Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 262249
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
349 PM MST Sun Feb 26 2017

.SHORT TERM...(This evening through Monday)
Issued at 345 PM MST Sun Feb 26 2017

A dry subsident airmass covering northern Colorado thanks to a
weak shortwave ridge passing overhead will shift east overnight.
In doing so, the light zonal flow aloft will become southwesterly
and also increase in speed with thermal packing aloft ahead of a
mid-level shortwave trough dropping down over the Great Basin.
Should see west-southwest sfc winds picking up speed through the
evening over the high elevations with the cross mtn wind
component approaching 45 kts by late tonight. Therefore should see
west winds of 25-40 mph in exposed mtn areas and gusts approaching
60 mph up around timberline as the night goes on. The gusty winds
are likely to produce blowing and drifting snow in open areas. At
lower elevations, winds not expected to be an issue except perhaps
near the base of the foothills where we may see an enhanced
downslope flow develop late.

On Monday...Swly flow aloft will continue to strengthen as the
upper trough nears the state. East of the mountain...falling sfc
pressure to our north will combine with the increasing swly flow
aloft to produce warm and gusty south-southwest winds on the
plains...particularly along the Palmer Divide east to Lincoln
County. Dry light fuels in the area...i.e. grasses and light
brush...will be susceptible with fire tomorrow afternoon due to
low RH and gusty winds. For that reason, have issued a Fireweather
Watch for fireweather zones 241...246 and 247 in east central
Colorado. The watch will run from 12 noon MST to 6 PM MST Monday
afternoon. Elsewhere...mid-level moisture will begin spreading
over northwest portions of the forecast area during the afternoon
ahead of the trough with scattered showers developing over higher
elevations. Snow level will gradually lower to the valley floors
by evening. Temperatures during the next 24 hours will run near to
slightly above average.


.LONG TERM...(Monday night through Sunday)
Issued at 345 PM MST Sun Feb 26 2017

Northern Colorado will be under the influence of an approaching
upper level trof Monday night and Tuesday. Improving orographic
flow in the mountains as winds shift w-nw Monday night and
Tuesday and improving lapse rates. Could see advisory type snow
amounts during these periods. Expect an associated cold front will
sweep across the plains late Monday night with shallow upslope
flow developing on Tuesday. As the upper trof kicks out over the
plains on Tuesday looks to be some showers that develop Tuesday
afternoon and evening. Focus still appears to be from Denver
southward down over the Palmer Divide with possible couple inches
of accumulation.

Behind the upper trof, a stronger northwest flow will develop over
much of the region with still some lingering snow showers in the
mountains and gusty winds. Expect an overall drying and warming
trend for all of Colorado, especially on Friday and Saturday.

&&

.FIREWEATHER...(This evening through Monday)

Strengthening southwest flow aloft and strong pressure falls in
Wyoming will combine to produce warm and gusty south-southwest
surface winds on the plains Monday afternoon. Strongest winds are
expected to develop by midday along the Palmer Divide east to
Lincoln County. Dry fuels...low relative humidity...warmer
temperatures under a mostly sunny sky and wind gusts in excess of
20 mph has prompted the issuance of a Fireweather Watch for
east central Colorado. This watch covered fireweather zones
241...246 and 247 and runs from 12 noon MST to 6 PM MST Monday
afternoon.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 345 PM MST Sun Feb 26 2017

Clear skies overnight under a weak upper level ridge will give way
to increasing high clouds tomorrow. The gusty west-southwest winds
late this afternoon across portions of the Denver metro area will
weaken and turn southerly with nightfall. On Monday, light
southerly winds early with steadily increase in speed through the
day...with the stronger winds occurring across southern and
eastern portions of the Denver metro area during the afternoon.
Could see gusts in the 20-30kt range at KAPA and KDEN after 20z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...Fireweather Watch Monday
afternoon for zones 241..246 and 247 in east central Colorado.

&&

$$

SHORT TERM...Baker
LONG TERM...Entrekin
AVIATION...Baker


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