Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kbou 112244 

Area forecast discussion
National Weather Service Denver/Boulder Colorado
344 PM MST Mon Dec 11 2017

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 relative humidity 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 Continental U.S. 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
colroado wil 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 European model (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 18z tafs through 18z Tuesday afternoon)
issued at 344 PM MST Mon Dec 11 2017

VFR conditions are expected through the period. Winds will
continue from the north-northeast through 02z with speeds from 8 to 12 kts
with light gusting through the afternoon. By the evening winds
will veer around to the southeast before turning to drainage around 05z
this evening.


Fire weather...
issued at 344 PM MST Mon Dec 11 2017

Red flag continues through 5 PM with gusting up to 40 mph on the
plains and relative humidity levels in the low teens over the far eastern plains.
Conditions will steadily improve through the evening hours. 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...however, caution is
urged with any burning.


Bou watches/warnings/advisories...
red flag warning until 5 PM MST this afternoon for coz238-242-



National Weather Service Glossary of Abbreviations