Area Forecast Discussion
Issued by NWS Pocatello, ID

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000
FXUS65 KPIH 192131
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
231 PM MST Sun Nov 19 2017

.SHORT TERM...Tonight through Tuesday night. Models have trended
upwards a little with the southwesterly stream of moisture from the
Pacific into Northern California and then on to the Southeast Idaho
mountains on Monday. This will increase forecast snow amounts in
the Central Mountains above 7500 feet elevation, primarily around
Galena Summit and Banner Summit, to 3 to 7 inches between noon
Monday and noon Tuesday. An advisory will be issued. Model consensus
also increases the amplitude of a weak ridge over this area Monday
night into Tuesday. For the rest of the mountain areas, 1 to 3
inches snow accumulation is expected above 6500 feet, along with
snow levels rising to 7500 to 8000 feet by Tuesday morning. The
Snake Plain may see some mixed rain and snow with little
accumulation Monday. RS

.LONG TERM...Thanksgiving through next Sunday. Thanksgiving looks
warmer and drier with high pressure over us. How warm? Try 10-20
degrees ABOVE AVERAGE! Lower valleys will be well into the 50s, with
higher elevations in the 40s. The only 30s for high temperatures
will likely be on the highest peaks and ridges. Any threat of
showers will be low and only in the central mountains and Upper
Snake Highlands. The chance for rain and mountain snow increases
Friday as a storm races east closer to the US/Canada border. This
will knock down the ridge a bit, bringing cooler air and snow levels
around 6500-7500 across the north and 8500-9000ft near the Utah
border. Precipitation amounts look light, with impacts minimal for
now in terms of travel. It will be breezy across the region as well.
For the rest of the holiday weekend, we will be stuck in southwest
flow and in between a developing low along the coast and the ridge
that rebuilds just to our east.  There still some lack of certainty
on if we will remain dry or see some rain or snow with moisture
pushing out ahead of the storm. We went with something in between
with pretty low chance daily focused over higher elevations. The
"cool-down" we are talking about isn`t really that much, only about
5-8 degrees which leaves everyone still ABOVE AVERAGE by a good
margin. Keyes

&&

.AVIATION...VFR weather continues into tonight. Clouds will begin
lowering  overnight and tomorrow from west to east.  We should see
snow begin at KSUN somewhere around 12-14z. For KBYI, we should a
potential for snow eventually mixing mixing with rain in the
morning. We included VCSH at KIDA, KPIH and KDIJ for mid to late
morning. Those sites will see the chance of rain (likely snow at
KDIJ) pick up between 18-20z. Look for ceilings and/or visibility to
lower to MVFR/IFR once precipitation begins. We will see gusty south
to southwest in places, peaking at 15-20kts sustained and gusts 25-
30kts.  Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from noon Monday to noon MST Tuesday for
IDZ031.

&&

$$



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