178
FXUS66 KSTO 281859
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1159 AM PDT Tue Apr 28 2026



.KEY MESSAGES...

 - One more afternoon and evening of mountain showers and
   thunderstorms today. Thunderstorms should be limited to Sierra
   (20-30% chance).

 - Dry weather and warming temperatures through Saturday.

 - Next system possibly late Saturday early next week with low
   confidence at this time.

&&

.DISCUSSION...

...Remainder of Tuesday and evening...
The upper level trough in the area will continue to bring some
lift and instability to the area. Expect scattered showers and
thunderstorms through this evening. Instability isn`t too bad, up
to around 400 J/Kg so some isoalted stronger cells with heavy rain
will be possibly this evening over the Sierra.

This trough moves out of the area tonight with upper level high
pressure building into the area Wednesday through Saturday. This
will bring warm amd mild conditions with high temperatures in the
80s.

Confidence in location and timing of the next system remains.
Ensemble means have been trending to take the upper system more
off shore which would mean less clouds and precipitation. Upper
diffluence and forcing from this system would possibly bring
chance of mountains showers later on Saturday but perhaps as late
as Sunday. Still a fair amount of uncertainity at this time. This
pattern would also put the valley at risk of showers and
thunderstorms depending where it sets up. Stay tuned to updates
but overall this doesn`t appear to be very impactful system either
way.

&&
.AVIATION...

VFR conditions at TAF sites next 24 hours. Light surface winds
generally 10 kts or less. Local MVFR conditions from scattered
mountain showers and isolated thunderstorms this afternoon and
evening until around 03z Wednesday. A few light showers may
develop over the Sierra south of Highway 50 Wednesday afternoon.


&&

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

$$