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Area forecast discussion 
National Weather Service Denver/Boulder Colorado
936 am MDT sun Aug 2 2015

issued at 926 am MDT sun Aug 2 2015

Light precipitation coming to an end over the far NE corner with
the help of high dewpoints and the edge of an upper level jet.
Expect development to continue over the mountains with increased
moisture and an upper level wave. Increased probability of precipitation over the plains
with the cloud cover and a front north of Nebraska that is still
prognosticated to track into NE Colorado by this evening/early Monday
morning. Latest run of the hrrr has some gusty winds moving south
out of Wyoming from outflows provided by storm development to the
north. Maintained slight chance into the evening. Main threats
still look to be moderate to heavy rain and gusty winds with the


Short term...(today through tonight )
issued at 340 am MDT sun Aug 2 2015

Water vapor imagery showing elongated upper ridge from the
Pacific northwest and extending southeast into Colorado with a
west to northwest flow aloft over northern Colorado. Overall not
much change in moisture levels over eastern Colorado with
integrated precipitable water values just under an inch over the Front Range and
a bit higher over western Colorado. There is quite a bit of middle
and high level cloud cover now over the southern 2/3 of Colorado.
There is an upper wave over southern Nevada which will slowly
rotate into western Colorado tonight which will aid in additional
moisture and weak qg lift.

Initially...shower activity will be confined to the mountains by
early afternoon but slowly sneak out onto the plains during the
late afternoon. A weak middle level capping inversion remains which
will limit convection on the plains with overall surface based
cape values under 700j/kg. Appears a weak frontal boundary will
approach the far NE plains towards evening with a slight chance4
of thunderstorms sparking there. Temperatures expected to be very
similar to saturdays readings but maybe a degree or two down
closer to the Front Range with more cloud cover. Will keep low
probability of precipitation in the mountains through the night as the upper trough will
approach with aided moisture and lift.

Long term...(monday through saturday)
issued at 318 am MDT sun Aug 2 2015

Middle-level shortwave trough is still forecast to swing newrd across north-
central/northestern Colorado Monday afternoon/evening...then sewrd across eastern Wyoming/western
South Dakota/western NE on Tuesday as the upper ridge builds over the 4-corners region.
Should see scattered to numerous showers/T-storms in the high country
during the day Monday and scattered T-storms on the plains during the
afternoon and evening hours. System appears most robust on the NAM
and only lack luster on the European model (ecmwf). NAM generates some ridiculously
high convective available potential energy across the northestern corner of Colorado in the vicinity of a stalled surface
frontal zone straddling the northestern corner of the state and a low-level
jet aligned with the state's eastern border Monday night and Tuesday. GFS...
European model (ecmwf) and sref indicate far less instability but still indicate
decent shear in the vicinity of the low-level jet. Meanwhile the
Canadian model GOES so far as to spin up a closed 700-500mb low over
northestern Colorado late Monday and then deepens it as it slowly tracks east/sewrd
across northwestern Kansas overnight. Prefer a blend of the models...excluding the
Canadian Gem...centered on the GFS solution. For the plains...plan
on going with higher probability of precipitation up against the northern Front Range and along
the Wyoming border during the afternoon...and out across the northestern corner of
the state Monday night. Storms forming in the vicinity of the stalled
frontal boundary and low-level jet are more likely to produce heavy
rainfall...strong gusty winds and hail. High temperatures on Monday expected to be
several degrees lower than those on Sunday due in large part to
considerable more cloudiness.

On Tuesday...should see precipitation chances quickly decrease from west-to-
east as drier/cooler air sweeps in on west/northwesterly flow behind the exiting
shortwave. However could see a modest uptick in shower/T-storm
activity across the northestern corner of the County Warning Area Tuesday afternoon with the
short-wave dynamics brushing the area. Highs on Tuesday slightly
warmer than the day before but still below the seasonal average.

Wednesday through Sat...a strong upper ridge takes hold of the region on
Wednesday returning temperatures to slightly above average. Models show a weak
middle-level pertabation rounding the top of this ridge and possibly
generating a few T-storms across the far northestern corner of the County Warning Area Wednesday
afternoon and evening. Otherwise a dry day with more sunshine and
lower humidity. On Thursday...models show yet another somewhat stronger
middle-level disturbance moving out of the northern rockies and down across
the central Great Plains. The tail end of the disturbance appears to
clip the northestern corner of forecast area Thursday afternoon and evening and
potentially producing another round of T-storms. More clouds and
slight cooler aloft should result in slightly cooler temperatures on
Thursday. On Friday...Ridge regains its grip on Colorado resulting in
warmer temperatures and more sunshine. However with the warmer temperatures and
sunshine could see widely scattered afternoon T-storms forming
over the Front Range and moving out over the plains by the
evening. On Sat...models show the upper ridge moving east allowing
southwesterly flow aloft to usher in subtropical moisture and shortwave
trough from the Desert Southwest. Too soon to know with any
certainty how wet and stormy Sat may turn out. Will need to keep
an eye this late week system.


Aviation...(for the tafs through 18z Monday morning)
issued at 926 am MDT sun Aug 2 2015

VFR expected for the next 24 hours. Added some light rain showers in a
tempo with latest model guidance and a weak cap with increased
instability. Could see some outflows from the north that will help
to bring in some gusty winds along with a line of rainshowers
around 23z. Winds will be light through the day then transition to
the northwest before going to drainage by this evening as storms clear


Bou watches/warnings/advisories...


short term...entrekin
long term...Baker

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