459
FXUS65 KPIH 061246
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
646 AM MDT Sat Sep 6 2025

.KEY MESSAGES...

- Thunderstorm threat expands to everywhere by this early
  evening. Thunderstorm threat increases further on Sunday.

- Cloud cover and precipitation will bring a gradual cooling in
  both highs and lows today through Friday.

- Gusty wind outside of thunderstorms both this afternoon and
  Sunday afternoon.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 200 AM MDT Sat Sep 6 2025

Upper level trough to the west will slowly push eastward,
bringing increased southwest to south wind today, then more
westerly on Sunday. This southerly airflow will bring in moist
unstable air that will act as a trigger for thunderstorms both
today and Sunday, both for the afternoons and evenings. The
stronger flow aloft on Sunday will mean the potential for
stronger wind gusts Sunday after a prolonged period of light
wind. A break in the moisture flow from the west on Mon will
provide a break in precipitation and thunderstorms.

The increase in cloud cover and eventual shift to westerly
flow will allow temperatures to have a gradual cooling trend to
both highs and lows into the medium range forecast.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 200 AM MDT Sat Sep 6 2025

An upper level trough is expected to slowly move across the
western states during this period. There are a variety of
solutions in the clusters, with no cluster having more than a 30
percent chance of occurrence, so any timing has low confidence
and the threat of showers continues each day and evening, with a
reduced but continuing threat of thunderstorms.

The cooling trend for highs and lows continues through this
period.

The risk of showers peaks on Thu, then a gradual drying seems to
develop in the NBM guidance.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 641 AM MDT Sat Sep 6 2025

Thunderstorm probabilities this afternoon reach PROB30 category,
mostly 25 to 35 percent chance of occurrence over a period
anywhere from 2 to 6 hours. The risk shifts from west to east
across eastern Idaho so KDIJ will not see that kind of risk
until 06/21Z, western airdromes should start seeing that kind of
risk until 06/19Z. Wind should not be impactful unless it is
thunderstorm outflow, and even that should be limited to around
25KT. CIGs should stay above FL100. VSBY could be limited to
marginal VFR due to FU, erroneously reported as HZ for weather
stations with no augmentation.

&&

.FIRE WEATHER...
Issued at 200 AM MDT Sat Sep 6 2025

Remnants of the southwest monsoon will make its way into eastern
and central Idaho for the next couple of days. This will
increase humidity and instability, pushing up the mixing heights
and increasing the chance of thunderstorm activity. There is a
break for Mon and Mon night, then showers return, with a reduced
chance of thunderstorms. This means a gradual cooling to both
highs and lows with humidity staying rather high both for
recovery and afternoon minimum.

&&

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

&&

$$

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