Winter Weather Advisory 8, NWS Pocatello, ID

Area Forecast Discussion
National Weather Service Pocatello ID
421 AM MST Sat Feb 6 2021

.SHORT TERM...Today through Monday. Strong northwest flow will
remain through the period, especially today and Sunday. Snow has
currently backed off across the Eastern Highlands but another
wave this afternoon in northwest flow will start to bring snow for
the Sawtooths and, in particular, the Eastern Highlands where 5
to 10 inches of higher elevation snow is likely. A winter weather
advisory is in effect for the Wasatch mountains, Caribou
Highlands, and the Big Hole mountains for moderate snow and
blowing snow. Winds will be a factor/impact for our entire area.
Winds aloft will be around 50 to 55 mph. The best areas to mix
down and see gusts of 50 mph are the Snake River Plain and Eastern
Magic Valley, especially the I-84 corridor where a wind advisory
is in effect. Other areas will see gusts of 30 to 40 mph. An
Special Weather Statement will be issued where winds, existing
snow, and light falling snow will have the biggest impacts. These
will be mainly along the Utah Border and Wyoming border. The
biggest concerns for wind and blowing snow will be Yale, Sweetzer
Summit, Malad Summit, Georgetown Summit, Highway 33 from Rexburg
to Tetonia, and the Eastern portion of the Island Park area. Thus,
Special Weather Statements have been issued for these areas.

Sunday northwest flow will continue but only lingering very light
snow is expected mainly over the Island Park area. Winds will
still be breezy to moderate but should have much less impacts. By
Monday the winds will still be breezy but will be even lighter.
Little, if any, snow is expected by Monday. Temperatures will be
above normal today and Sunday mainly across our Southwest areas
where the wind will be the strongest. By Monday expect below
normal temperatures, especially in our northeast areas where cold
air is expected to work its way over the Montana Divide.
Wyatt

.LONG TERM...Tuesday through next Saturday. The general consensus is
that we will see an increasing chance of precipitation and
increasing winds. The questions remaining are: how and wet and how
cold. The GFS wants to swing a storm through later Wednesday and
Thursday, followed by a fairly dry but cold pattern. The 12z ECMWF
was wetter and colder, but now the ECMWF is trending warmer and even
more wet. There has been poor consistency and trends with the
pattern toward the middle and end of next week. The Blend of Models
is doing what it should be doing, showing a potential forecast of
all the models and the ensembles. That shows an increasing chance of
precipitation but much colder. With the huge lack of certainty, we
will go with the Blend of Models.
Keyes

&&

.AVIATION...We will see the next surge of moisture arriving later
today. The bulk of this (mainly in the form of snow) will fall
across the central mountains and eastern highlands. With northwest
flow, the snow SHOULD stay to the northwest of SUN. This certainly
favors DIJ, although we will need to watch conditions with a south
to southwest wind. The most likely scenario is MVFR weather, dipping
into IFR with heavier bursts of snow. At IDA and PIH, upslope flow
may produce light snow over the airports...but the most likely
scenario is the snow falls in the benches or even farther into the
mountains away from both sites. At BYI, we are not expecting any
issues other than gusty winds again today. In fact at BYI, PIH and
IDA...the biggest issue should be the winds with gusts of 25-35kts
expected.
Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 11 AM this morning to 9 PM MST this evening
for IDZ054-055.

Winter Weather Advisory from 11 AM this morning to 9 PM MST this
evening for IDZ060-063-064.

&&