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fxus65 kpih 162046 

Area forecast discussion
National Weather Service Pocatello Idaho
246 PM MDT Wed Oct 16 2019

Short through Friday night. Well above normal
temperatures will continue today as the high pressure ridge axis
moves east and southwest flow streams into our area ahead of the
next system. Some areas along the I-86 corridor will reach near
record temperatures with southerly downslope winds. The next
system is currently located off the British Columbia coast and
will bring a cold front through our area late Thursday into
Friday. Thursday expect breezy winds for the Snake River Plain and
ridge tops. Winds get slightly stronger Friday approaching near
Wind Advisory levels, mainly for the Snake River Plain with
strongest values in the Arco desert area. Expect snow starting
early Thursday afternoon for the western central mountains and
later Thursday afternoon for the eastern Highlands along the
Wyoming border. Friday the flow becomes more westerly with
continued light snow for the western slopes of the Sawtooths and
the eastern Highlands. Look for 1 to 4 inches of snow Thursday to
Friday, mainly above 6000 to 6500 feet with light rain below
these levels. Upslope areas in westerly flow for the Sawtooths and
eastern Highlands along the northern Wyoming border will see the
most snow. Wyatt

Long term...Saturday through next Wednesday. Models continue to
showing a significant winter system moving through our area
Saturday into Sunday. The 3 to 7 day hazard outlook from wpc
continues to highlight the central mountains and the northern
eastern Highlands along the Wyoming border for heavy snow.
Currently 8 to 12 inches of snow is expected for these areas
Saturday morning into Sunday morning. A winter weather warning may
be needed for our extreme northwest areas over the Sawtooths
including Stanley as well as the Big Holes and the Island Park
area. Driggs currently looks to receive 4 to 6 inches of snow but
there is guidance suggesting up to a foot of snow is possible.
Galena, targhee and the Jackson passes will receive significant
snow making driving hazardous. Winter weather advisories are
anticipated for almost all other mountain zones across the central
mountains and the eastern Highlands along the Wyoming border.
Snow levels will start around 6000 feet on Saturday and drop to
the valley floor by Sunday morning. However most of the valley
precipitation will be likely be over by Sunday morning. Elevations
around 5000 to 5500 will likely see slushy snow making driving
difficult late Saturday night into Sunday morning. Temperatures
will drop to around 5 to 10 degrees below normal on Saturday and
then drop slightly more to around 10 to 15 degrees below normal on

Sunday into Monday expect breezy northwest flow with continued
light snow over the extreme northwest central mountains and the
eastern Highlands. The GFS model has now changed for Wednesday
holding off the next system until Thursday. The European model (ecmwf) model still
shows this weaker system moving through next Wednesday. Currently
temperatures will approach near normal Monday and slightly above
normal on Tuesday. Wyatt


Aviation...afternoon gusty wind possible due to downslope wind
conditions this afternoon at kpih, otherwise light wind will prevail
at the other four airdromes. A cirrus shield is expected to arrive
during the late afternoon in the western airports, and during the
overnight hours for the three eastern-most. However, cigs do not
develop until sometime after 17/15z and before 17/18z, so right now
only ksun reflects this. So no impact to aviation operations until
Thu afternoon, and even then it is only slight. By early evening on
Thu, kdij will be the most affected; possibly kida, ksun. Messick


Pih watches/warnings/advisories...

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