741
FXUS65 KPIH 052209
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
409 PM MDT Sat Sep 5 2026

.KEY MESSAGES...

- Showers and thunderstorms mostly across the central mountains
  through tomorrow morning

- Better chance of showers and thunderstorms tomorrow evening
  through Monday for all of central and eastern Idaho

- Breezy conditions through Labor Day expected

&&

.DISCUSSION...
Issued at 1205 PM MDT Sat Sep 5 2026

The trend still remains for whatever shower and thunderstorm
activity is out there through Sunday morning to remain across
the central mountains. We will have to watch late this afternoon
and evening for the potential for development from Jackpot up
through Hailey, which is a little farther south from where the
current forecast has things redeveloping. Even if we see that
development, it quickly shifts north into the central mountains
by late evening. Otherwise, looks for breezy southerly winds.
Gusts of 25-35 mph will be common through this evening,
lingering across the southeast highlands up through the Teton
Valley with downsloping into the Snake Plain from Pocatello
north. The main issues remain for tomorrow night and Labor Day -
increasing showers and thunderstorms followed by stronger winds
late in the day. We may catch a small amount of moisture from
Marie closer to the Wyoming border, but amounts even with that
possibility continue to drop off. The best chance of rainfall
looks more and more plausible over portions of the central
mountains associated with low itself. Most areas now will only
see a few hundredths to around 0.30", including in the
mountains. We may see up 0.50" across higher elevations of the
eastern highlands, with a 30-50% chance of exceeding that
amount. Areas north of Stanley and through the Frank Church are
looking at 0.40-0.70" with the latest forecast, with a 40-60%
chance of more than 0.75". Showers and storm will clear most
areas by afternoon except for the central mountains and along
the Montana border, and all areas by midnight. Winds ahead of
showers and storms tomorrow will be out of the south and
southwest at 15-30 mph (sustained and gusts) with some spots
seeing gusts around 35-40 mph. Adding in potential gusts with
storms, we could see outflow winds approaching 50-60 mph
tomorrow afternoon and evening. There is a MARGINAL RISK for
severe storms over most of eastern Idaho for this reason. On
Labor Day, winds will be west to southwest...strongest from the
Magic Valley up into southwest Montana. Sustained 25-35 mph with
gusts above 40 mph are possible, pushing WIND ADVISORY
thresholds across the Arco Desert. There will be a very sharp
contrast tomorrow vs Monday with temperatures. We will 70s and
low 80s for highs in the valleys Sunday. Monday will be 10-15
degrees COOLER with only a few spots possibly getting above 70.
It will be cold enough Monday with the low crossing the central
mountains to see a rain/snow mix or brief period of all snow for
elevations above 10,000ft!

Tuesday looks dry, and so does most of Wednesday. (We might see
a few random showers in the afternoon). There is a slightly
higher chance of showers and storms Thursday, but likely
increases steadily into next weekend. Temperatures rebound with
70s and 80s quickly returning at the end of the upcoming week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 409 PM MDT Sat Sep 5 2026

Somewhat breezy conditions around PIH and IDA should
diminish this evening. A few showers may work into the SUN area late
this evening and overnight. But no significant impacts expected.
Next round of convection which may affect other sites will hold
off until late tomorrow afternoon.

&&

.FIRE WEATHER...
Issued at 1205 PM MDT Sat Sep 5 2026

Showers and isolated thunderstorms will remain across the
central mountains through tomorrow morning. Amounts should
remain light, with a few stronger storms MAYBE producing locally
heavier rainfall. Outside of that, looks for gusty winds and the
potential for near-critical to locally critical fire weather
conditions due to marginal humidity. We have seen a few spots
across Zones 410, 413, and/or 427 occasionally pushing into
criteria for a handful of hours each day. That trend continues
across Zone 413 and perhaps 410. Ahead of the moisture push
tomorrow, we will likely see this across Zones 410, 425, and
427. With very limited impact from Marie in terms of rainfall
amounts tomorrow and Labor Day, totals have continued to drop
outside of the central mountains where higher amounts persist
with the low moving through the area. Most areas will see
anywhere from a few hundredths to around 0.30" including higher
elevations. The exceptions will be along the Montana border in
Zone 411 and north of Stanley through the Frank Church into
Lemhi County in Zones 422 and 475. For Zone 411, look for up
0.50" with a 30-50% chance of exceeding that amount. For Zone
422 and 475, look for 0.40-0.70" with the latest forecast, with
a 40-60% chance of more than 0.75". It does appears a brief
period of snow or a mix is expected Monday across the central
mountains above 10,000ft. We may stronger storms producing
gusts over 35 mph with some potential for gusts of 50-60 mph. On
the back side of the low Monday, stronger west to southwest
winds will develop mainly across Zones 410 and 425 with gusts of
35-45 mph are possible. It will breezy elsewhere, but not as
strong.

Dry conditions return for midweek with temperatures quickly
rebounding. Showers and thunderstorm chances pick up again
toward the end of next week.

&&

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

&&

$$

DISCUSSION...Keyes
AVIATION...13
FIRE WEATHER...Keyes