194
FXUS65 KPIH 281910
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
110 PM MDT Wed Oct 28 2026

.KEY MESSAGES...

- Mostly dry today and Thursday.

- Cool again today before warming slightly for Thursday
  and Friday.

- Expect a wet, chilly Halloween/weekend, especially
  on Sunday.

&&

.DISCUSSION...
Issued at 1204 PM MDT Wed Oct 28 2026

There is currently dry, zonal flow aloft over southern Idaho.
Also, currently there is an upper level low centered just off
the coast of central British Columbia with another upper level
low centered off the coast of central California. These upper
level lows will drive the weather/precipitation over the
upcoming weekend.

Today will be dry as we transition from zonal flow aloft to
southwesterly flow aloft. Highs today will be very similar to
yesterday, generally in the mid 40s to low 50s. Wind gusts today
will be around 25 mph across the Arco Desert/INL and around 15
to 20 mph elsewhere.

The bulk of Thursday will also be dry as temperatures warm just
a few degrees with southwesterly flow aloft. Thursday morning
look for patchy fog, especially in lower elevations near water
sources. Expect temperatures in the low to mid 50s for most
lower elevations on Thursday. Look for overall light winds
Thursday too.

By very late Thursday night or very early Friday morning, our
next system is just beginning to bring the start of some
precipitation to southeastern Idaho. An area of low pressure off
the coasts of the Washington and Oregon will be just starting
to pull in some Pacific moisture into southeastern Idaho. It is
this low off the Oregon and Washington coasts that moves inland
during the weekend bringing cooler air and good precipitation
chances. Deep troughing over the West will transport even more
moisture into our area from the other upper level low over
Southern California going into late Saturday and, especially,
Sunday.

The current trend has been to decrease QPF on Friday, allowing
temperatures to stay "warm" for one more day before more
organized showers arrive for the weekend and bring a cool down.
On Friday, the more limited precipitation we do have around will
likely favor parts of the Central Mountains. The rest of the
higher elevations will start to receive precipitation Friday
afternoon/evening before showers become more widespread and
steady late Saturday into Sunday. Saturday late afternoon into
the early evening models still show a chance for 0.02 to 0.10 of
rain across lower elevations that will likely have impacts on
Halloween activities. The bulk of the precipitation is still
arriving late Saturday through Sunday and lingering into Monday
morning.

While total QPF numbers continue to change from model
run to model run, there currently is at least a 50-70 percent
chance that all of our CWA across southeastern Idaho sees at
least 0.25 inch of precipitation from Saturday morning to
Monday morning. Plus, for some higher elevations, especially the
farther east you go, those 48-hour totals will likely be closer
to 0.75-1.50 of liquid precipitation. Temperatures will also
drop with highs on Sunday and Monday being the low to mid 40s
for most areas. As a result, expect better snow amounts
especially for our northern areas (Central mountains and the
Montana Divide) above 6500 to 7500 feet with 6 to 12 inches of
snow likely for Central mountains (to include the Salmon river
mountains, Sawtooth mountains, West Smokys mountains, Smoky
mountains, White Cloud mountains, Boulder mountains, Pioneer
mountains, White Knob mountains and the Lost river range).
Higher elevations for the Pioneers and Big Lost range could see
up to 18 inches of snow. Galena Summit has 12 inches of snow
currently forecasted. Areas across the Montana Divide will see 6
to 12 inches of snow above 7000 to 7500 feet as well. The
Eastern Highlands is a little less certain with snow levels. The
snow levels look to be higher when more precipitation moves
through on Sunday, with snow levels around 8000 to 9000 feet.
These areas, especially in the Wasatch Idaho mountains above
8000 to 9000 feet, will get 6 to 12 inches of snow too.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 532 AM MDT Wed Oct 28 2026

Predominant VFR expected through the period as we have dry weather
in place before a system moves in for the weekend. Winds should be
light and generally variable aside from the KSUN diurnal wind
regime. As has been the case for the past few days, there is a non-
zero chance for some low CIGs at area terminals but chances are too
low to include in the forecast.

&&

.FIRE WEATHER...
Issued at 239 AM MDT Wed Oct 28 2026

Dry conditions expected for today and tomorrow as we transition from
zonal flow to southwesterly flow aloft. This will warm us up a few
degrees, but min RHs will still be around 40-50 percent across the
whole area. Wind gusts today will be in the 15-25 mph range.
Precipitation returns to the forecast very early Friday morning for
the Central Mountains and then spread eastward and becomes more
widespread through the weekend. While total QPF numbers continue to
change from model run to model run, there currently is at least a 50-
60 percent chance that all of our CWA sees at least a quarter inch
of precipitation from Saturday morning to Monday morning and in some
higher elevations especially the farther east you go, those 48-hour
totals may be closer to 0.75-1.00 of liquid precipitation.

&&

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

&&

$$

DISCUSSION...TW
AVIATION...McKaughan
FIRE WEATHER...AMM