Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 210306

Area Forecast Discussion
National Weather Service Denver/Boulder CO
806 PM MST Tue Nov 20 2018

Issued at 804 PM MST Tue Nov 20 2018

Other than a few tweaks to lows and winds no
other changes needed to prevous forecast.


.SHORT TERM...(This evening through Wednesday)
Issued at 234 PM MST Tue Nov 20 2018

A good travel day upcoming for Colorado on Wednesday before
Thanksgiving.  High pressure ridge aloft will gradually shift
over Colorado by late Wednesday with a weak northwest flow aloft.
Airmass will  remain very dry with mainly clear skies. Will
continue to see warmer temperatures as 700mb temperatures climb
to close to +2C leading to readings in the lower to mid 60s on
the plains.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 234 PM MST Tue Nov 20 2018

Thanksgiving will be another mild day with southwest flow aloft
ahead of the next weather disturbance. There will be an increase
in high clouds during the day, and at this time of year with a low
sun angle that always makes for a tricky temperature forecast.
Inversions should be fairly shallow which will aid warming, but
valley locations like Ft Collins-Greeley-Fort Morgan may be slow
to warm so held those locations back a few degrees.

In the mountains, Pacific moisture will arrive by late
afternoon/early evening on Thanksgiving, with snow developing and
becoming more widespread through the evening. Roads will likely
become snow covered later in the night and into Friday morning
across the high country, but overall accumulations are only
expected to be in the 1-6 inch range across the mountains and high
valleys from Thursday night through Friday, and generally below
Advisory amounts. Precipitation is expected to decrease in
intensity and coverage on Friday.

Winds will increase across the Front Range Mountains and Foothills
by late Thursday night with the strengthening gradient and flow
aloft. Then, gusty winds will spread across all of the plains
late Thursday night into Friday with the upper level trough
passage. We`re not seeing a high wind threat at this time, but
would not be surprised to see peak gusts reaching 60+ mph over the
Front Range, and 40-50 mph across the plains.

We continue to keep our eyes on the next storm system which will
move into the area late Friday night and Saturday. There is still
considerable uncertainty with regard to how quickly this storm
digs in and cuts off. The ECMWF has trended farther north/east
over the last couple days, while GFS and its ensembles are rather
well spread. Most of these runs would bring a significant snow
event to the mountains, while only a couple (and the Canadian)
show threats for heavier snow on the plains by Saturday night.
This storm is dynamic with a lot of Q-G forcing noted on all
models, no matter where the storm goes. Therefore, we will
continue to monitor the latest model solutions and watch this
potential for a stronger storm to affect not just the mountains,
but portions of the plains as well. Winds will also be strong with
deep cyclogenesis over the high plains.

After that, we should settle into a drier but breezy pattern into
early next week. There may be a couple weak waves to watch for
mountain snow showers. Overall, however, a more active weather
pattern seems to be in the works for the next couple weeks.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 804 PM MST Tue Nov 20 2018

Winds were becoming more southerly early this evening and
will be south to southwest overnight with VFR conditions.




SHORT TERM...Entrekin
LONG TERM...Barjenbruch
AVIATION...RPK is the U.S. government's official web portal to all federal, state and local government web resources and services.