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000
FXUS65 KPIH 152051
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
251 PM MDT Mon Apr 15 2024

.SHORT TERM...Tonight through Tuesday night.
Showers and isoalted thunderstorms will occur this evening mainly
in the southern mountains and Snake River Plain and the eastern
highlands. Snow levels will be around 8 thousand feet. Windy
conditions will continue in the Southern Hills, Raft River region
and Eastern Magic Valley with gusts up to 40 to 45 mph with a wind
advisory in effect until 11 pm. The advisory will expire at 11 PM
with showers ending around midnight in the eastern regions.
Tuesday will be dry in the morning with a Canadian trof spreading
rain and snow showers mainly into the Centennial mountains after
noon with snow levels at about 7500 feet dropping to around 5
thousand feet overnight Tuesday night with up to an inch of snow
above 7 thousand feet overnight. Lows tonight in the 20s and 30s
and highs Tuesday near normal mainly in the 40s mountains and 50s
valleys. Winds in the Snake River Plain on Tuesday will be in the
20 to 30 mph sustained range with some locations near advisory
criteria but most staying below. There is a 20 to 30 percent
chance of widespread advisory criteria occurring.
GK

.LONG TERM...Wednesday through next Monday. Wednesday will be much
cooler, showery, and breezy across the entire area. The consensus is
the first "wave" dropping south will push far enough south to cool
us off with a decent shot of moisture over much of central/eastern
Idaho...but especially along the Divide. Light accumulations are
likely in the central mountains, eastern and southeast highlands. We
might even see a dusting around Rexburg and Mud Lake. Early numbers
show we might see 1-4" across the Teton Valley, Big Holes, and lower
elevations around Island Park. Upwards of 3-8" at or above pass
level around there is possible. There is a 15-25% chance of more
than 4" around Henry`s Lake and up to 60% across the higher
elevations along the Montana and Wyoming borders. Valley highs are
still trend cooler, with current forecasts showing 40-50"ish" across
the valleys. For Thursday, that first "wave" clears with another one
developing near the US/Canada border. We may see some showers later
in the day across the north in response to that...but it still
depends on how far this next "wave" drops before scooting off to the
east. All 3 operational models and the clusters are fairly
consistent with the current idea of this wave hanging a bit farther
now for the moment. We should warm a handful of degrees Thursday and
remain on the breezy side. Friday and Saturday continue to look
drier with a decent warm up each day. This is where the waters are a
bit more "muddy". Around 55% of the clusters hold enough of that
trough back along the US/Canada border to hold the ridge down and/or
keep it west a bit vs the rest of the clusters. The former fits the
ECMWF fairly well, while the latest GFS matches nothing and slams
the ridge farther east and already has the next low squashing it.
Beyond that is anyone`s guess. The latest ECMWF spins up a closed
low that slowly crosses the Panhandle and Montana. The GFS has a
closed, albeit faster moving storm along the US/Canada border that
eventually becomes an Alberta Clipper. Only 20-25% of the clusters
show any type of low/trough impacting us, while the rest have some
type of ridge overhead. Our Blend of Models has some showers around,
which seems plausible, but warming temperatures. Cooler
temperatures, especially Wednesday-Saturday mornings, will help out
with slowing down snowmelt and runoff a bit.  Keyes

 &&

.AVIATION...Showers with a few thunderstorms are expected through
this evening, but not long after midnight. IF we can get
thunderstorms, gusts of 25-35kts are possible along with a brief
burst of rain. Right now, the risk of storms at a particular airport
are low. Winds remain breezy outside of storms today, gusting 20-
30kts...except closer to 35-40kts at BYI where they are on the edge
of some stronger winds across the Magic Valley and South Hills.
Expect VFR weather except for some brief reductions with any heavier
showers or storms. We currently are not expecting any showers
tomorrow at any TAF sites, but the winds should be stronger from the
west and southwest...25-35kts.  The exceptions in these cases will
be SUN. For today, winds remain southerly through the morning...with
the expectation that they actually switch to the northwest early
this afternoon. We currently are going with 10-20kt winds, but some
of the higher resolution numbers are actually 5-10kts stronger. This
is definitely NOT typical at that airport. They should remain from
that direction, but lighter, tonight and Tuesday morning. We expect
the usual switch tomorrow afternoon, but ramping back up speed-wise.
Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 11 PM MDT this evening for IDZ055>057.

&&

$$