966
FXUS65 KPIH 161929
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
129 PM MDT Sat Aug 16 2025

.KEY MESSAGES...

- Near critical fire weather conditions will carry through
  Sunday with scattered thunderstorms and gusty winds

- Scattered thunderstorms could be strong, producing brief
  downpours and strong outflow winds

- Drier conditions will return for the bulk of the week with
  temperatures moving back above-normals

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 1239 PM MDT Sat Aug 16 2025

Beginning to see some vertical development in the cu fields over
the Southeast Highlands and Central ID mountains early this
afternoon. We should see these two areas favored for the afternoon
shower and thunderstorm development, similar to what we`ve seen
over the last several days. How far downstream thunderstorms are
able to propagate and develop remains to be seen, but at least
the Upper Snake Plain around the area of the Sand Creek Fire
should stand a decent shot at gusty thunderstorm winds and
perhaps brief downpours. With anywhere between 1000 and 1500
J/kg of dCAPE progged, any of these storms today will likely
produce gusty winds that could easily top 40 mph.

The daily forecast has been a bit of a rinse and repeat with
showers and thunderstorms developing in the afternoon,
dissipating in the evening with lingering virga overnight.
Tonight and Sunday will be no exception. After the showers and
thunderstorms today wane, we`ll see lingering moisture around
with some mix of clearing and clouds overnight. Sunday looks
similar, if not perhaps a little juicier in terms of moisture
content as the moisture stream inches closer to central Idaho.
One would expect the central ID mountains and eastern highlands
favored again for shower and thunderstorm development and that`s
just what near term ensembles show. HREF favoring the central ID
mountains for the best coverage of thunderstorms Sunday,
including producing some +40 mph gusts. Any of these
thunderstorms gusts could cause gusty and and erratic fire
weather conditions today and Sunday, so expect similar Red Flag
Warning conditions again for Sunday.

By Monday, we`ll begin to see the ridge of high pressure nosing
back westward leading to a drying and warming trend that will
hold into the long term.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Issued at 1239 PM MDT Sat Aug 16 2025

Ensembles remain in close agreement through the extended. East
Idaho remains between large trough off NW coast and
strengthening high pressure over the Four Corners early in the
week. Dry flow aloft contributes to increasing daytime highs,
lower humidities, and no precipitation. Highs Tuesday and
Wednesday look to be the warmest days, with temperatures jumping
well into the 90s, approaching upper 90s in some locations. NBM
probabilistic spreads still support a 5-15% chance of reaching
100 degrees across many lower elevation areas. By Wednesday and
Thursday, there are some hints that moisture could begin to
cycle around the high over the Four Corners region through the
Great Basin into East Idaho. Thunderstorm chances increase exist
Friday into next weekend, which would also help to cool off
daytime highs somewhat.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1139 AM MDT Sat Aug 16 2025

VFR conditions remain in place but moist airmass will allow for
isolated to scattered TS today. Latest high-res models continue to
show quite a bit of uncertainty for SUN, so left VCSH for the
afternoon, but maintained PROB30 TS for all other sites with gust
potential at least 40kts mainly between 21Z and 02Z. Another feature
lifts through the region overnight, with a very low confidence
chance of SHRA redeveloping after 06Z. The best chances of
precipitation associated with this feature remain well NW of SUN, so
will continue to leave out of forecast for now. Sunday
afternoon does appear to be a repeat of today, so expect
additional TS mention for after 18Z in upcoming issuances.

&&

.FIRE WEATHER...
Issued at 1239 PM MDT Sat Aug 16 2025

We`re in the midst of a fairly prolonged critical fire weather
period today. We`ve seen a slight increase in moisture over the
last day or two, but RH values will still be flirting with sub
15% this afternoon and evening under breezy conditions. The Red
Flag Warnings, however, were issued primarily for the scattered
thunderstorm threat we`re seeing develop again this afternoon.
Scattered thunderstorms are favoring two areas of development,
the central ID mountains (zones 475/476) and the eastern
highlands (zones 411/413). We`re expecting thunderstorms to
continue their development and downstream propagation into the
upper Snake Plain in the area of the Sand Creek Fire (northern
zone 410). Any area under or adjacent to thunderstorms this
afternoon will likely see gusty and erratic winds as dry air in
the mid levels can easily mix down.

Similar to last night, we`ll see downward trend in thunderstorm
strength and development into the overnight, although some
spotty gusts could remain with virga in the area. Sunday we`re
looking at a similar trend as today, but moisture increases ever
so slightly. This will limit min RH values to just above
critical thresholds, but similar to today, we`ll be looking at
additional Red Flag Warnings for most zones surrounding the
Snake Plain for the scattered thunderstorm potential. Those RFWs
will be issued again this evening/overnight as today`s are
allowed to expire. By Monday we`re seeing high pressure push
back westward and into the area, drying the atmosphere out and
limiting thunderstorm potential. We will, however, begin to see
temperatures creep back upward toward the middle of the week,
leading to very low RH values Mon/Tues/Weds.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for IDZ410-411-
413-475-476.

&&

$$

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