172
FXUS65 KPIH 082331
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
531 PM MDT Mon Jun 8 2026

.KEY MESSAGES...

- Cold front passage overnight with localized gusty winds.

- Good chance for widespread showers and storms Tuesday into
  Wednesday morning

- Drying and warming trends along with breezy conditions later
  in the week through the weekend.

&&

.DISCUSSION...
Issued at 201 PM MDT Mon Jun 8 2026

Satellite imagery shows shortwave trough just off PacNW coast
this afternoon, poised to impact East Idaho beginning overnight.
Cloud cover increases through the remainder of the day, and a
few showers will be possible by late evening in the central
mountains ahead of the leading surface front arriving overnight.
This front is associated with very strong 700mb jet, and a
negatively tilted 500mb shortwave axis. Isolated showers or
thunderstorms will be possible with the passage of the front,
and gusty outflow winds will be possible. The airmass over East
Idaho starts out dry, though dewpoints are expected to slowly
increase through the day ahead of the front. Any convection
associated with the front will likely be mostly virga with
little precipitation, but strong gusty winds will be briefly
possible with passage of the front during the overnight. HRRR
forecast surface gusts have exceeded 45kts at times overnight,
suggesting that isolated gusts associated with frontal passage
may exceed 50 mph at times. However, most gusts will likely
remain in the 35-40 mph range, as HREF probabilities only
support a 35-50% chance of gusts exceeding 45 mph with frontal
passage. Behind the front, showers steadily increase the
potential for rainfall to reach the ground by sunrise. Post-
frontal showers are expected most areas during the day Tuesday,
with most of East Idaho expected to see wetting rains over 0.10"
by midnight Tuesday night, and a greater than 75% chance for
0.25" or more across the Sawtooths, Frank Church, and higher
elevations in the southern and eastern highlands. There is a
chance for thunderstorms, especially in the eastern highlands
Tuesday afternoon, with strong gusty winds and small hail.
Strong winds are forecast in the northern portions of the Snake
Plain during the day Tuesday behind the main front, and a WIND
ADVISORY has been issued for the INL east to Idaho Falls and
Rexburg, along with a LAKE WIND ADVISORY for American Falls
Reservoir.

Shortwave shifts east overnight Tuesday night, but second weak
feature drives across the panhandle into Montana during the day
Wednesday. Additional isolated showers and thunderstorms will be
possible mainly across the Island Park region. Strong westerly
winds are forecast for the Eastern Magic Valley and Lower Snake
Plain, and another WIND ADVISORY will likely be needed. Dry
westerly flow is expected Thursday into the early weekend,
gradually shifting to northwest flow as a ridge of high pressure
builds into the coastal states. There is potential for a
shortwave to drop through Montana late Saturday into Sunday, but
moisture appears to stay too far northeast to impact the region.
Breezy winds will be possible. Temperatures rebound back into
the upper 70s to mid 80s Friday through the weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 521 PM MDT Mon Jun 8 2026

Cold frontal system moving through tonight and main impact will
be a low probability of a brief period of thunderstorms around
midnight or shortly after at all sites. Put prob 30 in all the
TAFS. Low confidence in that but gusts may reach 30 knots or
above if a thunderstorm occurs. Likely to see some rain as well
after 06 to 09Z through Tuesday morning. Winds will increase
substantially after 18Z with sustained 15 to 25 knots and gusts
25 to 35 knots at all sites. A chance of thunderstorms mainly at
DIJ after 18Z.

&&

.FIRE WEATHER...
Issued at 1142 AM MDT Mon Jun 8 2026

Min RHs remain low today (below 15% for Fire Weather zones 425
and 427) with overall lighter gusts early today ahead of a
system approaching that will come through tomorrow. Expect gusts
of near 25 to 30 mph especially for western and northern ridge
tops by late afternoon/early evening.

On Tuesday expect strong winds gusts (35 to 50 mph) with
increased RHs (min RHs of 25 to 60S%) with scattered showers and
isolated to scattered thunderstorms Tuesday with wetting rains
likely for higher elevations. Precipitation chances continue
into Wednesday morning mainly for Fire Weather zone 411.

Temperatures remain below normal through Wednesday with drying
and warming trends along with breezy conditions later in the
week through the weekend.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 10 AM to 9 PM MDT Tuesday for IDZ052-053.

&&

$$

DISCUSSION...DMH
AVIATION...GK
FIRE WEATHER...TW