Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 181711

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1011 AM MST Wed Jan 18 2017

Issued at 1011 AM MST Wed Jan 18 2017

No cahnges to the forecast necessary at this time. Skies across
the state are nearly cloud-free except for some cirrus clouds
rotating around the northern fringe of the upper low spinning over
southwest Kansas. These should have little impact on the weather
as temperatures warm to the upper 40s and lower 50s across the
plains. Winds will remain light as a surface trough remains in
place over the i-25 corridor.


.SHORT TERM...(Today and tonight)
Issued at 324 AM MST Wed Jan 18 2017

High altitude easterly flow around the top of an upper low slowly
tracking eastward along the Colorado/New Mexico border and roughly
south of Alamosa is having little influence on northeast CO
weather this morning, other than to rotate a few bands of cirrus
over the area. Models show the center of the 500-300mb low lifting
northeast over northwest KS by 00z/Thursday. As the low passes to
our southeast, flow aloft is projected to go sely later this
morning which could spread in some more high clouds. Flow aloft
then becomes northeasterly and somewhat stronger this afternoon
which appears to further dry and warm the air over the forecast
due in part to an increase in mid/upper-level subsidence. In
addition...pressure falls along the Front Range through the day
should enhance the downslope gradient which will further aid in
warming temperatures over and near the Front Range foothills
through the overnight hours. Could see downslope winds gusting in
the 30-40 mph range in the foothills towards morning.

With further snow melt today, expect temperatures to warm another 5-
8 degs F in the foothills and across the urban corridor, while
farther east the warmup should not be as pronounced esply in lower
areas along the South Platte River. Mountain valleys will also be
slow to warm today esply where patchy dense fog could linger until
mid-morning. Lows tonight slightly warmer all areas with warmest
readings within the Chinook zone at the base of the foothills.

.LONG TERM...(Thursday through Tuesday)
Issued at 324 AM MST Wed Jan 18 2017

A series of Pacific storm systems will influence Colorado weather
from Thursday night through early next week which will bring a
return to cooler temperatures and a chance of snow in the
mountains and even lower elevations. The first system will
increase moisture over the mountains late Thursday with areas of
light snow spreading over the mountains Thursday night and Friday
before diminishing Friday night. Orographic flow is weak with this
system but there is some weak to moderate QG ascent that rapidly
moves northeast across the state on Friday. Generally light
snowfall is expected during this time period. As this system lifts
out over Colorado on Friday there is even a chance for showers
across lower elevations as well given the decent ascent. However,
lack of upslope flow and speed of system will keep chances in the
20-40 percent range.

The second system brings return return moisture and snow to the
mountains on Saturday but main energy with this system will stay
across New Mexico and the panhandle of Texas. The strongest system
will impact Colorado next Monday and Tuesday as strong closed low
develops across Eastern Colorado and Western Kansas. The European
solution is a bit North of the GFS but both still showing good
chances of snow for much of Northeast Colorado on Monday night and
Tuesday. Still quite a bit of track and timing differences and
details to work out but certainly good potential for a widespread
snow event. Will continue to maintain high chance/likely pops
over the plains with the early next week storm.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1011 AM MST Wed Jan 18 2017

No aviation impacts today or tonight with light southerly winds
and unrestricted ceilings and visibilities.




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