Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 251046

Area Forecast Discussion
National Weather Service Denver/Boulder CO
346 AM MST Sat Feb 25 2017

.SHORT TERM...(Today and tonight)
Issued at 346 AM MST Sat Feb 25 2017

Drier air moving over Colorado today as northwest flow aloft
increases a bit. There will still be some mid/high level clouds as
well as some weak lower level clouds upstream of the mountains,
but only patches of very light snow for the mountains this
morning. With some heating and increasing moisture this afternoon
mountain showers will increase again. This will be a shallow layer
of instability but with decent wind, so it should be mainly light
to moderate showers. Most of the mountains should get a little
snow through the evening, then drier and subsident air will move
in from the north after midnight. For the plains there will be
mid/high cloud cover and possible some weak late day convection,
but with dry low levels expect this will only produce virga.

Forecast temps look pretty good today, lowered tonight`s low a
little as we were above guidance and with clearing expected it
could be just as cold in northern valleys and plains low spots as
it is this morning.

.LONG TERM...(Sunday through Friday)
Issued at 346 AM MST Sat Feb 25 2017

Aside from some residual snowfall in the mountains along the
higher west facing slopes, Sunday and Sunday evening will be dry.
The models show weak qg descent through the day, under a light
west/northwesterly flow aloft. The flow aloft will increase and
become more west/southwesterly late Sunday night into Monday.
Weak qg ascent will develop over the cwa as the next storm system
approaches the state from the Pacific Northwest. The first system
will move across the cwa Monday afternoon. Southwesterly mid
level winds will favor zone 31 the most. The trough axis will pass
to the east Monday evening allowing the mid level winds to
transition to northwest. The best round of accumulating snowfall
will occur Monday afternoon and evening. Moderate mid level
subsidence kicks in after 06z Tuesday which will allow for mainly
light orographic snowfall in the high country. Across the
northeast plains, spatial cross-sections show some shallow
moisture around late Sunday night, but mostly dry aloft so no pcpn
anticipated through Monday night altho there could be some
stratus stirring around the northeast plains. The mdls push the
cold front across the area 03-06z Monday evening. The second part
the storm system push across the Desert Southwest 12z Tue and
clips southern and eastern CO Tuesday aftn/evng. The mdls develop
a weak sfc low near the OK/TX Panhandles Tuesday aftn, then flush
the sfc low eastward Tuesday evening. The mdls show a brief window
for snow mainly for east central CO, so maybe some light
accumulations to the east/southeast of Denver late Tuesday
aftn/evng. High pressure at the sfc and aloft will allow for a
drier pattern by the middle of next week and continuing into next
weekend, with temperatures climbing back to around 60 by Saturday.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 346 AM MST Sat Feb 25 2017

VFR through tonight. Some uncertainty in wind direction today,
mainly for KDEN/KAPA. Winds may tend to the WNW with light speeds
this morning. Stronger WNW winds north of Denver may produce a
Longmont anticyclone eddy with winds trying to go to an easterly
direction into Denver this afternoon. West winds are more likely
to persist at KBJC and could occasionally gust to 25 kt. A more
typical S/W drainage wind pattern should resume this evening.




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