Chester, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

421
FXUS66 KSTO 101951
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1251 PM PDT Tue Jun 10 2025

.DISCUSSION...

.SYNOPSIS...
Isolated shower/thunderstorm chances over Shasta County terrain
continue today as a progressive shortwave ejects eastward late
today. Broad zonal flow is then expected to set up across interior
NorCal through the remainder of the week, until troughing arrives
by the weekend. As a result, an overall stagnating weather
pattern of predominantly dry weather, near normal temperatures,
and breezy onshore flow looks to persist.

&&

.KEY MESSAGES...

* Today:

 -Comparatively cooler temperatures today, although areas of
  Moderate HeatRisk persist.

 --Probability of Valley High Temperatures > 95F:
  ---Northern/Central Sacramento Valley: 60-90%
  ---Delta, S. Sacramento Valley, N. San Joaquin Valley: 20-50%

 -Breezy onshore flow, strongest in the Delta and vicinity during
  the afternoons and evenings.

 -Chances for isolated afternoon/early evening showers and
  thunderstorms:
    --Today: 10-20%, across Shasta County mountains and northern
     Coast Range

* Wednesday-Next Monday:

 -Gradual cooling trend expected through the remainder of the
  week. Primarily Minor HeatRisk as temperatures become more
  seasonable.

 -Probability of Valley High Temperatures > 90F:
  --Northern/Central Sacramento Valley: 60-90% Wed-Thu, 30-60%
   Fri-Mon
  --Delta, S. Sacramento Valley, N. San Joaquin Valley: 50-80%
   Wed-Thu, 20-40% Fri-Mon

 -Onshore flow expected to persist with periods of breezy winds,
  mainly in the afternoons and evenings and strongest across the
  Delta and vicinity.

 -Continued ensemble uncertainty persists regarding a trough
  digging southward from the Gulf of Alaska by the weekend.
  Current trends indicate a continuation of seasonable, dry, and
  breezy weather at this time.

.Changes from previous forecast...
 -No notable forecast changes since last update.

&&

.AVIATION...
VFR conditions expected at Valley TAF sites next 24 hours, with
possible MVFR/IFR conditions over Shasta County due to isolated
showers and thunderstorms from around 00z today through 04z
Wednesday. Mostly onshore flow in the Valley/Delta, with surface
winds at or below 12 knots. Period of gustier surface winds from
around 20z through 12z Wednesday, with surface gusts up to 25
knots possible.

&&

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

$$