602
FXUS65 KPIH 262040 CCA
AFDPIH

Area Forecast Discussion...CORRECTED
National Weather Service Pocatello ID
240 PM MDT Wed Jun 26 2024

.SHORT TERM...Today and Thursday.
Looking at current water vapor imagery, our area is under high
pressure in southwest flow aloft with the ridge axis just east of
our area. There is an upper level low just off the Washington
coast with broad troughing extending off this low just off the
Oregon and California coasts.

We have lingering scattered showers and isolated thunderstorms
over our area currently mainly across the Eastern Magic valley,
Snake Plain, and the Montana Divide from a warm front. There is
partial clearing across our area currently, which will aide to
instability of 400 to 800 J/kg of forecasted CAPE. This
instability coupled with 25-35 kts of 0-6 km shear and 0.70-1.00"
PWATS will support scattered to numerous showers and scattered
thunderstorms this afternoon into early evening. The HREF model
continues to show a 50 to 80 percent chance of thunderstorms this
afternoon into early evening. The HREF model continues to show the
majority of our western areas with a 90 percent chance of
receiving max winds from thunderstorm outflows of greater than 30
kts. Stronger thunderstorms today (from 2 pm to 10 pm) will be
capable of producing wind gusts in excess of 40 to 50 mph, small
hail, and brief moderate to heavy rain.

Thursday the upper level trough and associated cold front will
move through our area. Models continue to show scattered showers
and thunderstorms mainly along our extreme eastern areas along the
Wyoming border Thursday afternoon. The bigger impact Thursday
afternoon continues to be the wind. The 700 mb jet continues to be
around 30 to 45 kt. With good mixing Thursday afternoon, expect
sustained winds Thursday afternoon of around 25 to 45 mph with
wind gusts of around 35 to 60 mph. Currently there is a 10 to 20
percent chance of 60 mph winds from the NBM model north and west
of Idaho Falls. There is a 30 to 70 percent chance of 50 mph wind
gusts north and west of Idaho Falls Thursday afternoon. Plus,
there is a 60 to 95 percent chance of 40 mph wind gusts from the
NBM model for the Upper and Lower Snake Plain, Arco Desert, and
the Beaverhead Highlands. A wind advisory is in place for these
areas. High pressure ridging builds in Thursday evening bringing
cooler and drier conditions. Temperatures will be around 8 to 12
degrees above normal today before dropping to near normal to
slightly below normal by Thursday.
TW

.LONG TERM...Friday through next Wednesday.
It`ll be a "quiet" start to the extended forecast for Friday and
Saturday. Highs on Friday range from mid to upper 70s through the
Snake Plain with low to mid 70s elsewhere, but the heat is back on
again for Saturday as highs approach the mid 90s in the eastern
Magic Valley and lower Snake Plain thanks to a transient ridge of
high pressure moving over the area. The upper Snake Plain will be in
the mid 80s and low to mid 80s in the higher elevations. Troughing
moves in behind this ridge on Sunday and into Monday which will
bring chances for showers and storms once again and breezy winds.
This system will drop our highs by about 5 degrees from Saturday
followed by another 5 to 10 degree drop from Sunday to Monday,
meaning most highs will be in the 70s to low 80s on Monday
afternoon. The warming and drying trend gets underway after Monday
as we head through Tuesday and Wednesday towards the July 4th
holiday.
AMM

&&

.AVIATION...
18Z Wednesday through 18Z Thursday.
Main aviation impacts today will come from showers and thunderstorms
across the area. Any storm that passes over a terminal will be
capable of dropping VIS and CIGs to at least MVFR if not IFR and
produce small hail, quick downpours, and strong wind gusts around 35
to 45 kts. While previous model runs were wrapping up the activity
by midnight, latest model data suggest storms could linger about an
hour or two later. A cold front passing through on Thursday will
bring an isolated storm or two near DIJ and IDA, but the rest of our
sites are expected to stay dry. However, strong wind gusts will
impact everyone. Gusts will range from 30 to 40 kts at DIJ, PIH, and
IDA with the strongest gusts near IDA. It will still be breezy at
SUN, though closer to 25 kts. Quieter weather returns for Friday.
AMM

&&

.FIRE WEATHER...
Breezy conditions and a mix of wet and dry storms continue through
the afternoon and into the evening. Storms will be capable of
producing 45 to 50+ mph wind gusts, small hail, and brief downpours.
A cold front associated with a Pacific trough moving onshore will
arrive tomorrow as the system moves eastward. This front will bring
strong winds for Thursday and much drier and cooler air to us. Wind
gusts through FWZ 410 will range from generally 45 to 50 mph. These
will be the strongest wind gusts on Thursday, but even outside of
410, gusts will range from 40 to 45 mph throughout the Snake Plain
and 30 to 40 mph everywhere else. These winds in FWZ 410 in
combination with min RHs ranging from 13 to 20 percent will create
critical fire conditions. However, fuels are not yet critical
(though it has been noted that soil moisture is already quite dry)
so no Red Flag Warning has issued. Min RHs will be low for everyone
with values ranging from 15 to 25 throughout the rest of eastern
Idaho. The highest min RHs will be near 30 percent around the Bear
Lake area. Friday and Saturday will be dry days in every sense of
the word before our next system arrives on Sunday which will nearly
be a repeat of today.
AMM

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 9 AM to 9 PM MDT Thursday for IDZ052>054-067.

&&

$$