432
FXUS66 KSTO 222113
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
213 PM PDT Tue Apr 22 2025

.Discussion...

.Synopsis...
Unsettled weather and a cooling trend develops tonight and
continues into the weekend with chances for precipitation,
isolated thunderstorms, and breezy winds in the afternoon and
evening hours. Best chances for widespread precipitation,
including rain and mountain snow showers and thunderstorms are
Friday through Saturday, as a colder, stronger system moves
through.

&&

.Key Messages...

* Today-Wednesday: Warm for the rest of today, then trending
  cooler through the rest of the week. Isolated showers and
  thunderstorms tonight, mainly over Shasta County.

-Probability of high temperatures 80 degrees F or higher: 75-100%
     (Today) and 20-50% (Wednesday).

-5-15% chance of isolated showers or thunderstorms Wednesday and
     Thursday PM across northern Sacramento Valley and surrounding
     terrain.

* Thursday-Weekend:

-Cooling trend with breezy to gusty onshore winds Thursday and
     Friday PM

-Isolated to scattered showers and thunderstorms (10-20%)
     possible, primarily from Interstate 80 northward through Thursday,
     becoming widespread Friday afternoon through Saturday

-High elevation snow showers possible late Friday & Saturday, with
     a 65-85% probability of 1 inch or more of snowfall above 5500 feet
     along Sierra/southern Cascades, 25-55% of 4 inches or more

    -Lingering mountain showers Sunday, then trending warmer and drier

.Changes from previous forecast...

* Widespread precipitation chances Friday PM through Saturday

* Isolated thunderstorm potential increasing for Friday PM

* High elevation snowfall potential continues to trend higher
  Friday afternoon through Saturday evening

&&

.AVIATION...
VFR conditions across interior NorCal next 24 hours. South to
west winds expected, with gusts up to 15 to 20 kts for the Central
Valley through 12Z Wed, becoming light through the early morning
hours. &&

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

$$