Area Forecast Discussion
Issued by NWS Cheyenne, WY

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218
FXUS65 KCYS 190953
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
253 AM MST Thu Jan 19 2017

.SHORT TERM...(Today through Saturday)
Issued at 253 AM MST Thu Jan 19 2017

Gusty winds around Bordeaux have eased some early this morning as
the pressure gradient has relaxed. The gradient should stay rather
low over the next couple days so do not expect the stronger winds
to return. Looks like another mild day across the CWA today as
the area resides under a narrow upper ridge with skies mostly
clear...though some increase in clouds should occur out west.
Clouds will increase across the CWA tonight as an upper trough
moves from the sw CONUS eastward across the central Rockys late
tonight and Friday. This will bring some snow showers to mainly
the higher mtns mainly late tonight into early Friday with about
2-5 inches accumulation. It will also push a modest Pacific front
across the CWA and cool max temps about 4-8 degrees for Friday.
Mainly dry Friday night and Saturday with seasonable temperatures.
A few snow showers still possible primarily over the higher mtns.

.LONG TERM...(Saturday night through Thursday)
Issued at 253 AM MST Thu Jan 19 2017

00Z model guidance remains quite similar to previous runs, but
with better agreement early next week. To start, a shortwave
trough will move overhead through Saturday night, followed by an
upper ridge. Light snow in the mountains associated with the
trough on Saturday night will end by sunrise, giving way to dry
conditions on Sunday. This will be short-lived though as a strong
Pacific jet moves overhead late Sunday. Vort energy within this
flow will enhance orographic snow Sunday night through Monday,
with models hinting at a few rain/snow showers across the plains
Monday with the combination of upper forcing and sfc convergence
on the northern fringe of a developing sfc low in eastern
Colorado. 00Z models, including GEFS mean, suggest a solution that
features a rapidly strengthening low over the central plains
Monday night through Tuesday, with our forecast area on the
western fringe of strong QG forcing and wraparound moisture.
Therefore, we may see snow continue through Tuesday, especially
across the plains, and bumped up PoPs for these locations due to
model congruence. However, kept values within reason as there is
still plenty of time for models to change. Northerly upper level
flow will then move into the western CONUS in the wake of this
system, maintaining cold conditions Wednesday and Thursday. A few
snow showers are possible through this time as models hint at weak
disturbances moving across the area.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1050 PM MST Wed Jan 18 2017

Breezy westerly winds are anticipated tonight at KCYS with gusts
around 20 kts. Similar conditions are possible Thursday afternoon
at KRWL, otherwise light winds will occur elsewhere. Still looking
at prevailing VFR conditions through much of Thursday, with
perhaps lowering cigs at KRWL starting late Thursday evening.

&&

.FIRE WEATHER...
Issued at 253 AM MST Thu Jan 19 2017

No concerns seen through the weekend with weather conditions
mostly non-critical and fuels generally moist.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

$$

SHORT TERM...RE
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...RE



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