Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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000
FXUS65 KBOU 262146
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
246 PM MST Sat Nov 26 2016

.SHORT TERM...(This evening through Sunday)
Issued at 225 PM MST Sat Nov 26 2016

Upper ridge of high pressure will shift east of Colorado tonight
in advance of next pacific storm system moving inland across
California this afternoon. Expect high level moisture will move
into Colorado this evening then lower level moisture moves into
mountains later tonight and early Sunday morning. Decent QG
forcing with this initial wave along with strong 150kt jet moving
into Southern Colorado. Initially mountain top flow will be from
the southwest which is not favorable for a lot of snow in zones
33/34. The orographic component will improve Sunday afternoon as
the flow turns west to northwest and increases. Overall amounts in
the mountains for sunday will be 2-4 inches with local higher
amounts in zone 31. will continue with the ongoing hilites that
have already been posted however amounts especially in zone 34 may
be under criteria.

Despite the marginal snow...strong winds will develop over
mountain passes and east slopes Sunday afternoon as subsidence
kicks in behind the lead shot of energy. cross barrier flow
increasing to 40kt so could see some gusts in the 40-60 mph range
with the strongest winds expected Sunday evening. Have added
blowing snow to the forecast due to the ongoing snow and strong
winds.

Across lower elevations as the system moves out to the
Northeast...given the QG forcing will allow some showers to
develop. NAM appears the most bullish with this but seems a bit
overdone. No real upslope component so will keep pops in the
slight chance over the Front range and a bit higher over the
plains. Temperatures will turn cooler on Sunday as the system
passes by.

.LONG TERM...(Sunday night through Saturday)
Issued at 225 PM MST Sat Nov 26 2016

Colder temperatures are expected across all of north Central and
northeastern Colorado early next week as a large and deep upper
level trough of low pressure deepens across the Rocky Mountain
Region and northern Plains States. Most of the energy will be across
the Dakotas and upper Midwest associated with a deep upper level low
pressure system and to the south of our CWA with the upper level
jet. However...some orographic lift due to a westerly to
northwesterly flow aloft combined with increased moisture...cold air
advection and several upper level disturbances will bring a
prolonged period of light to moderate snow across the high country
through Wednesday morning. The mountains and foothills could also
see windy conditions Sunday night into Monday morning due to
moderate to strong winds at mountain top level and a critical level
around 350 mb. These winds combined with snow could produce areas of
blowing and drifting snow in the mountains...especially above
timberline. Have decided not to issue a high wind watch at this
time due to the fact that the mountain top stable layer is
somewhat high (around 500 mb) and the ample moisture along and
west of the mountains could dampen the mountain wave. At the
surface...a strong pressure gradient will set up between western
Colorado and and the northern Plains states. This gradient
combined with the upper level pattern would suggest mostly dry and
breezy conditions across the plains due to downsloping flow.
However...a few light snow showers could develop on the plains
east of Denver and across the Palmer Divide Monday night and
Tuesday...as weak upslope flow develops behind the passage of a
cold front.

Drier weather is expected on Wednesday and Thursday as upper level
high pressure builds over the central and southern Rockies. However
temperatures should remain on the cool side. Another storm system
drops into the desert southwest on Friday and moves into the Baja
over the weekend. Most of the weather with this system should stay
well to the south of our CWA...with only scattered light snow
showers possible in the mountains. Surface high pressure building
into Colorado from the north on Friday should result in cold and
cloudy weather across northeastern Colorado...with isolated light
snow showers in the foothills and few flurries on the plains.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 225 PM MST Sat Nov 26 2016

Expect increasing high level moisture beginning this evening then
a gradual lower of ceilings later tonight. A weather system will
move over the region on Sunday which may lead to isolated rain and
snow showers especially Sunday morning. Surface winds will shift
back southerly tonight before increasing from the West and
Northwest later Sunday morning and afternoon hours.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 6 AM Sunday to 5 AM MST Tuesday for
COZ033-034.

Winter Storm Warning from 6 AM Sunday to 5 AM MST Tuesday for
COZ031.

&&

$$

SHORT TERM...Entrekin
LONG TERM...Kalina
AVIATION...Entrekin



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