942
FXUS65 KPIH 140451
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1051 PM MDT Wed Aug 13 2025

.KEY MESSAGES...

- Temperatures "cool" off a bit, but still at or above average

- Critical to near critical fire weather conditions through the
  weekend

- Shower and thunderstorm chances persist for several day with
  gusty winds being the main risk

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 139 PM MDT Wed Aug 13
2025

As expected, we are seeing showers and thunderstorms developing
especially closer to the Utah border. The best chance of storms
through about sunset will be from Mackay to Gilmore Summit, the
eastern highlands, the Snake Plain north of Idaho Falls, and the
mountains along the Utah border. There is a 30-70% chance of
outflow winds over 35 mph where storms develop, with gusts over
45 mph expected with stronger storms. There is a low risk of
gusts over 60 mph across the mountains near the Utah border.
Rainfall will be rather scarce, but some storms will produce a
couple of hundredths in a rain gauge. Gusty winds OUTSIDE of
storms are on the increase, and will continue into this evening
as well. Gusts of 25-35 mph will be common, peaking closer to 40
mph across the Arco Desert. For tonight, a few showers
and storms will persist generally south of the Snake Plain. A
second band should form from around Mackay into the eastern
highlands. Overnight activity won`t have much lightning with it,
BUT enough to mention it in the forecast...as we should have a
similar situation as this morning. Expect a repeat tomorrow
across the area, although gusts will be slightly lower, 20-35
mph and locally higher across the Arco Desert. In terms of
outflow winds, the similar is basically identical to today and
in the same general locations. We should see a small break in
storms tomorrow night, with another round of storm across the
South Hills/Albion Mountains and southeast highlands. A few
storms may form elsewhere, but the chance is less than 10% at
the moment. Gusty winds OUTSIDE of storms should be confined to
the Snake Plain, eastern highlands, and central mountains.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 405 PM MDT Wed Aug 13 2025

We return to a bit more active pattern (comparatively) in the
extended forecast period due to a broad area of troughing over
the West Coast and an approaching closed low that arrives off
the coast of British Columbia late in the weekend. This will at
least keep a series of shortwaves passing through Eastern Idaho
to keep at least a mention of isolated to nearly scattered
showers and thunderstorms in our area each afternoon through the
weekend and into early next week though Sunday looks to be
about the peak of the activity, or at least the day with the
most widespread activity. This will help bring down our
afternoon temperatures a few degrees, so look for highs in the
upper 80s to low 90s in the lower elevations this weekend and
and very slight warming trend early next week as we begin to get
drier again as high pressure builds in over the Four Corners
Region. Wind gusts through the weekend will be around 15 to 25
mph.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1051 PM MDT Wed Aug 13 2025

Synoptic winds will be just a touch lighter Thursday as compared to
today, with gusts to around 25 kts. Another round of isolated to
scattered thunderstorms will return during the afternoon and evening
hours. Similarly to today, HREF indicates maximum gusts across much
of the area reaching 40 kts with stronger storms capable of 40 to 50
kt gusts. HREF probability of thunder is 20 to 30 percent at KDIJ
and KBYI between the hours of 22z and 03z. Have included PROB30s for
both terminals to account for peak convection. Elsewhere,
probability of thunderstorms is less than 20 percent and therefore
have included VCSH for this same rough timeframe.

&&

.FIRE WEATHER...
Issued at 139 PM MDT Wed Aug 13 2025

Active critical fire weather conditions continue this afternoon,
and appear to continue over portions of our area through the
weekend. All of our RED FLAG WARNINGS for today remain in effect
until 10pm for ALL ZONES. We had isolated storms earlier and see
more develop this afternoon. Coverage remains isolated but
pushing into scattered around Island Park and along our southern
border. There is still a 30-70% of gusts over 35 mph, with
stronger storms pushing over 45 mph. Storms south the Snake
Plain and Magic Valley still may produce winds closer to 60 mph
through sunset. OUTSIDE of storms, gusts of 25-35 mph are likely
with some gusts closer 40 over the central mountains and in the
Arco Desert. Overnight, we are looking for isolated showers and
storms to persist across Zones 413 and 427, with a second band
developing from around Mackay to Island Park. Similar to last
night, lightning will be fairly isolated but enough to keep in
the forecast. Tomorrow looks very similar to today in terms of
where storms will develop and coverage-wise. We may see a few
less storms across the Snake Plain in the afternoon. Similar
probabilities for gusts over 35 mph are forecast. Winds outside
of storms will be a bit weaker, especially across Zones 413 and
427. That said, we will be issuing RED FLAG WARNINGS for all
zones EXCEPT 422 and 425 for tomorrow afternoon and evening
(410/475 for winds and humidity only; 411/476 for winds,
humidity and isolated storms; and 413/427 for scattered
thunderstorms.) Beyond that, we will need tweak the forecast
based on trends to see when and where additional headlines will
be needed. We do expect persistent issues with winds, low
humidity and thunderstorm chances SOMEWHERE in central and
eastern Idaho through at least the weekend. Something that may
be in our favor will be some increase in humidity, but likely
not enough in some areas to alleviate any fire concerns...even
if it remains high enough to not factor into any warnings.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 10 PM MDT Thursday for IDZ410-
411-413-427-475-476.

&&

$$

SHORT TERM...Keyes
LONG TERM...AMM
AVIATION...Cropp
FIRE WEATHER...Keyes