Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 150001

Area Forecast Discussion
National Weather Service Cheyenne WY
458 PM MST Tue Nov 14 2017

.SHORT TERM...(This evening through Thursday night)
Issued at 200 PM MST Tue Nov 14 2017

Tonight...Shortwave trough aloft moves off to our east with clearing
skies overnight as surface high pressure builds in behind the
passing cold front. Should be dry with lack of low and mid level
moisture and lift.

Wednesday...Cooler in the wake of the cold frontal passage with 700
mb temperatures near 1 Celsius yielding high temperatures in the
upper 40s to mid 50s. Continued dry with lack of low and mid level

Wednesday night...Not as cool as the airmass moderates and with
increased low level winds.

Thursday...Warmer and windy as height and thicknesses continue to
rise. With increased low and mid level winds and gradients, our wind
prone locations may approach or exceed high wind criteria in the
afternoon. In the afternoon, expect a chance of rain showers, with
mountains snow showers across Carbon County.

Thursday night...A decent batch of low and mid level moisture moves
across our western counties along the baroclinic band, producing
scattered to numerous showers of rain and snow along and west of a
Douglas to Laramie line, dry elsewhere.

.LONG TERM...(Friday through Tuesday)
Issued at 200 PM MST Tue Nov 14 2017

Forecast concerns early in extended period will focus on winds
and high elevation snowfall.

Minor differences between the operational and ensemble medium range
model guidance. Very windy conditions will continue Friday with the
passage of strong cold front and upper trough. Westerly winds will
gust 35 to 50 mph over much of southeast WY. Friday will be much
cooler with highs from the mid 30s west to mid 50s east. Snow levels
will drop from 8000 to 6000 feet Friday. Strong westerly upslope
favors moderate to heavy snowfall above 8000 feet, with several
inches possible for the Snowy/Sierra Madre ranges. Blowing/drifting
snow will create hazardous travel, especially along I-80 between
Rawlins and Laramie. Rain showers will change to snow showers east
of I-25 early Friday evening before tapering off late. It will remain
breezy and cool Saturday followed by a gradual warmup Sunday and
Monday with the passage of a upper ridge. A weaker Pacific front
and shortwave trough passage Monday night and Tuesday will bring
slightly cooler temperatures and scattered rain/snow showers along
and west of the laramie Range.


.AVIATION...(For the 00Z TAFS through Wednesday afternoon)

Gusty west to northwest winds will continue into late this evening,
especially across the southeast Wyoming terminals.  Winds will
gradually diminish through midnight tonight.  Otherwise, VFR
conditions are expected.


Issued at 200 PM MST Tue Nov 14 2017

Minimal concerns based on expected winds and humidities.




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