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Area forecast discussion 
National Weather Service Denver/Boulder Colorado
326 am MDT sun Jul 5 2015

Short term...(today through tonight )
issued at 326 am MDT sun Jul 5 2015

Water vapor imagery shows one short wave lifting northward through
northern Nevada and western Utah...with another dropping southeast
out of British Columbia. The first wave lifting north is bringing
an influx of subtropical moisture with 700-500 mb specific
humidity values of 6-7 g/kg. This plume will shift northeast
across Colorado through the day. Meanwhile...the northern wave
will provide increasing q-g lift by this afternoon and
evening...the strongest of which will be over the northeast plains
of Colorado extending into the northern High Plains. Finally...a
cold front will drop south across northeast Colorado later tonight
which should bring at least shallow upslope flow.

With regard to the sensible weather highlights...the increasing
q-g lift and deep moisture plume will bring more numerous showers
and storms by this afternoon. Expect the highest coverage in the
mountains where nearly everyone should see some rain by this
evening...while on the plains convection should still be fairly
widespread but limited a bit by a relatively dry and warm
atmosphere below 600 mb. That being said...many times these types
of systems can bring an organized line of showers/storms off the
Front Range so probability of precipitation may need to be raised further into the likely
category should sufficient daytime heating/destabilization occur
ahead of the deep moisture plume.

There will be limited cape of less than 500 j/kg on the plains...so
the risk of severe weather is quite low. Main threat would be
gusty outflow winds along and ahead of storms. Some storms may
produce heavy rain but storms will be moving along at 20-25 knots
so threat of any flooding issues is low as well.

Cold front arrival late this evening to just after midnight will
likely bring shallow upslope and a continued threat or
redevelopment of showers and a few storms. Temperatures turning
cooler as well.

Long term...(monday through saturday)
issued at 326 am MDT sun Jul 5 2015

Overall trend is the same for Monday. A cool Post frontal airmass
will establish itself over the northeast plains. The spatial cross
sections and forecast soundings show some northeasterly upslope winds in
the morning below 700 mb...it weakens and become more easterly in
the afternoon. Highest precipitation coverage will be in and near the Front
Range foothills/Palmer Divide. Precipitable water values still well in excess of
one inch. Due to the increased stability however...will go with
rain showers vs thunderstorms from the urban corridor eastward
Monday afternoon and evening. Highs on Monday still prognosticated to
only warm into the lower 70s...well below normal. In the high
country...better instability with plenty of subtropical moisture
around. Scattered to numerous showers/thunderstorms in the afternoon. The ridge
will be shifted more to the south with a weak west/northwesterly
flow aloft. As a result...some of the storms will produce heavy
rainfall. On Tuesday...there will still be a westerly flow over
Colorado with as ridge to the south and trough to the north. The
surface high will still keep the northeast plains stable through
much of the day. Surface winds more east-southeasterly with some slight
temperature modification. Forecast soundings do show some cape in
afternoon...around 400 j/kg...as highs will be in the middle 70s. As
a result...will go with chance of rain showers with isolated thunderstorms
along the urban corridor. Better thunderstorm coverage will be in the high
country. Tuesday night into Wednesday...the ridge does amplify a
bit over Colorado ahead of a closed low off the central California coast.
Temperatures will below normal but will close in on the 80 degree
mark. Models still show plenty of subtropical moisture around so will
go with chance probability of precipitation across the County Warning Area. The trend of warmer will continue
through the latter part of the week as the highs climb back into
the 80s. The flow aloft will become southwesterly as the trough moves
inland and the ridge axis shifts to the east. Best chance of thunderstorms
will continue to be in the high country at that time...with slight
chance probability of precipitation in the late afternoon/evening time frame across the northeast
plains.

&&

Aviation...(for the tafs through 12z Monday morning)
issued at 326 am MDT sun Jul 5 2015

With the plume of upper level moisture moving across and some
synoptic scale lift noted...thunderstorm coverage is expected to
be higher this afternoon/early evening. This would warrant tempo
thunder and gusty winds from around 21z-01z as a batch of
organized convection should move off the Front Range. Outflow wind
gusts could reach 35-40 knots with relatively dry low levels and
moderate middle level flow. Until then...look for VFR conditions and
fairly normal diurnal wind patterns. Cold front around 06z tonight
will bring another chance of showers and ceilings dropping to
1000-2000 feet above ground level.

&&

Bou watches/warnings/advisories...
none.
&&

$$

Short term...barjenbruch
long term...Cooper
aviation...barjenbruch

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