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FXUS65 KPIH 091110
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
510 AM MDT Fri Oct 9 2026

.KEY MESSAGES...

- Increasing winds this afternoon with near-critical to critical
  fire weather conditions

- A few sprinkles/virga with gusts over 35 mph possible this
  afternoon and evening

- Rain and mountain snow increases tomorrow and continues
  through Monday

&&

.DISCUSSION...
Issued at 1145 PM MDT Thu Oct 8 2026

Our major pattern shift begins today as low pressure begins to
drops across western Canada. This will produce gusty winds
across a good chunk of eastern Idaho. Gusts in the 25-35 mph are
expected, with some gusts closer to 40 mph across the central
mountains. We should also see some mid level clouds developing
the area this afternoon. The concern isn`t necessarily rain, as
it should be way too dry to get measurable rain at least
initially. The concern is sprinkles/virga and enhance wind
gusts. There is a 10-50% chance for gusts over 35 mph for late
afternoon into the evening hours. While the chance is extremely
low, we might even see a couple of thunderstorms. Overnight, we
do expect a slow uptick in the potential for trace rainfall
amounts or may a couple of hundredths worth of rain, mainly
across higher elevations. Temperatures will actually be a bit
warmer today especially where we might get a little bit of help
from downslope. That said, it still will be in the mid 70s to
mid 80s for the valley. We can say goodbye to those temperatures
for a bit after today.

Showers and storms will begin to increase tomorrow fairly
quickly once we get later in the day. By tomorrow night and
lasting into Monday, more widespread rain and mountain snow is
likely with some embedded thunderstorms. The pattern, although
showing some minor shifts across the western U.S. still develops
a strong closed low across California, as the flow splits. The
northern end of the split maintains a slow moving through
extending through western and central Idaho and north into
Canada. We are staying on the warm side of the storm through
Monday. This is helping keep mountain snowfall potential north
across Montana except for the trough/area of low pressure across
central Idaho and around Island Park. The pattern also holds
taking the remnants of Rachel all the way north into Utah,
Wyoming and Idaho. We continue to refine and increase
precipitation amounts, as it does appear there is still a shift
to the west with heavier precipitation. The latest forecast has
more widespread amounts of 1-2" now back across the Snake Plain
and into the central mountains from the Wood River Valley
through the southeast corner of Lemhi County. There is still
some expectation we could see totals above 2" along and east of
I-15. Even where we may not see 1"+ precipitation amounts
across the central mountains, totals are still running
0.40-0.90". If you look at the higher end of the Blend of Model
rainfall totals, it is showing widespread 1.5-3.0"...highest
across the same strip of the central mountains as well as the
eastern and southeast highlands. The absolute highest in the
Blend is coming in at 2.0-3.5" and locally higher near 4" in a
few spots. While the absolute highest have a very low chance of
occurring, some areas seeing amounts of 2-3" is definitely out
of the question.Based on the current trends accumulating snow is
confined to mostly above 8000ft now. Light amounts are still
expected, but highest peak and ridgelines may indeed several
inches of wet snow accumulation across the central mountains and
along the Montana border.

Low pressure remains across the region through midweek, so do
expect show showers to stick around along with those cooler
temperatures. Most versions of the GFS and ECMWF (including
ensembles) show high pressure redeveloping across the West later
next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 506 AM MDT Fri Oct 9 2026

Winds will rapidly increase this afternoon across central and
eastern Idaho. We will see gusts of 15-25kts this afternoon
along with an increase in mid-level clouds. We will likely see
some virga, but may see some sprinkles or light showers with
this. IF we see anything measurable, it might be near SUN...but
confidence and coverage is too low to even mention VCSH. A
thunderstorm or two might occur, but confidence and potential is
very, very low. We will see gusty winds persist past sunset at
PIH, IDA, and DIJ. SUN will likely see a few hours of southwest
wind or at least bouncing around from Southeast to Southwest
this afternoon.

&&

.FIRE WEATHER...
Issued at 1145 PM MDT Thu Oct 8 2026

Our pattern shift starts today, in the form of stronger wind and
increasing mid level clouds. We are expecting gusts in the 25-35
mph range to be pretty common by this afternoon, with some
gusts closer to 40 mph in the central mountains. Humidity does
come up a bit in the central mountains and the far southeast
corner, expect pretty dry air to remain in place today. We will
maintain a RED FLAG WARNING for Zone 427 due to drier fuels and
stronger gusts. With the mid level clouds developing later
today, we are may actually see some virga or sprinkles and
enhanced gusty winds. We did add isolated "showers" mainly over
higher terrain, although it does appear some measurable rain is
possible across portions of the central mountains overnight. The
potential for gusts over 35 mph is 10-50% for areas outside of
the central mountains.

Starting tomorrow and through Monday, showers and embedded
thunderstorms become more widespread. The trend has been to
bring higher rainfall totals as far west as from the Wood River
Valley through southeast Lemhi County, and points east from
there. Snowfall is still possible across the central mountains
and along the Montana border, but accumulations are really
limited above 8000` and higher. Precipitation totals across
Zone 475 and the Stanley end of 422 are currently running at
0.35-0.90", as well as the west of U.S 93 across the Magic
Valley. Otherwise, more widespread 1-2" totals are now in the
forecast, with some pockets over 2" along and east of I-15. The
higher end of the Blend of Models forecast has widespread
1.5-3.0", with absolute highest totals hitting 2.0-3.5" with a
few spots closer to 4". While these highest end amounts have a
extremely low chance of occurring, it is plausible given the
influence from Rachel.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 2 PM this afternoon to 8 PM MDT this
evening for IDZ427.|

&&

$$

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