Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 250904

Area Forecast Discussion
National Weather Service Denver/Boulder CO
304 AM MDT THU AUG 25 2016

.SHORT TERM...(Today and tonight)
Issued at 304 AM MDT Thu Aug 25 2016

Upper level trough over eastern Colorado will move east of the
state this morning. Subsidence behind the trough is resulting in
clearing over much of Colorado this morning. Westerly flow aloft
will prevail through tonight behind the exiting trough over the
Central Plains and the approaching trough currently over southern
Idaho. The clearing this morning should allow to airmass to warm.
Highs are expected to reach the 70s across northeast Colorado.
Like the previous system, instability and moisture will be
limited. CAPE will generally be less than 500 J/kg and
precipitable water values will range from three-quarters of an
inch to one inch over the Front Range and eastern plains. Models
in decent agreement that scattered thunderstorms will form over
the higher terrain ahead of the and move eastward through the
afternoon and evening hours. Lift associated with the trough is
expected to produce scattered showers and few thunderstorms
through the evening and overnight hours, so will keep the pops
going through the night.

.LONG TERM...(Friday through Wednesday)
Issued at 304 AM MDT Thu Aug 25 2016

A weak west/southwesterly flow with a couple of weak embedded
troughs will allow for an unsettled weather pattern to continue
for friday and saturday. The mdls maintain a fair amount of
subtropical moisture over Colorado on Friday with weak mid level
qg ascent aloft. Precipitable water values fm arnd 0.8 to 1.0
inches.  NAM12 forecast sounding show good instability in the
afternoon with CAPES n the 100O-1500 j/kg from around Denver to
Limon...with lesser CAPES and more CIN over the northeast plains.
This is not the same area as was pegged in the earlier mdl runs.
Main focus will occur wherever the best aftn heating takes place.
At this time...the mdls have the northeast plains in a cooler more
stable environment. In any event...the potential for a few
strong/severe storm still does exist. The mdls do shift the first
trof axis to the east Friday night...allowing for some weak mid
level subsidence for Saturday morning. An even weaker disturbance
is progged to move out of the Four Corners region on Saturday and
pass across the cwa. Moisture still around but overall coverage
should be less. Not much change in the grids regarding the rest of
the period. A ridge of high pressure will allow for a drier and
warmer airmass to build over CO from the west for Sunday through
Wednesday. Best chc of tstms will be over the mountains...with
little or no tstm activity over the lower elevations with temperatures
will be back above normal for next week.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 304 AM MDT Thu Aug 25 2016

Clouds will increase after 18z with the approach of the next
upper level system. There will be a chance for showers and
thunderstorms after 21z through about 03z. Showers and a few
thunderstorms will remain possible through Thursday night as the
upper level trough moves across Colorado. Low clouds will also be
possible after 06z as the airmass moistens. Ceilings could fall
below 3000 feet towards 12z Friday.

Winds will be tricky this morning. Southerly winds are expected
switch to the northwest to north after 12z as a weak Denver
Cyclone moves across the area. After 18z, surface winds are
expected to be east to southeast.


.BOU Watches/Warnings/Advisories...


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