780
FXUS65 KPIH 061937
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
137 PM MDT Sat Sep 6 2025

.KEY MESSAGES...

- Thunderstorm threat expands to everywhere by 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 133 PM MDT Sat Sep 6 2025

Afternoon satellite imagery shows continued hazy/smoky skies across
much of eastern Idaho but a thicker cloud deck and precipitation
moving in from the south is slowly pushing some of this smoke to the
north. This should continue over the course of the day but I`d
imagine we`ll still have a bit of lingering haze into the day
tomorrow despite the increased clouds and precipitation. Speaking of
the latter, hi-res models continue to show some scattered activity
moving throughout the region into the evening hours. Not expecting a
ton of precipitation from these, nor any real severe threat, but
some beneficial rainfall is always helpful. Do have to look out for
some lightning / fire starts and some occasional gusty winds from
these storms however. Should get a bit of a break from the precip
after midnight or so, although some lingering showers remain
possible in spots overnight, before another day of widespread
showers and storms look likely to round out the weekend tomorrow.
Temperatures both days look to run right around seasonal norms.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 133 PM MDT Sat Sep 6 2025

Models remain in excellent agreement early in the week regarding
inland shift of Pacific low. Most of Monday looks dry between
shortwaves, but next onset of showers and thunderstorms look to
arrive Monday night across the central mountains. The unsettled
pattern begins in earnest beyond that time as the trough axis
reaches the coast. Moisture continues to push into East Idaho around
the upper low, with series of shortwaves providing focus for
convection to develop. Ensemble clusters begin to show some
deviation beginning Wednesday particularly with the depth of the
trough as it shifts toward the Great Basin. Regardless of the
details, the general scenario remains the same. Upper low continues
to slowly track east through the week, ejecting in some manner to
the east or northeast by the weekend. Unsettled conditions with
continued cool temperatures are expected all week, trending toward
drier by Saturday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 133 PM MDT Sat Sep 6 2025

Smoke and haze look to slowly improve over the course of the day
although clouds and precip chances will be on the rise. As such,
have added some VCTS/PROB30s into the forecast to account for latest
thinking from hi-res model guidance. Gusty outflow winds will be
possible with any of the stronger storms but otherwise the synoptic
wind regime remains fairly light. Precip should taper off during the
evening hours but things look to remain active for the second half
of the weekend with another round of showers and storms expected on
Sunday. VFR expected to prevail through the period outside of some
brief, localized reductions associated with any convection.

&&

.FIRE WEATHER...
Issued at 133 PM MDT Sat Sep 6 2025

First round of moisture to impact the East Idaho fire districts
arrives today. Showers and a few weak thunderstorms already
developing across western and southern portions of the forecast
area. Storms will be primarily dry today though a few of the more
zesty storms may be able to produce a very localized wetting rain.
Model probabilities support a 30-40% chance of a wetting rain across
the northern and southern Sawtooth NF areas, and the Bear River
Range portion of the Caribou NF. Elsewhere, the chances drop off
significantly to 20% or less, especially to the northeast where
chances for thunder are much less.

A second shortwave pushes through on Sunday, but the threat for
thunderstorms moves to the northeast with lesser chances for the
southern zones.  The best chances for wetting rains moves
accordingly as well. Model probabilities for wetting rains support a
45-55% chance across all of Zone 411, the eastern half of Zone 476,
and the northern portion of Zone 410 mainly bordering 411. The rest
of the district supports a 10-25% chance of wetting rains for
Sunday.

Drier conditions arrive for Monday between systems, but timing of
the next feature may bring arrival to the central mountains Monday
night for showers and an isolated overnight thunderstorm. That will
begin a period of prolonged unsettled conditions through the
remainder of the week with isolated to scattered showers and
thunderstorms each day, cooler temperatures, and an early fall-like
feel to the humidities.

&&

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

&&

$$

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