Area Forecast Discussion
Issued by NWS Cheyenne, WY

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478
FXUS65 KCYS 221159
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
459 AM MST Mon Jan 22 2018

.SHORT TERM...(Today through Tuesday Night)
Issued at 458 AM MST Mon Jan 22 2018

Main concern today will center on blowing snow potential as winds
increase today across much of the area. Wind gusts this morning
have held generally in the 25-40 mph range across southeast
Wyoming, with lesser values observed across the western Nebraska
Panhandle. Although significant drifting snow is impacting travel
on rural roads, visibilities have yet to be reduced significantly
per WYDOT RWIS sensors and webcams. Short range models prog KCAG-
KCPR LLVL heights increase to between 40-50 meters by around 18z
today. Winds will increase as a result, with wind gusts of 40-55
mph expected especially during peak of mixing between 10A-3P.
This will certainly produce areas of reduced visibilities in
blowing and drifting snow. Local ground blizzards will be a
possibility as well, especially near Arlington & Bordeaux around
that midday hour. Because no precipitation is involved today,
opted to change the highlight to a Winter Weather Advisory for
blowing snow at Arlington, over the I80 Summit, as well as in the
Bordeaux area. Trends will need to be monitored closely for the
potential for a Blizzard Warning should conditions warrant. Winds
will decrease late this afternoon and tonight, but remain
somewhat breezy.

Otherwise, skies will be mostly sunny today, as yesterday`s system
departs. Highs will climb back to near freezing east of the
mountains, and hold in the 20s west.

Fast-moving shortwave embedded within northwest flow will bring a
quick-shot of mountain snow later tonight. A quick 2-4" of snow
can be expected over the Snowy/Sierra Madres. Otherwise, Tuesday
will be dry, with high temperatures again reaching the low-mid 30s
at most locations.

Winds will begin to increase once again Tuesday Night and
Wednesday morning as KCAG-KCPR low-level height gradients once
again increase towards 50-60 meters. Will need to keep an eye on
this period as potential our next period of high wind potential.
For now, have increased winds to just below criteria as a result..

.LONG TERM...(Wednesday through Sunday)
Issued at 458 AM MST Mon Jan 22 2018

High wind potential continues across the southeast Wyoming Wind
corridor into Wednesday. Otherwise, a transitory ridge will build
keeping conditions and temperatures warming into the 40s for
Wednesday and Thursday. Both the GFS/ECMWF have trended weaker
for the progressive late week system, mainly just targeting the
higher terrain Thursday night and Friday. Nonetheless, several
inches of accumulation will be possible mainly over the Snowy,
Sierra Madre, and northern Laramie Ranges. Cold fropa will cool us
back into the 30s for Friday and Saturday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 458 AM MST Mon Jan 22 2018

VFR all airports next 24 hours. No issues expected.

&&

.FIRE WEATHER...
Issued at 458 AM MST Mon Jan 22 2018

No fire weather concerns today as widespread snow fell across the
region yesterday. Breezy to locally windy conditions will produce
areas of blowing and drifting snow. Temperatures warm back into
the 40s for Wednesday and Thursday, with the next chance of snow
returning to the mountains Thursday night and Friday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 2 PM MST this afternoon for WYZ106-
     110-116-117.

NE...None.
&&

$$

SHORT TERM...CAH
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...CAH



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