Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 241030

Area Forecast Discussion
National Weather Service Denver/Boulder CO
330 AM MST Tue Jan 24 2017

.SHORT TERM...(Today and tonight)
Issued at 330 AM MST Tue Jan 24 2017

Latest satellite analysis shows upper low spinning just west of
Casper Wyoming, with another piece of energy now pushing northeast
from the Four Corners area. The main cold front has hung up in
east central Wyoming into the Nebraska panhandle as some pressure
falls were still noted into southeast Wyoming. Better falls were
seen under the short wave in the Four Corners. As that shortwave
lifts out, should see stronger pressure rise/fall couplet develop
finally allowing front to surge southward through northeast
Colorado. Behind that, shallow anticyclonic upslope develops in a
slightly unstable atmosphere, so expect scattered snow showers to
develop across the plains and I-25 corridor later this morning.
Still not entire sure about how this unfolds but feel at least
scattered PoPs would be warranted in this scenario. Any showers
that develop may drop brief moderate snowfall with a quick dusting
to 1 inch possible.

Into late this afternoon and evening, the anticyclonic upslope
component would have a tendency to increase and deepen. While most
synoptic scale energy is departing and low levels begin to dry,
there still appears to be sufficient instability under the upper
trough to keep the chance of snow showers in the forecast. Most
likely during this time frame there would be a focus toward the
Front Range foothills from Boulder southward. On the northeast
plains it should turn drier but as system organizes in Nebraska
would expect some wrap around moisture to bring an inch or so of
snow to the far northeast corner of the state. Chance of snow on
the plains will decrease late this evening.

In the mountains, expect mostly light snow off and on through
tonight with modest orographics and moisture. Will leave existing
advisory for zone 31 in place, while most mountain locations
should pick up another 1-4 inches through tonight.

.LONG TERM...(Wednesday through Monday)
Issued at 330 AM MST Tue Jan 24 2017

Drier and warmer conditions for the extended period. Wednesday
will see increased moisture behind the trough with mostly cloudy
skies through the morning slowly scattering out by the late
afternoon as increased subsidence returns. Flow from the north on
the plains provided by the exiting surface low over Eastern Kansas
could bring a slight chance of snow to the far NE plains counties
and the mountains into the evening hours. Some light accumulation
will be possible in the mountains with little to none on the
plains. Temperatures will be cooler on Wednesday behind the front
with highs hovering right around freezing and overnight
temperatures into Thursday in the single digits to low teens.

Thursday will see the building in of a surface high that will
dominate the mesoscale picture for most of the extended period.
There will be enough moisture in the mountains for a slight chance
of snow on Thursday but POPS will decrease substantially by the
evening. Temperatures on Thursday will increase into the upper 30s
and then to normal by the weekend with a chance of above normal
temperatures in the 50s by Monday under a moderately strong ridge.
With the surface high dominating most of the Western portions of
the CONUS with strong flow out of the north provided by the trough
over the Great Lakes some increased winds will be possible over
the plains with gusts reaching into the 30s by the weekend.
Otherwise conditions will be dry under partly cloudy skies.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 330 AM MST Tue Jan 24 2017

Patches of stratus with IFR conditions had developed across
portions of the Front Range including KDEN. Given the patchy and
weakly forced nature of this stratus, appears this may come and go
through 15Z before cold front pushes in and locks a more
persistent MVFR ceiling into place. With the front, also expect
scattered snow showers to develop with potential for isolated to
scattered LIFR ceilings and visibilities in the showers. Overall
trend will be for gradual ceiling improvement into the
afternoon/evening as low levels dry out and Lifting Condensation
Levels (LCLs) rise. However, instrument landings are likely to
persist at KDEN til around 06Z-08Z this evening before ceilings
sufficiently lift. Any snow showers will be capable of producing a
dusting to 1 inch of snow, with brief slush on paved surfaces.


Winter Weather Advisory until 5 PM MST this afternoon for COZ031.



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