Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 250350

Area Forecast Discussion
National Weather Service Denver/Boulder CO
950 PM MDT Sat Sep 24 2016

Issued at 940 PM MDT Sat Sep 24 2016

Mdls maintain weak mid level qg descent/subsidence over the cwfa
overnight. Weak nely winds overnight but not much in the way of
cloud development expected. Will go with primarily partly cloudy
east of the Continental Divide...and keep mostly cloudy conditions
to the west. As a result...have tapered back the pops some as
well. Expect light winds overnight should help to keep temperatures
above freezing across the urban corridor and northeast plains.


.SHORT TERM...(This evening through Sunday)
Issued at 254 PM MDT Sat Sep 24 2016

An upper level low is currently centered over northeastern Wyoming...
with an upper trough extending southward across the central and
southern rockies. Some light rain and snow showers continue to
fall across the high country...especially near the Wyoming border
where the best orographics and lift are. Precipitation is expected
to decrease after midnight as the upper flow weakens and
moisture/QG forcing decrease. The plains were mostly
and dry today...and should remain dry through the evening with
the exception of an isolated light shower near the Wyoming
border. The one concern will be low temperatures on the plains
tonight. Cross sections show plenty of mid and high
level cloudiness across the plains overnight...however Synthetic
Satellite imagery shows little to no cloudiness. The possibility
of fewer clouds and low dewpoints could lead to temperatures on
the plains in the 30s...therefore have lowered tonight`s min
temperatures by a few degrees. If we completely clear out...there
is an outside chance for areas of frost. Sunday will be a
cool...mostly sunny and dry day across the CWA...with only a few
morning mountain snow showers.

.LONG TERM...(Sunday night through Saturday)
Issued at 254 PM MDT Sat Sep 24 2016

A strong upper ridge is going to build over the western U.S. for
the first half of the week while a cutoff low moving over Baja
California creates a bit of a Rex Block. The blocking pattern is
forecast to remain in place through Tuesday afternoon with weak
winds aloft and a dry airmass over the state. Cloud cover will be
nearly absent through this period as temperatures gradually warm
up from day to day. However, at the beginning of the warming
trend, the dry airmass and clear skies could allow Monday morning
temperatures to drop into the 30s. Will mention patchy frost on
the plains, but not issue any highlight at this time.

By Wednesday night the upper low over northern Baja California
will begin shearing apart with the energy heading toward the Four
Corners region. This energy will then move over Colorado from
Thursday through Friday with periods of rain showers over the
mountains and then the plains. Since this system will be coming
out of the southwest, on the heels of warm ridging, snow levels
should initially be quite high, and the threat of snow minimal. It
is also too early to accurately assess the instability of the late
September airmass, so will refrain from mentioning very much
thunder in the forecasts and just have chance/slight chance of
rain showers.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 940 PM MDT Sat Sep 24 2016

VFR conditions through the period...although some bkn mid level
digs psbl prior to 09z. Sfc winds primarily nely until 08-09z
then sely. North/northeasterly winds again expected for the most
part on Sunday.




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