Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 020412

Area Forecast Discussion
National Weather Service Denver/Boulder CO
912 PM MST Thu Dec 1 2016

Issued at 845 PM MST Thu Dec 1 2016

Trend in the developing pcpn from west to east appears slower
based of the latest HRRR mdls. Have trended the zones in that
direction. Most the qpf in the mdls runs keeps the developing snow
showers southwest and south of Denver through 18z Friday.


.SHORT TERM...(This evening through Friday)
Issued at 309 PM MST Thu Dec 1 2016

Satellite showing cloud coverage increasing over NW Colorado with
the incoming shortwave that will dissolve ahead of reaching the
divide. However...the disturbance will bring increasing moisture and
a chance of light snow in the mountains tonight and through Friday.
Winds will remain light with some QG and orographic influence aiding
in snow fall over the higher terrain. The upper low will drop into
the desert SW increasing mid level moisture from the Gulf into
Colorado. This will combine with a surface high developing over
Wyoming to turn winds to a more favorable ENE upslope direction by
Friday afternoon. This will bring a slight chance of flurries to the
foothills and possibly over the I-25 corridor by late Friday. Snow
fall over the higher foothills will be higher then the lower
foothills due to the upslope not being very deep and limited
moisture. Temperatures on Friday will be cooler then today with
highs hovering around the freezing mark and lows in the teens.

.LONG TERM...(Friday night through Thursday)
Issued at 309 PM MST Thu Dec 1 2016

Early in the forecast period will see the remnants of the weak
disturbance moving out of the state. Lingering snow flurries over
the mountains and plains will come to an end by sunrise Saturday.
The weekend will feature moderate westerly flow aloft across the
state as Colorado lies just to the north of the deformation zone
on the north side of an upper low moving across Texas. Dry
conditions will prevail and temperatures will moderate back to
around seasonal normals.

From Monday night through Wednesday, it continues to look like the
first Arctic outbreak of the season will dominate the Colorado
weather picture. The coldest air will be moving into the state
through Tuesday and lingering over the region through Wednesday.
Model thermal fields show 500 mb temperatures dropping to -36C or
less and 850 mb temperatures down to -10C. This corresponds to
surface temperatures around 20F on the plains and even colder in
the mountains. Light snow will accompany the arrival of the Arctic
front with some initial assistance from the nose of an upper level
jet stream dropping out of the Pacific Northwest. It is too early
to tell how much moisture the system will eventually contain, but
for now the main story will be the drastically colder temperatures
that people should be prepared for.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 845 PM MST Thu Dec 1 2016

VFR conditions expected through 15z-18z Friday, then cigs
approaching ils restrictions with cigs bkn050-060 kft agl 18z-02z,
with improvement thereafter. Have delayed on onset of vcsh in the
tafs as well until 18z at KDEN, could be a little sooner at KBJC
and KAPA. Overall light winds, generally at or blo 10 kts, and
southeast/easterly in direction.




LONG TERM...Dankers
AVIATION...Cooper is the U.S. government's official web portal to all federal, state and local government web resources and services.