z
Fri, outside of MOD and SCK who will remain MVFR to VFR due to
mist. Overnight, we expect visibilities to drop to IFR to LIFR
conditions after 06z from the southern Sacramento Valley southward
as low as quarter-mile with accompanying low clouds with
continued VFR conditions northward and light winds.

&&

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

&&

$$