167
FXUS65 KPIH 150429
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1029 PM MDT Fri Aug 14 2026

.KEY MESSAGES...

- Burn Scar Flash Flood Risk: Deep monsoonal moisture across
  Eastern Idaho will support localized heavy rainfall and flash
  flooding today and Saturday. Flash Flood Watches remain active
  for the Wapiti and Big Rock burn scars today, with the Wapiti
  watch extending through Saturday.

- Active Saturday Storm System: Remnants of a West Coast upper-
  level trough will track through the region on Saturday,
  generating widespread showers and thunderstorms once again.

- Gradual Warm-Up and Mid-Week Drying: Unseasonably cool
  temperatures (highs in the 70s) will slowly moderate into
  early next week. A passing northern disturbance will keep
  storm chances elevated over the northern high country Monday
  and Tuesday before drier, seasonal conditions settle in mid-
  to-late week.

&&

.DISCUSSION...
Issued at 159 PM MDT Fri Aug 14 2026

Afternoon satellite imagery reveals partial clearing across the
region today, which has allowed surface temperatures to recover
slightly into the 70s across lower elevations. This solar
heating, combined with an entrenched plume of deep monsoonal
moisture, has initiated another round of showers and isolated
thunderstorms. While convective coverage will remain highest
across the Central Mountains and Eastern Highlands, scattered
showers and storms will also track across the Snake Plain into
the evening hours. High precipitable water values will make the
strongest cells capable of localized flash flooding, with recent
burn scars facing the highest vulnerability. A Flash Flood
Watch remains in effect for both the Wapiti and Big Rock burn
scars through this evening with the former location continuing
into the evening tomorrow. Convective activity is forecast to
diminish overnight before ramping back up toward daybreak
Saturday.

Atmospheric conditions will remain active on Saturday as the
remnant shortwave of a West Coast trough lifts northeastward
across Idaho. Model guidance continues to highlight the Central
Mountains for the most concentrated shower and thunderstorm
activity. Convective coverage elsewhere will be more scattered
as the upper-level flow transitions from southwesterly to
westerly, keeping the primary forcing mechanism aligned closer
to the northern terrain. Because deep moisture remains locked
in place over the Central Mountains, the threat of heavy
rainfall over the Wapiti burn scar remains high enough to
maintain the Flash Flood Watch on Saturday. Confidence in
organized thunderstorm coverage directly impacting the Big Rock
scar is lower at this time.

A transitional pattern begins Sunday as the primary monsoonal
moisture plume shifts eastward, offering a mostly dry finish to
the weekend for much of Eastern Idaho outside of isolated to
scattered central mountain showers and storms. Early next week,
a weak shortwave passing to our north on Monday and Tuesday
will maintain elevated precipitation chances from the Central
Mountains through the Island Park area, while locations further
south see only isolated coverage. Behind this wave, drier air
will build into the Intermountain West for the mid-to-late week
timeframe, suppressing widespread shower activity. Daytime
temperatures  currently running well below seasonal averages
due to cloud cover and rain  will steadily moderate through
early next week, returning close to normal levels by late next
week as the drier weather takes hold.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1025 PM MDT Fri Aug 14 2026

Trend has been for less and less cloudiness, with the only CIGs
below FL100 occurring with TSRA. TSRA still a factor on Saturday
afternoon. VCSH comments start occurring in the morning for some
locations, others like KSUN will wait until mid-day. Afternoon
and evening TSRA still limited to PROB30 category. Don`t see
much impact to VSBY as moisture appears to be decreasing. Wind
outside of TSRA outflow will continue light, staying at or below
10KT.

&&

.FIRE WEATHER...
Issued at 119 PM MDT Fri Aug 14 2026

The threat for showers and thunderstorms will continue this
afternoon and evening and continue Saturday as well. All
thunderstorms will be wet with the potential for wetting rains
under stronger thunderstorms. Potential wind gusts over 30 mph
as well near any outflow. Coverage decreases Sunday and expect
some drying next week as an upper level ridge tries to build in
once again. The driest conditions expected to be next week
Wednesday through Friday. At least isolated showers and
thunderstorms continue through Tuesday. Temperatures again rise
to warmer than normal by late next week as well after the recent
cooler conditions which will exist through the weekend into
early next week.

&&

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

&&

$$

DISCUSSION...McKaughan
AVIATION...Messick
FIRE WEATHER...GK