Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 280141

Area Forecast Discussion
National Weather Service Cheyenne WY
641 PM MST Sun Nov 27 2016

Issued at 632 PM MST Sun Nov 27 2016

Updates this evening will mainly be to snow amounts and
Winter/High Wind headlines across southeast Wyoming. No changes
along and east of I-25 through Monday...except to remove POP
tonight due to downslope winds. Will likely have to end the Winter
Weather Advisory early across some of the lower elevations of
Carbon county since consistent snowfall has struggled to develop
outside of the mountains...and this latest band is not impacting
the lower elevations too much. Blizzard conditions still being
observed near Arlington...and expect these conditions to linger
tonight although some slight improvement is possible after
midnight according to the latest high resolution models. It
appears as the peak of the stronger winds is occurring right now
across the Laramie Range and adjacent will likely
expire this warning on time tonight with gusts between 45 to 58
MPH currently observed over this area.


.SHORT TERM...(This evening through Tuesday)
Issued at 225 PM MST Sun Nov 27 2016

Water vapor imagery showing first cyclonic circulation moving into
northeast Wyoming and western South Dakota this afternoon.
Another circulation can be seen back over west central Utah this
afternoon moving towards the east northeast. IR imagery showing
warp around moisture and cooling cloud tops remaining over most of
southeast Wyoming. Two surface lows being observed, one across
northeastern Wyoming and the other across northeastern COlorado
this afternoon. Winds are slowly on the increase. We saw 53MPH
gusts at Cooper Cove a little while ago. Bordeaux wind gusts are
steadily rising, up to 42 MPH with sustained winds in the mid 30s.
Across the Summit, mid 40 MPH gusts are common.

Strongest gradients are yet to come this afternoon and evening.
Latest WRKHGT product showing 68/63mtrs Craig to Casper 850/700mb
height gradients respectively after 00Z and this agrees with the
GFS high wind product as well. So for the time being, will let
current wind headlines go as they are.

Heaviest and most widespread snow to occur tonight as that
secondary low pressure system tracks across Carbon County. Going
to let current headlines ride at least through this secondary
disturbance to see if heavier snow and increased winds do develop.

After a brief break tonight, winds pick up again Monday towards
noon as 700mb winds increase behind the departure of that
secondary system. WRKHGT/WRGHT reflect this as well. Later shifts
may want to extend the wind prone area wind warnings to go through
the afternoon hours Monday.

.LONG TERM...(Tuesday night through Sunday)
Issued at 225 PM MST Sun Nov 27 2016

Wednesday through Friday looking pretty chilly as the region
remains under rather low thicknesses between two upper lows.
One will move across the Great Lakes region while a second drops
south over the western CONUS during the period. Lingering snow
showers associated with the first low will come to an end Tuesday
night over most of the CWA but some will likely persist over the
higher mtns through Weds due to orographic lift. A push of colder
air will arrive Tuesday night with a reinforcing surge anticipated
on Thursday. Little if any pcpn expected Thursday through Sunday
with weak upper support seen and rather dry air. Temperatures
should warm some next weekend as upper ridging builds over the


.AVIATION...(For the 18Z TAFS through 18Z Monday morning)
Issued at 1026 AM MST Sun Nov 27 2016

Mostly vfr conditions through the taf period except for KRWL where
some MVFR/IFR cigs expected by late this afternoon through tonight.
Strong west winds will develop this afternoon, with gusts to 30-45
kts at the southeast WY sites and gusts to 25-35 kts over the
Nebraska Panhandle. Winds will stay elevated through the night. Snow
showers are expected to develop this aftn around RWL and continue
into this evening.  Higher mtns frequently obscured.


Issued at 225 PM MST Sun Nov 27 2016

No fire weather concerns through the middle of next week. It will
be breezy to windy through Wednesday, however minimum afternoon
humidity values will mostly be above 30 percent with cold
temperatures in place.


WY...Winter Storm Warning until 5 AM MST Tuesday for WYZ112-114.

     Winter Weather Advisory until 5 PM MST Monday for WYZ109-111-113.

     Blizzard Warning until 5 PM MST Monday for WYZ110.

     High Wind Warning until 11 PM MST this evening for WYZ107-115-

     High Wind Warning until 2 PM MST Monday for WYZ106-116-117.



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