Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 271229
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
529 AM MST Mon Feb 27 2017

.SHORT TERM...(Today and tonight)
Issued at 529 AM MST Mon Feb 27 2017

There are some issues with the incoming trough. We have been
expecting a shallow moisture layer coming into the mountains to
deepen today and produce snow that peaks with the trough passage
this evening. In the real world there are lots of holes in the
cloud cover upstream and ceilings are still above mountain top
level all the way back into utah. Salt Lake City and Evanston just
started to snow, but that moisture is headed into Wyoming and it
appears to be drier at low levels further south. Cooling aloft and
destabilization is still way back in Nevada, and the south edge of
this is also about 100 miles further north versus what the models
were showing yesterday. Upshot of all of this is that there will
not be much snow today, and it appears that we will remain in a
relatively dry slot between the cold advection showers to our
north and the developing jet-related precipitation to our south.
There will be some snow out of the marginal shallow cloud layer,
with some increase in the afternoon and evening as lift increases.
However at this point we expect the significant snow to be limited
to areas north of Rabbit Ears Pass and Rocky Mountain National
Park.

For the plains the issue of the day is fire weather. See the
discussion below for details. Overall little change to the
forecast here, added a little more wind in the late afternoon and
early evening per the latest guidance, but it will still be
strongest along and south of Interstate 70. Forecast temperatures
look good.

.LONG TERM...(Tuesday through Sunday)
Issued at 529 AM MST Mon Feb 27 2017

The next system looking more progressive in its timing. Spatial
cross-sections not as generous in the mountain regarding the
moisture but still should see light to moderate snowfall in the
high country through Tuesday night. Weak to moderate mid level qg
ascent across southern CO through 18z Tuesday, then decreasing in
the aftn. Best chc for snowfall will late Tuesday aftn/early
evening. Best potential for snow will be south and southeast of
Denver qpf is limited there as well. Moderate qg descent is
progged to develop Tuesday night continue on Wednesday. Spatial
cross sections indicate bora winds developing 03z-15z Wednesday.
Best downward transport will be behind the mid level trough axis
Tuesday evening when mid level cold air advection moves across
the cwa. Mid level lapse rates in the 7-8c/km range at that time.
There could be a brief period of decent convective snowfall around
00z but it should be quite brief. Thursday through Sunday will be
dry and warmer with a ridge of high pressure becoming the main
influence. The mdls indicate the next potential system could bring
a chance of snow to the mountains Sunday aftn, but the northeast
plains should remain dry and mild until Monday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 529 AM MST Mon Feb 27 2017

VFR through tonight. Southwest winds will increase around 19z with
gusts in the 20 to 30 knot range. The winds will continue into the
evening, probably becoming westerly around 06z.

&&

.FIRE WEATHER...
Issued at 529 AM MST Mon Feb 27 2017

Southwest winds will increase during the day today, especially
south of Interstate 70. This will also be the area with the driest
air. While it will be warm, dry, and windy from Denver east across
the plains, Red Flag Conditions are only expected to be met south
of a line from about Burlington to Colorado Springs. Therefore,
the Fire Weather Watch has been cancelled in for areas further
north and a Red Flag Warning has been issued for fire weather zone
247, which includes southern Lincoln and southeast Elbert
counties. Humidities will probably still be marginal in this area
but there will be plenty of wind. While humidities will rise in
the evening, it will remain windy so if there are fire starts
conditions may remain difficult through the evening.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag warning from noon until 6 PM MST for COZ247.

&&

$$

SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Gimmestad
FIRE WEATHER...Gimmestad


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