782
FXUS65 KPIH 081958
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1258 PM MST Mon Dec 8 2025

.KEY MESSAGES...

- Above average temperatures expected throughout the week

- Rain and higher elevation snow likely, with most impacts above
  pass level

- Breezy/windy conditions will persist through at least midweek

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 1257 PM MST Mon Dec 8 2025

Northwest flow will impact our weather to start out the week,
bringing plenty of moisture some higher ridges and passes. This
pattern is abnormally warm, so snow levels will be on the rise.
Look for those to peak tomorrow afternoon around 7000-8000ft
over most of eastern Idaho, although they may end up about
1000ft lower from Island Park down through the southeast corner.
Some colder air TRIES to drop over the Divide tomorrow afternoon
and evening, but never really gets a chance to do it. We will
likely see snow levels dip around Island Park, Dubois and into
the Challis area into the 5500-6500ft range, before shooting up
to above pass level tomorrow night...except around Island Park
where a bit of colder air is trapped. With this being a
northwest flow pattern, a huge chunk of the precipitation will
fall across the Sawtooths and Frank Church, Island Park, Tetons
and Big Holes. We will occasionally see some better moisture
"pivot" into the southeast highlands in the mountains and
highest elevations for the South Hills and Albion Mountains.
Most of the Snake Plain and Magic Valley will dry, with an
occasional surge of light precipitation mainly for higher bench
areas. The biggest impact across the Plain will be stronger
winds. Winds ramp up tonight and stay strong, save for a brief
lull tomorrow afternoon. Sustained winds of 15-30 mph with gusts
of 25-45 mph (location dependent). We COULD push barely into
WIND ADVISORY territory across the INL and Arco Desert, but
certainly nothing worth issuing a headline for at the moment.
For those areas favored the heaviest precipitation, 48 hour
totals through sunrise Wednesday, 0.50-1.0" totals are likely.
Higher elevations of the Sawtooths and surrounding ranges look
to exceed 1.50". There is a 20-40% chance of exceeding 1.0" for
the Big Holes and Tetons, but those amounts may be inflated due
to higher resolution models being too aggressive sometimes in
these patterns. There is a 30-60% chance of more than 1.50" for
the Sawtooths/surrounding ranges, and a 15-25% of exceeding
2"...but we may be seeing similar over-aggressive forecasting
there as well. In terms of snowfall numbers, areas above 9000ft
in those favored moisture areas...we are looking at potentially
8-18" with localized higher amounts. Much lighter amounts, up to
5", are possible down to near 7000ft. Due to that colder air
dipping into Island Park, we could see 1-4" for lower
elevations. Circling back to the wind, gusts at times of 35-45
mph are expected at ridgetop. That could cause some blowing and
drifting conditions in spots, but again that is well up in
elevation and only impacting backcountry activities. Based on
all of this, we don`t expect any headlines right now for snow or
wind.

We are going to start a period of above average temperatures,
including lows. Overnight temperatures stay above freezing
except for middle elevation valleys and the mountains.
Valley highs push well into the 40s and even low 50s Tuesday,
with only spots remaining below freezing closer to ridgetop
level. It will be even warmer Tuesday night where the wind will
keep things "mixed out", with overnight temperatures in the mid
30s to mid 40s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 1257 PM MST Mon Dec 8 2025

Extremely mild conditions is the main talking point in the long term
period with temperatures ranging in the 15 to 20 degrees above
normal range Wednesday through next Monday.  At this point for the
next 8 days there appears to be no intrusion of cold air on the
horizon.  Will have lingering showers Wednesday with the retreating
atmospheric river conditions sliding north as upper ridge begins to
build to west.  Precipitation mainly limited to the Sawtooths,
central mountains and eastern highlands.  Snow levels between 8 and
9 thousand feet so not expecting snow impacts by Wednesday.  It will
be windy with 20 to 30 mph sustained winds in the Snake River Plain.
 Highs Wednesday mainly 40s mountains and 50s to near 60 valleys.
Thursday through next Monday generally much drier with only some
mountain showers with high temperatures remaining very warm with
mainly 40s mountains and mid 40s to mid 50s valleys.  By Friday
expect to see a significant decrease in wind speeds as well.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1025 AM MST Mon Dec 8 2025

Main impact will be at DIJ where high chances of rain overnight
along with lower MVFR to IFR ceilings are likely. Elsewhere
expect wind impacts at PIH, IDA and BYI with sustained 15 to 25
knot speeds through Tuesday morning with gusts 25 to 35 knots
expected. Just have vicinity showers at SUN and kept ceilings
VFR but under 50 percent chance of showers and MVFR ceilings
overnight and Tuesday as well.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Keyes
LONG TERM...GK
AVIATION...GK