355
FXUS66 KSTO 280749
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1249 AM PDT Fri Mar 28 2025

.Discussion...

.Synopsis...
Active weather continues today through Saturday morning. A brief
lull in the activity for most of the day on Saturday. The next
weather system will arrive on Sunday-Tuesday AM, then a very short
"break" in widespread activity. Then, late Tuesday morning a more
robust and stronger system is forecast to move into the area.
Still a fair amount of discrepancies amongst ensembles regarding
the potential impacts/precipitation totals on storm 3 (Tuesday -
Friday morning).

.Key Messages...

* Winter Weather Advisory elevations above 5500 feet
  Sierra/Southern Cascades. Periods of moderate mountain snow
  through Friday Evening. 24-hour Probability of snowfall > 6
  inches: 40 to 60 percent.

* Slight chance (20%) of Isolated Afternoon/Evening Thunderstorms
  Today. A 15% chance of t-storms in the afternoon/evening on
  Sunday, mainly in the foothills and mountains.

* Brief lull Saturday followed by a return to active weather
  Sunday into next week with two more periods of at least light to
  moderate rain/mountain snow expected with gusty winds and
  isolated thunderstorms possible.

* Sunday-Tuesday AM System: Snow levels 4500-5500 feet. 48-hour
  Probability of snowfall > 8 inches: 60 to 90 percent above 5500
  feet along Sierra/southern Cascades. Overnight forecast runs
  have lowered snow levels slightly...very early Tuesday morning
  snow levels could reach 3000 feet for a short period.

* Tuesday-Friday AM: Wettest of this series of storms with
  rainfall generally 0.50" to 1.25" rain in Valley, locally higher
  rain totals in Shasta County, with snow accumulations possibly
  more than a foot. Low forecast confidence with this system.

.Changes from previous forecast...

* No changes to any potential impacts. Slight fluctuations in rain
  and snow totals for Sunday - Tuesday AM storm system.

&&

.AVIATION...

VFR conditions expected to prevail next 24 hours at TAF sites,
although some brief periods of MVFR possible through 00z in -SHRA.
MVFR/IFR expected along Sierra in light/moderate snow showers
through 06z as well. Steady snow levels around 4000 to 5000 feet,
fall to 3000 to 4000 feet after 00z. South to west winds gusting
20 to 30 kts north of Interstate 80 through 15z, with breezy winds
gusting 15 to 20 kts region wide to follow.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 PM PDT this afternoon for West
Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.

&&

$$