614
FXUS65 KPIH 032321
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
421 PM MST Wed Dec 3 2025

.KEY MESSAGES...

- Winter storm watch in effect for eastern mountain and valley
  zones Thursday night through Friday night. Heavy snow and
  strong winds likely with highly impacted travel.

- Widespread snow likely all locations Thursday night and Friday
  morning. Turning warmer Friday with many lower elevations
  below 5500 feet turning to rain.

- Windy to very windy conditions develop in the Snake River
  plain and on mountain ridges starting Friday and continuing
  through Sunday afternoon.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 200 PM MST Wed Dec 3 2025

Main impact will be significant Pacific moisture moving into
southeast Idaho late Thursday through Saturday. A winter storm
watch has been issued for the eastern and southeastern zones
both mountain and valley locations. Current probabilities have a
90 percent chance of greater than 2 inches in valley locations
in watch areas and above 6 inches above 7 thousand feet and a
10 percent chance of over 6 inches an valley locations and above
a foot in higher elevations. The Sawtooths and Sun Valley and
central mountain locations not expected to get as heavy a
snowfall but above 7 thousand feet 4 to 9 inches still possible
with up to 2 inches in the Snake River Plain Thursday night and
Friday morning. Expected to see significant warming Friday and
that could cut snowfall amounts significantly if it occurs
faster than expected in the far eastern mountains. Wind speeds
15 to 25 mph with gusts up to 35 mph will be widespread Friday
and Friday night which could cause extensive blowing snow in the
watch areas as well. Lows tonight teens and 20s with patchy fog
expected once again in valleys and especially parts of the Snake
River Plain. Highs Thursday again 20s mountains and 30s valleys.
Lows Thursday night mainly 20s into lower 30s low elevations and
highs Friday mainly 30s mountains and mid 30s to lower 40s
valleys. Much milder conditions Friday night with lows 20s to
lower 30s mountains and 30s valleys.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 200 PM MST Wed Dec 3 2025

The extended portion of the forecast remains active into the
weekend and early next week, especially across the higher terrain.
Upper level flow aloft will remain active bringing surges of
moisture through the region off and on that will allow for daily
PoPs to remain in the forecast for much of next week. Still a bit of
uncertainty though where the deepest moisture will ultimately reside
over this period. What does seem a bit more certain is the
seasonally mild airmass that will be in place across the area with
daytime highs likely in the 40s and maybe even 50s across the Magic
Valley and Snake Plain, especially as we get into the upcoming work
week. Most of the precip throughout the period will be focused
across the eastern highlands however and these areas will likely
remain just cold enough to keep at least a rain/snow mix in the
forecast during the daylight hours with snow expected during the
overnight periods with some light accumulations expected into the
middle of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 420 PM MST Wed Dec 3 2025

Main problem tonight is low clouds and potential fog.
Satellite trends and high res models show low clouds advecting up
the Snake Plain. Seeing clouds breaking up at BYI and expect that to
continue through the night. Webcams verify obs at SUN that show just
a few low clouds which should dissipate after sunset and/or once the
downvalley wind kicks in. Main trouble spot will be IDA where IFR
and perhaps LIFR visibilities and ceilings are likely. At PIH,
conditions could clear for a brief time this evening but will most
likely cloud back in overnight. Winds may stay up just enough at
both locations to keep observations from completely tanking. Expect
DIJ to see VLIFR conditions this evening with light winds likely
supporting those conditions. DIJ may see conditions improve
overnight once the widespread stratus arrives.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Thursday afternoon through late Friday
night for IDZ058>066.

&&

$$

SHORT TERM...GK
LONG TERM...McKaughan
AVIATION...13