American Falls, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

316
FXUS65 KPIH 151722
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1122 AM MDT Fri Aug 15 2025

.KEY MESSAGES...

- Near critical to critical fire weather conditions will
  continue through the weekend due to gusty winds, low relative
  humidity, and isolated to scattered thunderstorms.

- Daily shower and thunderstorm chances will continue through
  Sunday, peaking in coverage each afternoon, with stronger
  activity capable of producing gusty outflow winds.

- Temperatures through next week will remain near normal to
  above normal with highs in the 80s/90s, peaking next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 235 AM MDT Fri Aug 15 2025

Early morning satellite imagery shows a shortwave trough
lifting northeast out of the Great Basin into eastern Idaho,
leading to very isolated showers as clouds continue to lift
northeast out of Nevada and Utah. This shortwave will help to
support another round of isolated to scattered showers and
thunderstorms this afternoon through the early evening hours.
Best thunderstorm coverage will remain confined to the Snake
River Plain, eastern Magic Valley, and Southern/Eastern
Highlands where the HREF model probability of thunder shows a
30-80% chance, highest along the Snake River south and east
towards Utah and Wyoming. Given a very dry environment in place,
stronger showers/storms and outflow boundaries will be capable
of producing wind gusts up to 55 mph (locally higher up to 65
mph) and areas of blowing dust. In that aforementioned most
active thunderstorm corridor, the HREF model probability of wind
gusts greater than 35 mph shows a 50-90% chance, indicative of
the strong outflow wind potential today. Highs today will remain
similar to Thursday in the mid 80s to low 90s with synoptic
winds outside of thunderstorm activity peaking this afternoon
around 10-25 mph with gusts to 20-40 mph.

Following that departing shortwave trough over the Continental
Divide tonight into Saturday morning, yet another short will
work northeast out of Nevada and Utah, supporting another round
of isolated to scattered showers and thunderstorms during the
afternoon and early evening hours. The primary difference
however with storms on Saturday will be a regionwide expansion
to include at least the mention of isolated activity across all
of central and eastern Idaho. Like the past several days, gusty
outflow winds will be the primary concern with stronger
activity, with gusts up to 50-55 mph possible. Highs on Saturday
will hold steady in the mid 80s to low 90s as synoptic winds
outside of thunderstorm activity remain breezy, peaking in the
afternoon around 10-25 mph with gusts to 20-40 mph.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 235 AM MDT Fri Aug 15 2025

Troughing over the West Coast will keep Eastern Idaho in
southwesterly flow aloft on Sunday and bring about a chance for
scattered showers and thunderstorms for many. Most of the
precipitation will remain in the higher elevations of the
Central Mountains, South Hills, and Eastern Highlands, but the
potential for a shower or storm will exist throughout all of our
CWA. One would surmise that with this rain and storm chance and
increasing cloud cover that temperatures would be a bit cooler
on Sunday and while they technically will be, we are still
looking at highs in the mid to upper 80s for most.

As we start next week, high pressure begins to build back in
over the Four Corners region and brings back dry conditions for
our area and a warming trend, as well. Highs will quickly return
to the low to mid 90s by Tuesday and stay there for Wednesday,
Thursday, and Friday afternoons. Winds won`t be too breezy next
week, but look to be in the 15 to 25 mph range each day.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1122 AM MDT Fri Aug 15 2025

VFR conditions look to continue across E Idaho through Saturday
morning. Isolated to widely scattered showers and thunderstorms
expected this afternoon, primarily impacting BYI, PIH, IDA and DIJ.
SUN looks to be too far northwest to see much activity today.
Maintained all PROB30 groups from previous forecast issuance, with
timing still expected to peak between 20Z and 02Z. Latest high-res
model solutions still producing gusts over 40kts. High clouds linger
overnight (10-12kft heights), and would not be surprised to see
pockets of virga around/after sunrise Saturday morning. Additional
thunderstorm development expected Saturday afternoon, but confidence
isn`t quite there for SUN yet so left out of terminal for now.


&&

.FIRE WEATHER...
Issued at 235 AM MDT Fri Aug 15 2025

Red Flag Warnings continue once again. Today, they are a bit
more limited in coverage to generally the South Hills and
Southeastern Highlands, which are our Fire Weather Zones 413 and
427, for scattered thunderstorms this afternoon. These storms
will be capable of producing wind gusts of 55 to 60 mph with
some isolated higher gusts closer to 65 mph. Outside of this
thunderstorm activity, it will still be very dry with afternoon
RHs ranging from 10 to 20 percent with wind gusts of 20 to 30
mph. We will likely see some portions of Zones 410, 475, and 476
reach Red Flag Warning criteria this afternoon. At this point,
coverage may be limited enough to not add these zones to the
RFW. However, will pass this concern along to the day shift in
case adjustments are needed. Either way, be prepared for near-
critical fire weather conditions for these zones.

On Saturday, min RHs finally begin to increase just slightly,
with at least more of us in the 15 to 20 percent range with wind
gusts very gradually decreasing a bit to the 20 to 25 range for
most. As more moisture arrives on Sunday, min RHs will jump
into the 30 to 40 percent range in much of the Central Mountains
and 15 to 25 percent range elsewhere. However, thunderstorm
activity will be nearly scattered across all of Eastern Idaho,
so Saturday may be the lone day of a very short break in our Red
Flag Warnings.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for IDZ413-427.

&&

$$

SHORT TERM...MacKay
LONG TERM...AMM
AVIATION...DMH
FIRE WEATHER...AMM