108
FXUS65 KPIH 061854
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1254 PM MDT Sun Sep 6 2026

.KEY MESSAGES...

- Showers and thunderstorms expected this evening through
  tomorrow afternoon with strong winds and brief heavy rainfall

- Gusty winds outside of thunderstorms will continue tonight and
  Labor Day

- Much cooler Monday with warming temperatures through at least
  midweek

&&

.DISCUSSION...
Issued at 1241 PM MDT Sun Sep 6 2026

A few showers and thunderstorms continue early this afternoon
near the Salmon River, but will increase from the south later
today. Through tonight, we will continue to see coverage
increasing from the south, and separately across the central
mountains with the low itself. There is a MARGINAL RISK for
storms through tonight potentially producing 60+ mph winds. The
best chance for gusts over 35 mph are across the Snake Plain,
Magic Valley, and southeast highlands. The potential for severe
storms in mainly confined to the southeast highlands, with a few
storms elsewhere before midnight producing strong winds. With a
lack of moisture really from Marie, rainfall amounts continue to
dwindle each forecast. The consensus is that most areas will see
anywhere from a couple of hundredths to about 0.15". Across the
southeast corner, the Big Holes, and north of Stanley through
the Frank Church, up 0.30" is possible. There is a 40-60% chance
of exceeding the end of the range in those areas. This is
plausible especially if we get strong/severe storms going and/or
multiple storms moving over the same area. Any risk for
localized flooding/debris is VERY LOW at the moment given the
waning rainfall rates and totals. Showers and storms will end
late tomorrow afternoon, although a couple of higher resolution
models want to pop off a couple of thunderstorms north of
Challis and along the Montana border. Outside of thunderstorms,
we will see fairly gusty south winds today, switch to the west
and southwest tonight and Labor Day. Gusts in the 25-35 mph
range are possible at times, with gusts above 40 mph across the
Arco Desert behind the cold front. Temperatures will be 10-20
degrees COLDER tomorrow, 50s and 60s for the valleys. We may see
a few low 70s south of the Snake Plain toward the Utah border.
With the low crossing the central mountains and the coldest
air associated with that, we are still going to see a period of
rain and snow above 10,000ft tonight and tomorrow morning!

We will quickly dry out for midweek. The Blend of Models wants
to keep us dry, or at least any chance of showers or storms
below 10% now through Friday. We will be sandwiched between low
pressure to our north and a building high to our south. There is
some tropical moisture that works around the ridge and comes in
for Thursday and Friday, and believe it not COULD tap into the
remants of Marie for a slight boost. The latter remains to be
seem since it will be absorbed into a bigger low offshore, but
there does seem to be some connection to other sources of
tropical moisture as well. All of that means that don`t be
surprise to see the Blend of Models eventually increase the
chance of showers and storms if these trends continue to show
up. Even if we get some moisture in here, highs quickly push
back into the 70s and 80s by Wednesday. The better chance of
showers and storms should hold off until next weekend as low
pressure moves inland and crosses the northern Rockies.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1141 AM MDT Sun Sep 6 2026

Quiet conditions are in place early this afternoon, but we begin
to transition to breezy conditions with increasing moisture and
a threat for SHRA/TSRA by evening for all terminals. A few TSRA
will be able to generate gusts approaching 45kts, and will
maintain going PROB30 timing. Storms decrease overnight west to
east, but SHRA remain possible. Winds remain elevated overnight
into Monday morning as well, strongest at PIH and IDA where
sustained speeds will likely hover around 20kts and gusts around
30kts.

&&

.FIRE WEATHER...
Issued at 1241 PM MDT Sun Sep 6 2026

Showers and thunderstorms will increase through this evening,
and continue through tomorrow afternoon across central and
eastern Idaho. The best chance of rain and thunder will remain
across the central mountains (422/475/476) and along/east of
I-15 in Zones 410, 411, and 413. Most areas will see anywhere
from a couple of hundredths up to around 0.15". Amounts of
closer to 0.30" north of Stanley through areas west of U.S 93
(422 and 475), as well as across Zone 413 and the Big Holes.
There is a 40-60% chance of exceeding that amount in those
zones. It is plausible if we can get some stronger storms going
and/or see multiple storms over the same location. It also looks
like under the center of the low in the central mountains that a
short window of rain and snow is expected above 10,000ft. Storms
through tonight are capable of producing gusts over 35 mph and
potentially over 60 mph. The most likely areas to see the
highest winds will be across the southeast corner extending into
the Snake Plain. Strong southerly winds will continue through
this evening, before giving way to west and southwest on Labor
Day. Gusts of 25-35 mph outside of storms and marginal humidity
(dropping to near 15%) will create near-critical to locally
critical fire weather conditions across portions of Zones 410,
413, 425, and 427. Similar speeds are expected Monday, if not
slightly higher across the Arco Desert, however humidity comes
up quite a bit as temperatures will be 10-20 degrees colder than
today.

We still are expecting to be dry for midweek. We will need to
watch Thursday and Friday to see how much tropical moisture
works around the ridge to our south and back into Idaho from the
west. There appears to be a decent connection at the moment,
evern trying to STILL grab some surge from what`s left of Marie.
At the moment, the Blend of Models is dry or keeping any chance
under 10%. Temperatures should rebound quickly by Wednesday, as
highs jump back into the 70s and 80s.

&&

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

&&

$$

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