Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 142135

Area Forecast Discussion
National Weather Service Denver/Boulder CO
235 PM MST Tue Feb 14 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 235 PM MST Tue Feb 14 2017

The short wave trough at 500mb responsible for clouds and
precipitation across Southern Colorado yesterday is located
across the Red River Valley in Oklahoma and continues to slowly
move east. A dry northerly flow has developed in the wake of the
trough. Tonight through Wednesday night a strong mid and upper
level ridge will build from west to east across the state. The
trough axis will be located over the Great Basin by 00Z Wednesday.

The net result of the ridge building across the state is to jump
start a significant warming trend that will make it feel more
like mid-spring rather than mid-February. By midday Wednesday 700
mb temps will warm 8 degC in 24 hours. With the building ridge,
the jet stream 700 miles northeast of the state, and the nearest
low-level thermal gradient across the northern Plains, winds will
be relatively light across the CWA Wednesday through Wednesday
night. A weak lee trough will develop across NE Wyoming on
Wednesday resulting in weak west and southwest winds during the
day east of the mountains. This downslope flow, through weak and
shallow, combined with mostly sunny skies, will help max temps
across the Plains reach the mid 60s. The mountains will also
experience significant warming on Wednesday with highs in the low
to mid 40s, mid 50s in the foothills.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 235 PM MST Tue Feb 14 2017

A large upper level ridge of high pressure over the Rocky Mountain
Region will bring dry and unseasonably warm temperatures to north
central and northeastern Colorado on Thursday. Many plains locations
should see high temperatures in the 70s. On Friday...the ridge will
begin to break down as an upper level disturbance moves into
Colorado from the west. There looks to be a lack of moisture with
this system...with only isolated to scattered light snow showers
possible over the high country. A weak cold front will also drop
high temperatures across the plains back into the 60s.

On Saturday...the upper ridge rebuilds over Colorado as an upper
level trough of low pressure moves onto the west coast of the United
States. The main energy with this system digs way south into
northern Mexico/southern Arizona Saturday night into Sunday morning
leaving our CWA mostly dry. There may be just enough moisture and
weak orographics to produce a few light snow showers in the high
country...mainly south if Interstate 70.

Late Sunday into Monday...models shows the storm system splitting
with the main upper low moving across northern Mexico/southern
Texas...with a secondary weaker open trough moving across Colorado.
This pattern should bring a better chance of snow to the high
country...with cooler temperatures and a few light showers possible
across the plains. The far northeast plains could also see gusty
northwest winds to 35 mph in the afternoon. One thing to note is
that the 12Z GFS run shows less moisture and QPF across the
mountains than previous runs. Nevertheless...the mountains should
see some snow.

On Tuesday...another storm system approaches the Pacific West
Coast...with a moderate west to southwest flow aloft over Colorado.
Orographic lift and occasional upper level disturbances associated
with this pattern should result in scattered light snow showers
across the mountains...mainly across the higher peaks of zone 31.
The plains should remain mild and dry through the period.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 235 PM MST Tue Feb 14 2017

VFR conditions through 00Z Thursday and dry conditions expected.
With a building ridge aloft and weak pressure gradient at the
surface, drainage winds should ensue after 04Z at the three TAF
sites. Winds will remain light throughout Wednesday, expecting
generally a west and southwest direction during the day and
staying under 10 kts.




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