152
FXUS65 KPIH 300515
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1115 PM MDT Fri Aug 29 2025

.KEY MESSAGES...

- Isolated thunderstorms this afternoon and evening.

- Turning drier and a little warmer for Labor Day weekend.

- Dry pattern continues through most of next week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 152 PM MDT Fri Aug 29 2025

Satellite imagery shows pair of weak shortwaves impacting East Idaho
this afternoon. The first shifting into the state from
Oregon/Washington, helping to fire isolated thunderstorms across
portions of the central mountains, mainly south of the Lost River
Valley. Second shortwave sliding across northern Nevada/Utah this
afternoon helping to fire a few thunderstorms across the
southern/southeast highlands. High-res models particularly HRRR and
WRF picked up on the central mountain development, but all of them
missed out on the development across the south where weakly
northwest flow providing some additional orographic help. WRF was
the closest, but still kept bulk of the convection south of the UT
border and a few hours later. Have adjusted PoPs this afternoon and
early evening to try to account for these areas. Also some concern
for the central mountain convection to spill out into the Snake
Plain late this afternoon into the evening, and even if it doesn`t,
will also be keeping an eye out for outflow boundaries that traverse
the Snake Plain toward the I-15 corridor, just enough for minor
impacts but not expected to approach severe. Both HRRR and WRF also
keep some convection going after 03Z, but opted to allow PoPs to
drop off after that time period, for now. Remainder of tonight looks
dry and continued cool, but seeing some very weak low confidence
potential of isolated development on Friday across the central
mountains once again. There is less of a signal on less of the high-
res cams, and NBM maintains dry conditions. If anything, believe
this would be more favorable for an isolated sprinkle from an
over-zealous cumulus rather than a thunderstorm concern.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 152 PM MDT Fri Aug 29 2025

Models remain bullish on development of strong ridge through the
Great Basin into Idaho for the Labor Day weekend, continuing well
into next week. There are some differences in the ensemble clusters
with regard to how much influence the low off the Pacific coast will
influence the coast, and thus there are some very minor differences
in how much convective potential can be realized any particular
afternoon, especially for Tuesday and beyond. The NBM means have
backed off considerably on any kind of mention of thunderstorms
until late next week, but the 90th percentiles QPF do develop some
very light amounts each afternoon across higher elevations, so still
can`t completely rule it out at this time. Daytime highs still look
stable with daytime highs remaining in the 90s throughout the
period.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1115 PM MDT Fri Aug 29 2025

A few high clouds will pass through the region through
12z. Otherwise, looking at dry weather, vfr conditions, and mainly
light winds at all TAF sites over the next 24 hours.

&&

.FIRE WEATHER...
Issued at 152 PM MDT Fri Aug 29 2025

Drier weather is slowly taking hold over the region although we will
have one more day of at least some isolated precipitation chances
before drying out for the holiday weekend and continuing into early
next week. Expect some isolated showers/storms to develop this
afternoon and evening, especially over terrain, with these
diminishing as we get to around sunset. The weekend looks dry as
high pressure settles over the area and temps will gradually rise
accordingly to around seasonal levels. This should keep wind and RH
concerns low as we move into the first week of September.

&&

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

&&

$$

SHORT TERM...DMH
LONG TERM...DMH
AVIATION...Messick
FIRE WEATHER...McKaughan