Area Forecast Discussion
Issued by NWS Pocatello, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
FXUS65 KPIH 270448

Area Forecast Discussion
National Weather Service Pocatello ID
948 PM MST Mon Feb 26 2024


Planning on issuing the second update around 530Z. Will allow
headlines in the eastern highlands to expire. Trends overnight
look good for winds continuing to diminish. HRRR is picking up on
this convergence band near Rexburg. That should move off towards
the Tetons over the next 3 to 4 hours. This is a relatively narrow
band of snow, but could potentially dump an additional couple of
inches in snow around Driggs. With that said, most of the
widespread snow across the southeast highlands should end soon.
So, long story short, intend to expire the warnings around 530z.



.PREV DISCUSSION... /issued 449 PM MST Mon Feb 26 2024/


First of two planned updates. Allowed the winter headlines for the
central mountains to expire as radar shows most of the activity is
now in eastern Idaho. Also allowed wind advisory to expire or
canceled remaining segments as winds have fallen off in most
places. A little concerned that the south hills could still have
some impressive gusts this evening, especially around Yale and
Sweetzer Summit. The HREF is signaling this. But those look like
isolated areas if those winds materialize. Second update later
this evening will deal with the headlines across the eastern
highlands. We`ve had numerous road closures across the Island
Park/Ashton/Driggs area so far.


PREV DISCUSSION... /issued 207 PM MST Mon Feb 26 2024/

A widespread mixed bag of rain, snow, and strong winds will continue
into this eve, with a few embedded snow squalls still possible
between 3 PM and 8 PM from Shoshone and Idaho Falls south to the UT
border. Wind gusts over 55 MPH and brief whiteout conditions will be
possible with the stronger snow squalls...we`ll be covering these
hazards with short-fused Snow Squall Warnings and/or Special Weather
Statements as needed. Also watching increasing blowing snow issues
in a few spots between I-15 and the WY border, especially NW of the
Teton Valley right now. No changes made to broader ongoing warnings
and advisories, and we should be able to trim them back
progressively into this eve as scheduled as everything settles down
from NW to SE behind the cold front. Stronger winds may continue
overnight and throughout Tue across the ern Magic Valley, lower
Snake Plain, and Raft River region, with some potential for the Wind
Advisory to be extended or reissued for these areas. Otherwise,
expect much lighter, more isolated snow shower activity to linger
tonight and Tue behind the main event...for many it will feel like a
bit of a break, although still a bit breezy. High temps Tue will
only top out in the 20s to very low 30s for most...about 10-15
degrees colder than today. 01

Our next storm will be a multi-day event, however we do expect
things to slowly progress at first. For Wednesday into the first
half of Thursday, we will see moisture increasing in southwest
flow across mainly the central mountains (specifically the
Sawtooths/surrounding ranges) and around Island Park. There is
general agreement between the extended models, clusters and our
Blend of Models. The only "disagreement" is strength of the
ridging ahead of the low. The Blend and about 75% of the clusters
are not as strong as the operational GFS and ECMWF. Even if this
turns out to the be the case, the focus will across those areas
mentioned in our prior thought. As the low digs and strengthens
closer to the coast on Friday, the models, clusters and Blend come
into very good agreement on everything. They fall out of
agreement again by Saturday, as each idea shows a different
evolution with the low weakening and shifting inland. The overall
theme with this event will be initially higher snow levels until
the front moves through going into Friday. That does mean the
potential mostly rain at lowest elevations and rain or rain/snow
mix at low/mid slopes of the mountains, and snow at highest
elevations. We will see snow levels quickly dropping with the
front later Friday and Saturday. By the time we get into Saturday,
it is likely we will see multiple FEET of snow in the higher
elevations(total accumulations over a 3-4 day period)...especially
the Sawtooths/surrounding ranges, Big Holes/Tetons and Bear River
Range. With this being a warm storm, that will plenty of "water"
in that snow. Lingering showers will persist Sunday and Monday.

Flying through this evening will likely be an adventure, as we
will have conditions continue to deteriorate during the
afternoon...but quickly clearing up this evening. The exception
with be DIJ as showers and potential convergence band will keep
conditions at least MVFR overnight and tomorrow morning. Before
that, all TAF sites will end up dropping to IFR due to ceilings
and/or visibility. There will likely small windows at LIFR as
well, and we are trying to cover with TEMPO groups at each TAF
site. Of particular concern is the potential for snow squalls with
gusts near or above 50kts later this afternoon and until the main
front clears the area this evening. There is a small potential
for even thunderstorms until that point as well, but for now we
didn`t include in the TAFs as we aren`t seeing much evidence
upstream...yet. Other than DIJ, except slow improvement in
ceilings and visibility for tonight and tomorrow
morning...although strong westerly winds will continue except at
SUN. Keyes


Winter Storm Warning until 11 PM MST this evening for IDZ060>066.


$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.