862
FXUS66 KSTO 131910
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1210 PM PDT Mon Apr 13 2026
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.KEY MESSAGES...
- Isolated mountain shower/thunderstorm chances today, then dry
through Wednesday morning.
- Quick moving system Wednesday-Thursday brings light mountain
rain/snow alongside gusty north winds in the Valley.
- Warmer and drier weather expected late week into the weekend
followed by additional precipitation chances Sunday into early
next week.
&&
.DISCUSSION...
...Today - Tuesday...
Lingering mountain shower and isolated thunderstorm chances
continue through this evening as the system that brought
widespread precipitation impacts to the region through the weekend
departs. While additional precipitation totals will remain light,
thunderstorm chances sit around 5-15% through tonight, with
highest potential across the mountains/foothills south of Highway
50. Dry weather is expected to prevail elsewhere today, with
Tuesday remaining dry area wide as well. With weakening winds and
clearing skies overnight some 30-50% probabilities exist for
patchy Valley fog development on Tuesday morning.
...Midweek...
Moving into Wednesday, a quick moving system looks to introduce
light mountain rain and snow shower chances by Wednesday morning.
Current NBM probabilities of rainfall greater than 0.25" sit
around 30-50%, with highest chances across the Sierra/southern
Cascades and the Shasta County terrain. Snow levels are expected
to remain around 6000 feet through Wednesday evening when the bulk
of the precipitation is anticipated. As dry weather continues at
lower elevations through this event, increasing north to east
winds are looking likely as the system departs on Thursday. Wind
gusts 25 to 35 mph are generally expected throughout the Valley,
although NBM probabilities of gusts up to 40 mph around 20-40% do
exist for the northern and central Sacramento Valley on Thursday.
...Late Week into the Weekend...
As the midweek system continues to eject eastward through the end
of the week, breezy north winds are likely to persist on Friday
before trending lighter by the weekend. Dry weather is expected to
persist on Friday and Saturday as a brief period of ridging aloft
builds in over the weekend. This will allow temperatures to
return to near to above normal through the first half of the
weekend. Ensemble guidance does indicate additional periods of
active weather as another deepening trough arrives Sunday into
early next week. While exact details remain variable at this time,
rain/mountain snow, isolated thunderstorm chances, and breezy to
gusty onshore winds will all be possible given the current
forecast trajectory of the system. At the moment, the trough does
look more progressive and quick moving relative to the system that
brought widespread, prolonged impacts last week and through the
weekend.
&&
.AVIATION...
General VFR conditions are expected over the next 24 hours. Areas
of MVFR/IFR/LIFR conditions are possible in the Valley tomorrow
between 10-18Z Tuesday morning due to low clouds and patchy FG/BR.
Currently there is a 30 to 50% chance of visibilities less than
1/2 mile in the Central Sacramento Valley tomorrow morning.
Chances for isolated showers and thunderstorms continue today
over the mountains which may result in areas of MVFR/IFR
conditions between 21Z and 06Z. Winds may be erratic with
direction and speed in and around thunderstorm activity.
Surface winds will be generally 12kts or less, with periodic
northwest gusts 15 to 20 kts in the northern San Joaquin Valley
and Delta between 22Z and 04Z today.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
