Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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470
FXUS65 KBOU 260343
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
843 PM MST Sat Feb 25 2017

.UPDATE...
Issued at 843 PM MST Sat Feb 25 2017

No big changes to the forecast necessary this evening. Winds along
the foothills earlier this evening have diminished and generally
light winds are expected overnight on the plains. Gusty winds
will continue over the higher mountain ridges through the night as
moderate westerly flow aloft continues over the state. Drier air
will be moving over the state through the night, and snow showers
over the mountains will be on the decrease with additional snow
accumulations less than a few inches.

&&

.SHORT TERM...(This evening through Sunday)
Issued at 345 PM MST Sat Feb 25 2017

Strong west-southwest jet level flow ahead of a weak upper-level
trough just about to move over western Colorado will pass over
the forecast area overnight. The strong nearly zonal flow aloft
will combine with a low amplitude mtn wave and a sfc lee trough
to produce gusty westerly surface winds in the mountains and on
the adjacent high plains until around midnight tonight. Gusts in
the 25-35 mph range have already developed on and along the base
of the Front Range as far east as Denver International Airport.
This evening could see slightly stronger gusts materialize with
gusts in the 50-60 mph range up around timberline and on higher
east slopes of the Front Range. In addition to the winds, a
compact region of weak to moderate QG ascent in the warm sector
of the shortwave trough now over eastern Utah/western Colorado is
producing light to moderate precip in the same area. Precip looks
convective on radar. This area of showers, mainly in the form of
snow, is projected to track east-southeast with the trough,
clipping the southwest quadrant of the CWA over the next several
hours. Because of the relatively fast progression of this showery
precip, snow amounts should be light...generally 2 inches or less
on the valleys floors and 5 inches or less at higher elevations.
Most of this precip should wrap up not long after midnight with
drier and more stable air moving in behind the trough. Winds both
sfc and aloft will also turn lighter late tonight. Areas east of
the mountains will remain dry tonight.

On Sunday...drier and slightly warmer air will spread over the
forecast area with the upper-level trough exiting the state by
around midday. However, another upper air disturbance swinging
down from the Pacific northwest will return clouds and a few
showers to the northern mtns by mid to late afternoon. Mid and
high-level clouds will also spread from northwest-to-southeast
across the CWA late in the day. Expect lighter winds tomorrow due
to a light westerly flow aloft. Temperatures will remain below
average for the next 24 hours.


.LONG TERM...(Sunday night through Saturday)
Issued at 345 PM MST Sat Feb 25 2017

Flat upper ridge over Colorado Monday evening which will
transition to a more southwest component on Monday ahead of next
advancing trof. Moisture will be increasing over the mountains
during the day on Monday with snow become more widespread by the
afternoon hours. Still dry over the plains but an associated cold
front will drop down Monday night with cooler temperatures. Main
trof axis will move over Colorado late Tuesday and Tuesday night
with some potential for snow over the plains as well, with best
chance from Tuesday afternoon through the evening hours under
shallow upslope flow and weak to moderate QG forcing. Mountain
snowfall looks to be more advisory range, especially zone 31 which
will do a bit better with the initial southwest flow aloft.

There will be a drying and warming trend from Wednesday through
Friday with snow diminishing in the mountains on Wednesday
morning. Temperatures will climb above seasonal normals for the
Friday and Saturday time frame as Colorado remains under building
high pressure aloft.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 843 PM MST Sat Feb 25 2017

No aviation impacts through the next 24 hours. Skies will be
mostly clear and winds should be drainage southerlies overnight
and generally out of the south through tomorrow.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Dankers
SHORT TERM...Baker
LONG TERM...Entrekin
AVIATION...Dankers



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