916
FXUS65 KPIH 100650
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1250 AM MDT Sat Oct 10 2026

.KEY MESSAGES...

- Flood Watch In Effect (TodayMonday): A Flood Watch covers
  most of eastern Idahoincluding Sun Valley east through the
  Magic Valley, Snake Plain, and Eastern/Southeastern
  Highlandsfor a multi-day rainfall event of 1.0 to 2.0 inches,
  with localized totals closer to 3.0 inches

- Dramatic Weekend Cooldown: Today`s upper 70s and 80s mark the
  final warm day of the season. Highs drop below 70 on Saturday
  and plummet into the 40s and 50s on Sunday.

- Frost/Freeze Headlines Ahead: Widespread cool temperatures
  will bring frost/freeze risks starting Sunday morning,
  becoming more likely Monday through mid-week before headlines
  are suspended for the season.

&&

.DISCUSSION...
Issued at 1249 AM MDT Sat Oct 10 2026

Light rain showers/virga have been slowing expanding overnight,
and the trend will just continue today. We will see an uptick of
precipitation amounts late this morning across the southeast
corner, and then most areas outside of the central mountains
this afternoon. We do expect thunderstorms today, and there is
the potential in addition to some decent downpours, to see some
stronger winds. There is a 20-70% chance for gusts over 35 mph,
perhaps exceeding 45...IF we can get some stronger storms to
fire today. Otherwise, precipitation amounts quickly ramp up
starting tonight and continuing through Monday morning. There is
still some "wobbling" on where the heaviest amounts will fall,
but there is still a pretty wide swath of 1-2" amounts across
central and eastern Idaho. It still looks like the "drier" spots
will be across Lava Beds where 0.50-1.0" amounts are possible.
It also looks like once you get into areas west of US-93 and
north of ID-75, 0.30-0.80" is possible. We have widened the area
of where we are more likely to see, and have in the official
forecast, over 2"...generally east of a line from Monida Pass to
around Juniper and Sweetzer Summit. It is likely we will see
localized amounts around 3" along and east of I-15. Some of the
wobbling is due to the models showing some uncertainty where
some of the heaviest bands end up Sunday into Monday. The trend
has been to keep split flow, BUT instead of the main closed low
being offshore or over California...the trend is shifting
northeast toward the Sierras to central Utah. Looking at the
higher end of the Blend of Models, we are coming in at or just
above the 90th percentile mark in terms of heavier amounts. The
absolute highest amounts with the Blend are still running in the
2-4" range...and 4"+ in spots across the eastern and southeast
highlands. Those amounts would represent a very, very low
probability but higher impact situation. Given the pattern and
the influences from Rachel, it is possible we see some isolated
high-end amounts. Needless to say, the FLOOD WATCH remains in
place. We may need to expand the areal extent into the central
mountains depending upon trends in the models, or at least
consider watches for the Ohio and/or Wapiti Burn Scars. We must
neglect that colder air is going produce some snow at highest
elevations of the central mountains and along the Montana
border. While we might see a few spots below 8000ft with some
brief snow accumulation, that still looks like the lowest we see
decent accumulations. We could see over 6" on the highest peaks,
9500-10000ft, and certainly once you get north into Montana
where the coldest air will stay.

It will take until Wednesday or Thursday to see low pressure
shift east of the Rockies. Lingering showers and cooler
temperatures will remain in place through then. High pressure
should begin to slowly return later next week. Temperatures will
slowly climb back into the 60s for highs in the valleys.



&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1030 PM MDT Fri Oct 9 2026

Showers have dropped off this evening. Wind has dropped off
currently as well. Look for a quick round of showers early
Saturday before a brief break ahead of isolated to scattered
showers and storms Saturday afternoon. Have left all
precipitation as VCSH Saturday until can determine timing on
rain showers. The intensity of thunderstorms on Saturday
afternoon remains questionable as temperatures will be dropping
by that point. SUN looks to stay the driest on Saturday, but
should join in on the action by late Saturday night or early
Sunday morning. At this point, mostly VFR conditions will
continue, but that becomes less likely as clouds lower and
rainfall increases Saturday night into Sunday. Guidance is
showing most sites, except SUN and maybe BYI, starting to drop
to MVFR between 3 to 6Z on Saturday evening. Precipitation will
become more than just VCSH Saturday evening into early Sunday
morning for all sites.

&&

.FIRE WEATHER...
Issued at 1249 AM MDT Sat Oct 10 2026

Showers and thunderstorms slowly expand through the day, with
the bulk of the precipitation still expected Sunday into Monday
across central and eastern Idaho. Today, while we still have
some drier air in place, may see storms with some gusty winds
(20-70% for gusts over 35 mph). The trend for widespread 1-2"
totals is there over much of central and eastern Idaho. The
"drier" spots will be from north of ID-75 and west of US-93 in
the central mountains, where 0.30-0.80" is still possible. The
other main area of lower amounts is west of US 93 across the
Magic Valley where 0.50-1.0" is possible. We are still expecting
amounts in excess of 2" in some spots along and east of
I-15...trying to approach 3" locally. The higher end of the
Blend still is trying to paint widespread 1.5-3.0" amounts,
locally push 3.5"...and the absolute highest in the 2-4" range
areawide with places in excess of 4". The higher end amounts are
certainly a possibility due to pattern and strong influence from
Rachel. Snowfall is still confined to above 8000ft in the
central mountains and along the Montana border. It is possible
we could see brief snowfall/accumulation in colder basins,
though. Showers will linger through midweek as low pressure will
be slow to move into the Plains, although expect much less
precipitation after Monday. High pressure looks to rebuild late
next week, with a slow warming trend currently forecast.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Flood Watch from noon MDT today through Monday afternoon for
IDZ051>067-073-075.

&&

$$

DISCUSSION...Keyes
AVIATION...TW
FIRE WEATHER...Keyes