American Falls, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

782
FXUS65 KPIH 221145
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
445 AM MST Mon Dec 22 2025

.KEY MESSAGES...

- High elevation snowfall event through today. Winter Storm
  Warnings and Winter Weather Advisories remain in effect for
  some areas.

- Weather pattern remains active through Christmas week.

- Continued well above normal temperatures through Christmas.
  Slight cooling but still above normal next weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 253 AM MST Mon Dec 22 2025

Moist W-SW flow off the Pacific continues to support rain and snow
over large portions of southeast Idaho early this morning. Snow
levels have been rising, and have cancelled the Winter Weather
Advisory for the Wood River Foothills/southern Wood River Valley
with all rain now falling there. Snow is mixing with rain in some of
our other advisory/warning areas as well. Areas of precipitation
will generally continue today, lifting northward tonight into
Tuesday morning as winds shift more into the SW with low pressure
amplifying off the California coast. Snow levels will generally run
as high as 8,000 feet across the southern highlands to as low as
6,500 feet at times up over the Central Mountains. Expect high
temperatures to reach the 40s and low 50s today.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 116 PM MST Sun Dec 21 2025

We are still looking at a band of rain and snow to lift northwest
out of our are Tuesday as another low helps reload the pattern
to our west. For Christmas Eve day and night, we see a quick but
potentially healthy shot of rain and snow across central and
eastern Idaho. With strong southerly flow into our area, we are
looking at fairly strong upslope into places like the Wood River
Valley, Arco, Monida Pass, and Island Park. Meanwhile,
downslope is likely along and south of the Snake River into the
Teton Valley. We did knock down the precipitation amounts a bit
as it appears the numbers might be influenced by some
unrealistic amounts coming from the GFS. The latest
precipitation amounts are in the 0.30-0.70" range where the bulk
of the moisture falls. Places like the Challis and Pahsimeroi
Valleys are looking at a major shadow effect and closer to 0.10"
or less. Higher elevations are looking at upwards of 1" in
favored areas. There are a few pockets of 1.0-1.25" currently in
the forecast, which is somewhat backed up by probability
forecasts that have a 20-40% chance of more than 1.0". If you
took the GFS at face value, we COULD have another 0.20-0.50"
across the area. Do expect these numbers to change as we get
closer, but just beware that this time period could be another
wet and impacted travel period for us. The ECMWF is a bit slower
than other models, and actually holds on to heavier
precipitation especially across the central mountains for
Christmas. The rest of the model numbers point to keeping some
showers around but nothing too crazy amount-wise. Our Blend of
Models is NOT following the ECMWF`s plan at the moment. The
latest trends in the extended models and Blend of Models is to
dry things out by the end of the extended holiday weekend. The
GFS, earlier run of the ECMWF and Blend of Models close a low
off well to our southwest over the weekend and pulls all of the
moisture out of Idaho. Temperatures through Christmas remain
well above average, with cooler temperatures returning as early
as Friday. Even then, the current forecast has highs at or just
above average.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 445 AM MST Mon Dec 22 2025

Areas of rain and showers continue today, with little consensus in
model guidance on declaring any organized breaks at this time.
Precip type should stay rain from this point forward, which will
help keep vsbys up. Have started timing out an end to the precip
this evening into tonight as the moisture flow shifts north of
southeast Idaho. Overall VFR conditions are expected, but drops into
MVFR will be possible, with KSUN and KDIJ the best candidates. Cigs
so far early this morning have been a bit higher/better compared to
NBM guidance...will be interesting to see if this continues or
things nudge down here over the next several hours. Our cig forecast
runs somewhere in between current obs and the NBM.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 AM MST this morning for
IDZ060-064-066.
Winter Storm Warning until 11 AM MST this morning for
IDZ071>074.

&&

$$

SHORT TERM...01
LONG TERM...Keyes
AVIATION...01