059
FXUS65 KPIH 080259
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
859 PM MDT Mon Jul 7 2025
.KEY MESSAGES...
- Hot weather for the first half of the week.
- Cold front arrives Wednesday bringing cooler weather for late
week.
- Potential red flag conditions for wind and humidity Wednesday.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 135 PM MDT Mon Jul 7 2025
High pressure ridge continues to strengthen over the area today
allowing temps to continue their upward trajectory. Most lower
elevation spots have climbed into the 80s already with 90s
likely in the lower Snake and Magic Valley before daytime
heating is set and done. Afternoon satellite imagery is again
void of clouds for the most part although seeing a few extremely
isolated CU develop across the higher terrain and on the Idaho
border with Utah and Nevada. More of the same is expected for
tomorrow as H5 heights will pass 590+ DM and daytime highs top
out in the mid to upper 90s across the lower elevations. NBM
probs of hitting 100 are less than 30% across the Snake Plain,
Arco Desert and Magic Valley so it seems like the mid to upper
90s will be the sweet spot but can`t rule out someone hitting
100. Either way, it`s still hot. Hi-res CAMs are picking up on
some dry shower/storm activity developing across the central
mountains tomorrow so have added some PoPs in across these areas
accordingly. With PWATS less than half an inch, woudln`t expect
any precip to reach the ground but some gusty outflows and
lightning are certainly a possibility.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 135 PM MDT Mon Jul 7 2025
Wednesday looks very similar weather-wise, as far as temps are
concerned, although they may be one to two degrees cooler than
Tuesday. The bigger issue will be winds as a shortwave trough
approaches the area during the afternoon and evening hours. This
will tighten the pressure gradient over the region leading to
breezy conditions during the afternoon and evening hours
creating some fire weather concerns with very low RHs in place.
See fire weather discussion below for more details. Behind the
shortwave, temps look to cool closer to their normal levels for
mid July with mid to upper 80s likely on Thursday and Friday
while still remaining a touch breezy on Thursday as another
shortwave swings north of the area across the panhandle and into
Montana. As this feature departs to start the weekend, upper
level ridging once again builds over the region keeping things
dry and allowing temps to return back in to the lower to mid 90s
for the weekend. Things look dry throughout the extended aside
from maybe a mix of wet/dry thunderstorms in the central
mountains on Wednesday afternoon and evening. Otherwise, rain
chances look bleak through early next week, and beyond.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 858 PM
MDT Mon Jul 7 2025
We expect some mid level clouds around for the next 24 hours,
but look for VFR weather. At SUN, southerly winds again tomorrow
afternoon may approach thresholds to impact air traffic before
switching to southwest late in the afternoon. At the moment, we
COULD see some virga but little to no rain. There is a slightly
higher chance of a dry storm (10-20% AT BEST)in the central
mountains, but likely will stay well north of the airport.
&&
.FIRE WEATHER...
Issued at 135 PM MDT Mon Jul 7 2025
High pressure will peak Tue afternoon, pushing afternoon highs
to near records for Tue and Wed and plunge afternoon humidity
below 15 percent for widespread portions of the lower
elevations. A dry cold front sweeps through Wed night, but first
bringing stronger wind on Wed afternoon--enough to produce Red
Flag conditions for nearly all BLM lands, the southern Sawtooth
NF, and the Caribou portion of the Caribou-Targhee NF. It mostly
ranges in the 40 to 60 percent chance range for the gust
thresholds on DESI system predictions, so have issued a Fire
Weather Watch at this time. There has been an increase in the
thunderstorm coverage for Wed evening and overnight, but it is
not yet at scattered coverage. This, too, will have to be
monitored for its trend.
The dry cold front does have the benefit of bringing mild relief
from the heat and the afternoon humidity goes up starting Thu.
What it doesn`t help is overnight recovery is terrible in a
number of locations during this time. And the instability is
really strong each afternoon and early evening for Tue and Wed,
as evidenced by the very high mixing heights that are 9000ft or
more even in the Salmon-Challis mountains, never mind lower
elevations.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for IDZ410-413-425-427.
&&
$$
SHORT TERM...McKaughan
LONG TERM...McKaughan
AVIATION...Keyes
FIRE WEATHER...Messick
