Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 120205

Area Forecast Discussion
National Weather Service Denver/Boulder CO
705 PM MST Mon Dec 11 2017

Issued at 701 PM MST Mon Dec 11 2017

No updates planned this evening with only minor grid adjustments


.SHORT TERM...(This evening through Tuesday)
Issued at 344 PM MST Mon Dec 11 2017

A dry cold front moved over the far eastern plains earlier this
morning slightly raining RH levels as well as winds. Currently,
winds speeds are sustained between 20 and 25 with gusts to 40 mph
east of a line from Cheyenne to Limon. Winds will continue to gust
through the early evening before tapering off. The strong upper
ridge over the western CONUS continues to bring dry and
unseasonably warm temperatures. Tuesday will be no exception with
with sunny skies and near record highs in the mid 60s. A lee side
low will deepen through the morning helping to increase
downsloping and warm temperatures along the Front Range. Winds
will remain lighter than today but with some light gusting
possible with mixing in the afternoon. Overnight lows will dip
into the upper 20s on the plains and teens in the mountains with
single digits possible in the mountain valleys and higher

.LONG TERM...(Tuesday night through Monday)
Issued at 344 PM MST Mon Dec 11 2017

Strong upper level ridging will dominate the weather picture
across the western U.S. for the next few days with warm
temperatures and mostly sunny skies on Wednesday. Flow over
Colorado Will be out of the northwest.  The medium range models
show a short wave embedded in the northwesterly flow moving over
Colorado on Thursday. This will bring a dry surface cold front
into the area with cooler temperatures. The ECMWF also brings some
moisture with the passing trough, but the GFS keeps things drier.
Have mentioned a slight chance of snow in the mountains late
Wednesday night and Thursday, in case a batch of Pacific moisture
is able to work its way through the ridge in the next 24-36 hours.
If there are mountain snow accumulations, they should be less than
a couple inches. The other impacts Thursday will be an increase
in winds on the plains Thursday afternoon, in the tightened
gradient behind the surface cold front. Warmer temperatures are
expected to return Friday as the upper ridge re- strengthens.

Over the weekend, the medium range models show the upper ridge
breaking down in the face of a stronger Pacific trough. This
system will have a better chance of generating snowfall in the
mountains. This system is currently out over the Pacific, to the
north of Hawaii, and is receiving energy from a strong jet located
over the western Pacific. The GFS has the strongest solution with
the weekend storm. There are few other details to add to the
forecast at this time other than the chance of snow in the
mountains from Saturday through Sunday morning. Areas on the
plains may see some precipitation as well.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 701 PM MST Mon Dec 11 2017

VFR with no impacts. South/southwesterly drainage winds overnight
expected at the terminals, with speeds generally less than 10 kts.


Issued at 701 PM MST Mon Dec 11 2017

For Tuesday continued dry conditions with highs 15 to 20 degrees
above normal will create another critical fire weather day. Winds
will be lacking so no highlights at this time.




LONG TERM...Danker/Sullivan
FIRE WEATHER...Cooper/Bowen is the U.S. government's official web portal to all federal, state and local government web resources and services.