287
FXUS65 KPIH 060928
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
228 AM MST Sat Dec 6 2025

.KEY MESSAGES...

- Winter storm wraps up this morning, Winter Storm Watches and
  Advisories extended another 6 hours.

- Light rain and snow picks up again Sunday afternoon for many
  locations. Precipitation threat continues each period through
  at least Thursday.

- Windy to very windy conditions should peak today in the Snake
  River plain/eastern Magic Valley/southern hills and subside by
  evening.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 159 AM MST Sat Dec 6 2025

Still quite a bit of reflectivity showing up on radars to the
west, so have extended the Warnings and Advisories for another 6
hours, when the QPF forecast diminishes to 0.01 or less for
nearly all areas. Light accumulations continue overnight and
then Sunday afternoon the accumulations start to increase, but
most accumulations are below 0.08 of an inch for each 6 hour
period, save for a few in the central Idaho mountains. That
light accretion should not warrant highlights for the rest of
this near-term period with limited areas on Sun/Sun night and
just a few more areas on Mon/Mon night.

The reason for the light accumulations is partially caused by
the continued mild temperatures for the time of year. Widespread
40s for highs in the Snake River plain and even middle to upper
30s for a location like Stanley indicate just how warm it is
expected to be. The cloud cover, except for tonight, will keep
overnight lows mild the subsequent nights in this period.

Another forecast element of concern is the windy to very windy
conditions in the Snake River plain, the eastern Magic Valley,
and the southern highlands. Since there is little vertical
mixing, the very strong wind aloft appears to be staying there,
away from the surface. The strongest winds are expected prior to
noon today, with a gradual dropoff overnight. By Sun morning,
it should return to 17KT/20mph or less sustained.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 159 AM MST Sat Dec 6 2025

Cluster analysis indicates that about 65 to 75 percent of the
members indicate a continued warm 500mb anomaly with the storm
track staying right where it is, which puts eastern Idaho on the
warm side but very close to the storm track. The remainder of
the solutions pump up the upper level ridge on the coast to push
the storm track farther north and away from eastern Idaho, or
maybe just brush the northern edge of the forecast area. In
short, there is no high energy trough to break this down and
return cold temperatures and bring a massive snow storm in the
classic style. So this upper level northwest flow continues for
at least another week. Another surge of moisture occurs on Tue
night/Wed/Wed night. However, the temperatures appear to peak
with this feature, with Pocatello airport forecast to be in the
mid-50s! Not a record, but close. Even Stanley may warm to the
low 40s for a peak on Tue. Not good news for snow-makers, but
the precipitation will make up for an incredibly dry autumn.

One concern will be the wind. The GFS guidance has been
consistently forecasting a Wind Advisory/High Wind Warning event
with this mid-week storm mentioned above. The ECMWF is also very
strong and would verify a Wind Advisory.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1044 PM MST Fri Dec 5 2025

Steady precipitation is trying to taper off an hour or two early
this evening at a few terminals, and we`ve cautiously been able to
back off slightly on some cig/vsby impacts via amendments and the
06z TAFs as trends allow. Otherwise, forecast remains on track,
and LLWS concerns continue for the next 3-5 hours before the
strongest surface winds materialize and coincide with a slight
relaxing of the flow aloft. Previous discussion is below.

Issued at 449 PM MST Fri Dec 5 2025

Southeast Idaho is incredibly moist with another round of
organized/widespread rain and snow now moving in. The result will be
a period of IFR conditions for cigs/vsbys/BR (LIFR at KIDA which is
currently sitting below airfield minimums) into the overnight with
increasing WSW winds during and behind the precip. Precip should
shut down by 08-11z/1-4am, with low stratus a bit slower to
clear/lift with updated timing outlined in the latest TAFs. Winds
are rapidly increasing aloft first as we speak, so we have also
added periods of LLWS this evening into tonight before the flow
aloft starts to relax combined with better mixing to the surface.
West winds at 2,000 feet AGL may reach 50kts at KPIH and KBYI. If
you`re looking for VFR conditions, look toward sunrise for KSUN and
KBYI, and Saturday afternoon for everyone else, although it will
remain breezy throughout the day. Confidence is lowest on exactly
when clouds will try to retreat from KIDA and KDIJ.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 11 AM MST this morning for
IDZ058>066.
Winter Weather Advisory until 11 AM MST this morning for
IDZ072-073.

&&

$$

SHORT TERM...Messick
LONG TERM...Messick
AVIATION...01