600
FXUS65 KPIH 081932
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
132 PM MDT Tue Jul 8 2025

.KEY MESSAGES...

- Hot weather this afternoon and on Wednesday.

- Cold front arrives late Wednesday bringing slightly cooler
  weather for late week but returning to above normal temps for
  the weekend.

- Red flag conditions for wind and humidity Wednesday.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 130 PM MDT Tue Jul 8 2025

The heat is on across the region as temperatures have already
climbed well into the 90s across much of our lower elevation areas
this afternoon. They`ll continue to climb into the mid to upper 90s
before the day is over as high pressure remains in full control
today. Afternoon satellite imagery is beginning to show some slow CU
development across the central mountains and this area does appear
in line to see some isolated shower/thunderstorm development later
this afternoon and evening. Given the extremely dry airmass,
expecting these to be of the dry variety but will likely produce
some gusty outflow winds and maybe some lightning. Things look very
similar for tomorrow with temperatures within a degree or two of
today`s highs. The biggest difference will be the increase in winds
as a shortwave moves through the region. These winds combined with
hot temps and low RHs set the stage for Red Flag conditions on
Wednesday. For more info, see the fire weather discussion below. As
the shortwave moves through the region, it could spark some
showers/thunderstorms once again, but with a bit more areal coverage
potentially bringing chances to any part of the forecast area. They
will likely remain dry in nature so gusty winds and lightning will
be the greatest risk with them but some of these could potentially
linger into the overnight hours of early Thu AM.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 130 PM MDT Tue Jul 8 2025

Behind the shortwave, temperatures will cool 5-10 degrees for
daytime highs on Thursday and Friday with temps returning to the low
to mid 80s across the area. Winds will remain breezy on Thursday, 15-
25 mph, but the cooler temps and higher RHs should reduce the risk
of any Red Flag conditions being reached. Winds will back off as we
get into Friday as ridging once again builds over the area later in
the day and continuing into the weekend. As this occurs,
temperatures will begin to climb once again over the weekend into
the 90s across the lower elevations where they look to stay into at
least the first part of next week. Precip chances look bleak
Thursday into next week keeping the things very summer-like across
eastern Idaho.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1102 AM MDT Tue Jul 8 2025

A FEW-SCT altocumulus will start to move into southern Idaho
early this evening, but still not expecting any CIG even at
those altitudes. These mid-level clouds are in very unstable air
and there could be some isold TS with no precip in the mountains,
but right now it appears to stay well north of KSUN and KDIJ.
VSBY will continue unlimited. Wind is continuing light and
slope- valley effect mainly until approximately 09/15Z, when an
approaching cold front from the west will generate some
southerly breezy wind with even stronger wind by mid-afternoon.

&&

.FIRE WEATHER...
Issued at 130 PM MDT Tue Jul 8 2025

The expected upper level trough and dry cold front is still on
track to create some Red Flag conditions from mid-afternoon
into the evening. Hot afternoon temperatures will still drive
humidity into the single digits and low teens. The strong
heating has also been increasing the instability this afternoon
and again Wednesday afternoon, which has helped mix down
stronger wind from higher up in the atmosphere, with mixing
heights peaking tomorrow above 20000ft MSL, which is high even
for this time of year. Have upgraded the Fire Weather Watch to a
Red Flag Warning.

This dry cold front, with the continued high instability, will
trigger dry thunderstorms, mostly from early evening (1800 MDT)
and into the late night hours, rather than the afternoon. At
this time, as it has for the last three days, guidance has been
leaning towards probabilities below the 25 percent threshold,
except in the northern end of the Salmon-Challis NF; but they do
not have critical fuels there...yet.

This cold front provides 8 to 12 deg F of cooling and a similar
uptick in humidity percentages, both recovery and minimum. This
will last for Thu and Fri, then the upper level ridge reasserts
itself and afternoon highs soar back into the 90s and humidity
dries out, though not quite to pre-front levels. Will have to
monitor wind in the Snake River plain, as it will bring if not
push weather conditions into the critical thresholds for wind
and humidity.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 3 PM to 9 PM MDT Wednesday for IDZ410-
413-425-427.

&&

$$

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