435
FXUS65 KPIH 171015
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
415 AM MDT Tue Jun 17 2025

.KEY MESSAGES...

- Slightly cooler for Tuesday, but much hotter by Thursday.

- Windy on Friday, then breezy and turning much cooler for the
upcoming weekend.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 228 AM MDT Tue Jun 17 2025

Upper level trough moved through the region during the overnight
hours, much faster than anticipated. As a result, shower and
thunderstorm potential looks much less than we`ve seen in previous
days. There still may be some cumulus build-up across the central
mountains into the upper Snake Plain and upper Snake Highlands this
afternoon, and maybe a stray shower as well. Temperatures still look
cooler, generally around 80 across the lower elevations. Wednesday
looks dry across the area and warmer with a ridge of high pressure
building into the region. Highs in the lower elevations will once
again be in the mid and upper 80s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 228 AM MDT Tue Jun 17 2025

Thursday will be the hottest day of the week thanks to high pressure
in place over Eastern Idaho. Highs will range from  the low to mid
90s throughout the Snake River Plain, eastern Magic Valley, and
parts of the South Hills. By Thursday evening, the ridge of high
pressure will begin to shift eastward, opening the door for a 10 to
20 percent chance of an isolated shower or storm up north near the
Island Park area. Thursday will still be breezy with gusts of 25 to
35 mph across much of our CWA. Look for wind gusts to increase to
the 30 to 40 mph range on Friday and Saturday. Highs will be a
couple of degrees cooler on Friday, but still in the 80s for most.
This pattern change comes an upper level low moves onshore into the
PNW Friday afternoon. By Saturday morning, both the ECMWF and GFS
show the low sitting over southeastern Washington/eastern Oregon.
Both models then show the low splitting as part moves northeast and
the other remains over parts of southeastern Oregon and western
Idaho. This system will bring increasing precipitation chances
beginning on Friday and lasting through the weekend. Temperatures
will fall through the weekend, too, with highs down in 60s and 70s
on Saturday and 50s and 60s on Sunday. Morning temperatures in the
Central Mountains will be in the 20s and 30s, so yes, we will likely
see some light snow in the mountains if the forecast holds.
Temperatures begin to rebound quickly as we start the new week with
high back in the 70s and low 80s by Tuesday afternoon.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 414 AM MDT Tue Jun 17 2025

Some mid level clouds will likely develop in the afternoon heating.
But any showers should remain away from TAF sites. A few gusts to 20
kts will be possible at PIH and BYI this afternoon, otherwise gusts
will likely remain below 15 kts at other TAF sites.

&&

.FIRE WEATHER...
Issued at 228 AM MDT Tue Jun 17 2025

Thunderstorm chances are even less today than they were yesterday
with only a 20 to 30 percent chance up around the Island Park area,
part of Fire Weather Zone 411. The rest of us will remain dry with
min RHs ranging from 15 to 25 percent in the lower elevations and 20
to 35 percent in the mid elevations. It will be a bit breezy at
times this afternoon with wind gusts of 20 to 30 mph across most of
Eastern Idaho. Temperatures heat up and we dry out even more on
Wednesday and Thursday with a ridge of high pressure over Eastern
Idaho. The pattern begins to change on Friday and winds increase and
temperatures drop slightly before a bigger drop for the weekend and
more widespread precipitation chances return. Parts of the Central
Mountains could even see some light snow this weekend.

&&

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

&&

$$

SHORT TERM...13
LONG TERM...AMM
AVIATION...13
FIRE WEATHER...AMM