Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS65 KBOU 161058

Area Forecast Discussion
National Weather Service Denver/Boulder CO
358 AM MST Mon Jan 16 2017

.SHORT TERM...(Today and tonight)
Issued at 355 AM MST Mon Jan 16 2017

Upper level low over Oklahoma will lift northeast across Kansas
today. The system will continue to move northeast and exit the
region this evening. Northeast upslope winds at 700 mb is helping
to produce snow along the Front Range at this time. Radar showing
the heaviest snow is occurring west of I-25. Moisture will
continue to wrap around the low move over northeast Colorado this
morning. With the low pulling away from the state moisture and
lift will decrease. Expect snow to end mid to late morning for
most locations. Upslope areas south and west of Denver and areas
closer to the low over the eastern plains will likely see light
snow linger into the early afternoon. Expect snow to end by sunset
everywhere as drier air moves in from the north. This drier air
will bring clearing skies. By 12z Tuesday, expect mostly clear
skies through out the forecast area. This will lead to chilly
overnight lows in the mountains valleys with lows approaching

As far as snowfall amounts go, temperatures in the mid 20s to
lower 30s should keep the liquid to snow ratio close to 10 to 1.
Expect 1 to 3 inches along the Front Range and across the eastern
plains. Upslope favored areas in and near the foothills could see
a little more snow, 2 to 5 inches. Will continue the Winter
Weather Advisory where additional snowfall should result in slick
roads this morning.

.LONG TERM...(Tuesday through Sunday)
Issued at 355 AM MST Mon Jan 16 2017

Elongated upper trough extending from the upper low over the
western Great Lakes to an upper low spinning just south of the
Arizona may still provide sufficient mid-level shear...instability
and moisture for scattered to broken cloud cover over the srn
third of the fcst area to start the day on Tuesday. However any
precip should be south of the CWA by then. Through the day trough
translates eastward allowing drier and progressively warmer air
to spread across the region beneath a strongly tilted upper ridge.
For the next two days daytime temperatures climb into the 50s at
lower elevations and into the 30s across the high country under
generally clear skies even as a weakly organized upper low ambers
by to our south. By Thursday night...models show the ridge
shifting east of the state opening the door to a series of
progressive shortwave troughs. Models overall indicate the first
of these waves reaching western Colorado by Thursday evening with
its comes plenty of cloud cover...precip and gusty swly winds. At
this point it does not appear to be a prolific snow producer with
its south-southwesterly mean layer flow and weak QG forcing. As
this wave swings out over the state`s northeast plains could see a
few light rain and/or snow showers late Thursday afternoon and
evening with weak low-level upslope flow. Should then see a break
in precip and partial clearing with a passing weak shortwave ridge
in Friday...followed by a return of clouds and precip in the form
of light to possibly moderate snowfall for the high country on
Saturday with what looks to be a somewhat stronger and wetter
trough swinging across the Colorado. Areas east of the mtns appear
to miss out on most of this precip with models showing the trough
accelerating once it crosses the Rockies. However, a moist and
marginally unstable flow on the back side of this trough make
continue to produce snowfall in the northern mtn ranges possibly
until early Sunday morning. Should see rapid clearing and slight
warming from west-to-east across the CWA on Sunday with fairly
strong nwly flow aloft leading an upper ridge passing through the
Great Basin. Models all agree in advancing this ridge east of
Colorado by Monday morning which then exposes the region to a long
southwesterly fetch of very moist air of maritime origin which
could result in significant snowfall for mtn areas particularly
west of the Continental Divide. Any precip east of the mtns
according to models may not come until Monday night or Tuesday.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 355 AM MST Mon Jan 16 2017

Light snow will continue this morning and end around 18z.
Visibility will generally range from 1 to 3 miles in the snow with
ceilings of 500 to 2000 feet. Snowfall of up to 2 inches is
expected at KDEN with up to 3 inches at KAPA and KBJC. Ceilings
will improve after 18z and the clouds will scattered around or
shortly after 00z. Northwest winds will continue through 00z at
speeds less than 20 knots. After 00z, winds will turn southerly.


Winter Weather Advisory until 11 AM MST this morning for COZ041-



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