344
FXUS65 KPIH 031105
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
505 AM MDT Wed Sep 3 2025

.KEY MESSAGES...

- Patchy smoke will remain, especially northern areas, but
  conditions will improve over the weekend when precipitation
  returns.

- Warmer temperatures persist through Thursday

- Showers and storms return later in the week

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 133 AM MDT Wed Sep 3 2025

High pressure remains in place over the area with the ridge axis
over Idaho, though high pressure is starting to break down or
weaken. Expect mostly clear skies in the morning to partly
cloudy skies in the afternoon with overall light winds (gusts up
to 15 to 20 mph in the afternoon) today and tomorrow. High
temperatures the next couple of days still look to run in the
80s and low 90s, 4 to 8 degrees above normal. Moist southerly
flow will continue to move into our western areas, which will
allow some moisture to continue to move into the area. The
southern Hills/Albion mountains along with the Central mountains
will have some afternoon cumulus development, but very little,
if any, precipitation is expected today. Tomorrow, Thursday,
there is a slight chance of showers and thunderstorms over the
Central mountains as well as the southern Hills/Albion
mountains. There is still some lingering valley smoke/haze (AQI
in the low 50s) across our area with light smoke moving into
the area over the Montana Divide with high pressure starting to
break down. Expect air quality to improve this weekend with the
return of precipitation.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 112 PM MDT Tue Sep 2 2025

The long term forecast features a gradual cooling trend and overall
wetter conditions. In the second half of this week, the ridge of
high pressure currently over our area begins to break down a bit as
a shortwave is ejected off an area of low pressure off the coast of
British Columbia. This will allow for an influx in monsoon moisture
to begin moving into Eastern Idaho on Friday, especially for
Saturday, and lingering into Sunday and Monday of next week. This
will help cool us down a few degrees with highs falling from the low
90s on Thursday to the mid 80s on Friday and then into the mid and
upper 70s for Saturday and Sunday. We will begin to dry out next
Monday and Tuesday as the ridge of high pressure builds back in over
the area, but temperatures will hold steady right around 80 degrees
for most. At this point, the NBM shows a widespread 30 to 50 percent
chance of at least a tenth of an inch of QPF for all of Eastern
Idaho in the 24 hours from Saturday morning to Sunday morning.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 501 AM MDT Wed Sep 3 2025

Expect VFR conditions through the period under high pressure.
Look for overall light winds and mostly clear to partly cloudy
skies. Will likely see mid to upper-level clouds for all TAF
sites. DIJ and SUN will have the normal diurnal winds shifts.

&&

.FIRE WEATHER...
Issued at 133 AM MDT Wed Sep 3 2025

High pressure will bring mostly clear to partly cloudy skies,
warmer temperatures, and overall dry conditions the next couple
of days. Afternoon relative humidity will be mostly critical
today with poor overnight recovery Thursday morning within the
inversion layer. However, expect considerable relative humidity
improvement on Thursday with only a few areas (Arco desert and
Salmon valleys) dropping below 15% relative humidity in the
afternoon. Wednesday and, to a lesser degree, Thursday expect
above normal temperatures and overall light winds (afternoon
gusts up to 15 to 20 mph). Today and, especially, Thursday,
monsoon moisture works its way back into the area. Look for very
isolated mountain showers and dry thunderstorms by Thursday
afternoon (possibly this afternoon) with increasing storm
chances (but still isolated) by Friday afternoon. Friday will
likely be a more impactful day with the potential of lightning
starts with mostly dry storms. Storms sill look more wet and
widespread on Saturday and Sunday. &&

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

&&

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

&&

$$

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