240
FXUS65 KPIH 121006
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
306 AM MST Wed Feb 12 2025

.SHORT TERM...Today through Fri Night. A quickly evolving pattern
will bring all sorts of significant winter weather through
central and eastern Idaho. First, both this morning and Thu
morning, expect bitter cold temperatures accompanied by some wind
that will push apparent temperatures (similar to wind chill
temperatures) to 20 below zero and colder both days, with some
apparent temperatures colder than 30 below in the Beaverhead-Lemhi
highlands this morning. Stronger northeast wind/flow tonight and
Thu morning will bring the arctic air feeling into the Shoshone-
Lava Beds area. Both days will have the northern end of the Snake
River plain also suffering through this bitter cold. To top it
off, there are clouds around that could produce some flurries and
light snow this morning in southern portions of the forecast area,
and possibly into the early afternoon. Accumulations will be
negligible.

Late Thu morning, it will feel as though some cosmic being threw a
switch. A strong, warm, and moist winter storm will push into
central and eastern Idaho from the southwest. This is an
atmospheric river event of massive proportions. Except for the
north central portion of the forecast area, where the Wood River
basin will absorb most of the punishment, all other areas are
under a Winter Storm Watch. Just for the Thu afternoon to Fri
evening period, locations even in the Snake River plain/eastern
Magic Valley have solid potential to reach a foot of snow,
although amounts right now appear to be more in the 3 to 7 inch
range for the 50-50 break line. Amounts are even bigger in the
more mountainous areas to the east and south. The Wood River Basin
will also be struck with heavy snow, on the order of 4 inches in
the lower elevations like Carey to up to 20 inches on ridges. The
mild temperatures in this incoming airmass will strongly warm Thu
afternoon highs by 10 to 15 degrees. This means some rain at the
lower elevations that could reduce the snowpack, but it will still
be significant and by far the heaviest snow of this winter (so
far). Even in the north central mountains that border Lemhi
county, snowfall will be impactful, but at this time it appears as
though the Lost River Range and the Challis/Pahsimeroi region will
reach only Winter Weather Advisory levels.

Gusts to 35 mph will also add to the hazards, with blowing and
drifting snow challenging snow control efforts.

.LONG TERM...Sat through Tue night. Moderate to heavy snow
continues Sat for the eastern half of the forecast area, with
lighter snowfall in the west. Rain and snow continue on Sat night
and Sun, and a second storm is likely for Sun night and Mon.
However, these storms continue the warming trend and will likely
be rainy at elevations below 6500ft elevation. Continued elevated
wind through the period.

Messick

&&

.AVIATION...12/12Z through 13/12Z. Low stratus and fog meandering
around the Snake River plain may impact KIDA and KPIH, but
expectations are that marginal VFR should be maintained at least.
Bitter cold temperatures KIDA and KPIH may be more problematic for
airdrome operations. KBYI, KSUN, and KDIJ should have unlimited
CIGs and VSBYs.

Messick

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Extreme Cold Warning from 9 PM this evening to 10 AM MST
Thursday for IDZ051>053.

Winter Storm Watch from Thursday morning through Friday
afternoon for IDZ051>068-073>075.

Extreme Cold Warning until 10 AM MST this morning for IDZ052-053-
067.

Winter Weather Advisory from 11 AM Thursday to 5 PM MST Friday
for IDZ069>072.

&&

$$