393
FXUS66 KSTO 011908
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1208 PM PDT Tue Apr 1 2025

.Discussion...

.Synopsis...
A strong system will continue to impact the region through this
evening bringing moderate to heavy mountain snow, gusty south to
west winds, and scattered showers and thunderstorms. Only light
showers currently expected over the northern Sierra on Wednesday
into Thursday, with dry and warmer weather late in the week and
over the weekend.

.Key Messages...

* Through 11 PM today: Winter Storm Warning for the northern
  Sierra and southern Cascades above 3500 feet. Snow levels 3500
  to 4500 feet today. Snow rates of 1-2 inches per hour through
  mid afternoon. Additional snow amounts of around 1-2 feet.

* Through 5 PM today: Winter Storm Warning for the northern Coast
  Range and Shasta County mountains. Additional snow amounts of 2
  to 8 inches.

* South to west wind gusts up to 20-30 mph today in the Valley and
  foothills, and 30-50 mph over the Sierra Crest; strongest winds
  expected this afternoon.

* 25-45% probability of thunderstorms across interior NorCal
  today. Main threats will be lightning, brief heavy rain, small
  hail, funnel clouds and gusty winds. Best chances are now through
  7 PM PDT.

* Wednesday-Thursday: A very weak system enters the region, with
  just some light showers over the higher elevations of the
  northern Sierra. Little to no impacts are expected.

* Drier and warmer weather returns late week into the weekend with
  periods of breezy north to east winds.

.Changes from previous forecast...

* Thunderstorm potential has increased for today.

&&

.AVIATION...
MVFR/VFR conditions expected through 06z at TAF sites, with
potential IFR/LIFR in scattered SHRA/TSRA today then followed by
primarily VFR after 06z. Widespread IFR/LIFR in SN to persist
along Sierra through 06z, improving to MVFR/IFR after. Snow levels
expected to remain near 3500-4000 feet. Breezy south to west
surface winds through 03z, with strongest gusts to 30 kts through
the Delta, and up to 25 kts through the Valley and foothills.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 5 PM PDT this afternoon for Mountains
Southwestern Shasta County to Western Colusa County-Shasta Lake
Area / Northern Shasta County, and through 11 PM PDT for West
Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.

&&

$$