310
FXUS65 KPIH 041112
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
512 AM MDT Mon Aug 4 2025

.KEY MESSAGES...

- Critical Fire Weather Conditions Due To Wind and Humidity

- Potential For Thunderstorms Today and the End of the Week

- Temperature Rollercoaster Throughout the Week

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 118 AM MDT Mon Aug 4 2025

A bit of virga and lightning occurred overnight with limited mid
level moisture, although not much in the way of wind was noted.
We will see thunderstorm potential increase today, especially
across portions of the central mountains and along the Montana
border. Gusty winds will be the main issue with storms, although
the potential for winds over 35 mph is only 10-30% mph most
areas, with a 50%+ potential from Challis north into Lemhi
County. The highest gust potential looks to be around 45 mph
according the HREF, with MAYBE 60mph+ for any storm that can
form and move across the Magic Valley and Snake Plain...which
right now is only 10-20%. Outside of storms, it will be breezy
as the next low moves through the Idaho Panhandle into Montana.
The strongest gusts appear to be across portions of the central
mountains and the Lava Beds/Arco Desert areas...where gusts up
to 35 mph are forecast. For now, we are seeing anything strong
enough for any wind-related headlines outside of fire concerns.

For Tuesday, we actually are NOT looking for any storms. Wind
gusts will be down, except for across the Arco Desert where we
could still see gusts 30-35 mph in the afternoon. Temperatures
will remain "cooler" than previous days. Highs are barely
pushing mid and upper 80s for our typical warmer spots today and
Tuesday. It is that time of year though that with drier air in
place, colder spots in the central mountains at night are
dropping to or just below freezing. Welcome to August!

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 118 AM MDT Mon Aug 4 2025

Wednesday looks dry and bit warmer, with some low 90s popping
back up in the forecast. Strongest wind gusts are 25-30 mph in
spots during the afternoon. Another low impacts portions of the
Northern U.S. for Thursday and Friday. It will be breezy again,
with a low chance of storms across northern areas. We will watch
trends to see where storm potential ends up being during that
stretch. Friday looks to be pretty "cool" for August standards,
with widespread highs in the mid 70s to low 80s down low. Never
fear though, as dry and warmer conditions return over the
weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 506 AM MDT Mon Aug 4 2025

Another day of TSRA in store, including a marginal chance of
severe TSRA (with G58+KT and GR) for KSUN. The risk at KBYI,
KSUN, and KPIH are low enough where PROB30 is too much with risk
on the order of 10-15 percent. But this will have to be
monitored as a number of deterministic models bring storm cells
through KPIH. Saw very little for KBYI and KSUN. Expect
increasing wind in the afternoon with the approach of a trough
from the west that is centered so that it will go through
central ID and western MT later tonight. As the low pulls away,
skies should improve, although even now do not see any impactful
CIGs, with it staying mid-level clouds or higher. Tue is
expected to be much more stable with an end to afternoon and
evening TSRA, at least through Wed. Southwest frontal boundary
wind should kick in by mid-afternoon and may see a shift to
northwest and north during the overnight, but many places will
be fairly light.

&&

.FIRE WEATHER...
Issued at 118 AM MDT Mon Aug 4 2025

Upper level trough will swing through north central ID and the
Panhandle, lifting into western MT by Mon night. This will trigger
thunderstorm activity mostly in northern areas, where scattered
coverage is possible over the Salmon-Challis NF and a small portion
of the northern Sawtooth NF. In the southern half of the forecast
area, thunderstorm coverage is limited to the Targhee NF and some of
the southern Sawtooth NF. This trough will cool temperatures down 5
deg F or so for Tue, but not do much for afternoon humidity readings
in the eastern Idaho Dispatch area. By Wed, temperatures have warmed
and there are widespread afternoon humidity readings below 15
percent everywhere but the extreme western end of the ID-SCF and
extreme northern end of the ID-STF.

High instability is expected today, especially in the southern tier
bordering UT and the Targhee NF. This is producing strong transport
wind and high mixing heights. This does not carry into Tue, as the
trough brings in stable conditions for Tue and Wed, with no
thunderstorm activity expected.

Wind will stay elevated through these three days. Today, the trough
is pushing the wind stronger and the instability means that gusts
will reach critical thresholds and combine with the low humidity at
the lower elevations of the Eastern Idaho Dispatch area for Red Flag
conditions, so the Warning will continue. The upper level pattern
keeps a longwave trough at the coast and the trough that triggers
the event today will have moved into Canada by Tue afternoon with a
ridge axis to the east of the forecast area. This produces a
favorable upper level wind from the southwest with a moderate to
strong summer gradient to support breezy to windy conditions. With
drier afternoon humidity on Tue and especially Wed, Red Flag
conditions should spread to the south and west, possibly even into
the Targhee NF.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 2 PM this afternoon to 9 PM MDT this
evening for IDZ410-413.

&&

$$

SHORT TERM...Keyes
LONG TERM...Keyes
AVIATION...GK/Messick
FIRE WEATHER...Messick