Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 152204

Area Forecast Discussion
National Weather Service Denver/Boulder CO
304 PM MST Wed Feb 15 2017

.SHORT TERM...(This evening through Thursday)
Issued at 303 PM MST Wed Feb 15 2017

Today was a "chamber of commerce day" and tomorrow will be even
better unless you crave cold and snowy weather. A 500 mb low over
northern Mexico continues to retrograde towards the southwest. A
strong Pacific storm approaches the NW U.S. coast, and is building
a positively tilted ridge downstream over the Great Basin and the
Rockies. By Thursday midday the ridge axis will be squarely over
Colorado.Weak winds aloft and very dry air throughout the
atmospheric column mean no chance of precip and only a few high
clouds will dominate the sensible weather through Thursday.

The main story will be the high temperatures on Thursday.
Downslope winds should begin tonight across the Front Range
Foothills leading to warm overnight temps west of I-25 nearest the
terrain gradient. At this time the winds will be weak given the
location of the mid-upper level ridge. High res models are
showing a persistent surface high pressure over north central
Colorado and a weak lee trough along the front range. This
pressure gradient along the surface combined with weak westerly
flow aloft will allow west downslope winds to persist throughout
Thursday, albeit wind speeds will be light. This in turn will
allow temperatures to warm 5-8 degreesF over today`s highs.
Denver`s record for February 16 is 71 and expect the high temp to
tie or possibly break it by a degree or two. Elsewhere the Plains
will be in the upper 60s to low 70s. 700mb temps also warm
another 3-4 degC compared to today, so the mountains will be
quite warm tomorrow as well, and should warm into the mid to upper
40s across the high country and upper 50s to low 60s in the

.LONG TERM...(Thursday night through Wednesday)
Issued at 303 PM MST Wed Feb 15 2017

A split flow pattern over the state at the beginning of the
forecast period will result in benign weather Thursday night and
Friday. Southwesterly flow aloft will then begin increasing
through the weekend as another upper low develops over the
southwestern U.S.

The GFS and ECMWF have similar solutions through the weekend with
both models moving the southwestern U.S. upper low across
northwest Mexico and to southern Texas by Monday evening. While
Colorado remains under the deformation band to the north of the
upper low, light precipitation will move over the state, mostly
Sunday through Monday. Another upper ridge will build over the
state through the middle of next week. Temperatures will be warmer
than normal through the period, owing to the general southerly
flow aloft.

Given the pattern of generally weak flow aloft, and the state
lying under the deformation region to the north of the passing
low, any periods of precipitation are going to be light. No
significant mountain snowfall is expected. Also the warm
temperatures may result in the precipitation on the plains falling
in the form of rain.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 303 PM MST Wed Feb 15 2017

VFR conditions are expected through 00Z Friday. Winds 5 kt or less
will continue through this evening at the three terminals. Afer
03Z or so drainage winds should kick in and last into mid morning
Thurdsday. For Thursday models continue to show a deepening
surface lee trough along the I-25 corridor. This would result in
generally southwest flow during the day but wind speeds should
remain in the 10 kt range or less.




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