Challenge, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

882
FXUS66 KSTO 141856
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1156 AM PDT Tue Oct 14 2025

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

.KEY MESSAGES...

 - Cold strong upper storm will continue to bring areas of rain to
   valley from Sacramento southward tonight...ending by early
   Wednesday morning. Additioinal accumlations of up to a half
   inch possible in the valley.

 - Winter Storm Warning continues tonight until 5 AM Wednesday.
   Heaviest snow accumulations of 12 to 18 inches will be possible
   in the Cemtral Sierra with lesser amounts working northward to
   Interstate 80. Heaviest snow accumlations will above 6500 feet.

 - Dry and slight warmup starting Wednesday.

 - Next chance of rain Sunday with a weak system with best chance
   in foothills, north Sac Valley and mountains. Looks low impact
   at this time.

 - Possible north gusty winds Monday.

.DISCUSSION...
Tonight...the strong upper level low that has brought rain and
some snow to the area will continue to linger in the area tonight.
Still looks like a good shot of snow will wrap up on the north
side of this low into the Central Sierra mostly south of
Interstate 80. Snow levels should also drop this evening and
overnight to around 6000 feet with additoinal accumulations of 12
to 18 inches still possible. Been a hard snow forecast as the
first ones are with melting snow and warm ground. As far as rain
in the valley, system looks to continue to wrap around light and
sometimes moderate rain this evening with amounts generally up to
around a half inch additional.

Wednesday...the upper low does pull off to the east. This will put
most of NorCal in dry northerly flow. Temperatures remain cool
genreally in the lower 60s.

Thrusday through Saturday we will be in a short wave ridge
situation which will bring us some pretty mild fall weather in the
70s.

Sunday...pretty good agreement in models that a very progessive
upper wave will push into the PacNW. Winds aloft look to be
somewhat hefty which will bring some gusty winds to higher terrain
but with fire weather not an issue right now impacts should be
little to none. May also be some gusty winds, especially northern
Sacramento Valley Sunday but nothing looking like a wind advisory
at this point but will see how this developes.

Monday...above mentioned PacNW system pulls into across the
norther U.S. and does open up some slight inside slider northerly
flow. This also isn`t looking too impactful but if energy dives
further south could result in stronger north winds...but even with
that seems like it would be below adivsory level. WMR

.AVIATION...
MVFR conditions from precipitation and lower cloud ceilings
expected outside of isolated areas of IFR conditions possible from
snow showers over the Sierra south of I-80 from 19z today until
04z Wed. Snow levels 7000-8000 but lowering back to 5500 to 6500
feet after 21z Tue. Weak southerly winds expected, shifting more
southwesterly after 03z Wed, with gusts up to 10-15 kts over the
northern Sacramento Valley from 21z Tue to 03z Wed. &&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 5 AM PDT Wednesday for West Slope
Northern Sierra Nevada.

&&

$$