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Area forecast discussion 
National Weather Service Pueblo Colorado
237 PM MDT sun Aug 2 2015

Short term...(this evening through monday)
issued at 235 PM MDT sun Aug 2 2015

..heavy rain possible over the mountains tonight...
..Another round of storms tomorrow...some on the strong side...

Main concern for the short term is potential for flash flooding over
the mountains through tonight. Scattered to numerous showers and storms
have already developed this afternoon...and as a strong shortwave
now moving through Arizona and Utah continues to translate to the NE this
evening...the threat for locally heavy rainfall will persist.
Latest guidance shows the associated upper low over Utah moving into
northwest Colorado by 12-15z Monday morning. Am particularly concerned by the
latest high res WRF and hrrr runs...which both show a strong band
of heavy precipitation moving through SW-central Colorado between 03z and 09z
tonight. This would coincide with strongest upper forcing from the
short wave. In coordination with kgjt and kabq have expanded our
Flash Flood Watch for the San Juans to include the rest of the
Continental Divide...along with the sangre Delaware cristo range...through 09z
tonight. This may have to be extended slightly if the banded heavy
precipitation gets a delayed start...but there is still some uncertainty
on how intense the precipitation will be...especially since the strongest
forcing will occur during the overnight hours when convection is
generally less intense. Nevertheless...anyone planning on being in
or traveling through the mts this evening and overnight needs to be
aware of the potential for flood-producing rains...which could
lead to sudden small stream rises...flooded roadways...and mud or
rock slides in the steeper terrain.

Tomorrow...the upper wave will continue to move to the NE during the
day...into southern Wyoming by 00z Tuesday. This will bring several more rounds of
convection to the area...particularly over the higher terrain. Low
level moisture will also increase over the plains. Along with
increased shear...this will raise the threat of some strong to
possibly severe storms over the area. It looks like the greatest
instability will be over the southeastern plains generally south of hgwy 50
and east of I-25...and this is where the strongest storms likely will
be during the afternoon. Lower temperatures aloft along with increased low level
moisture and precipitation/clouds will hold high temperatures a good 5-10 degrees
below the high temperatures from today...so will see mainly temperatures in the
70s and 80s Monday afternoon. Rose

Long term...(monday night through sunday)
issued at 235 PM MDT sun Aug 2 2015

Monday night...as an upper disturbance moves northeastward out of southeastern
Colorado and an upper trough moves northward into Wyoming...the isolated to scattered precipitation
across the forecast should come to an end around midnight. On Tuesday an
upper ridge axis will lie from Arizona into the Great Basin region...
resulting in west to northwest flow aloft over the forecast area. The latest
run of the NAM and GFS shows drier conditions for Tuesday...with mainly
just some isolated precipitation chances. Tuesday night surface high pressure backs into
eastern Colorado and is expected to bring increasing low level moisture and the
potential for some low clouds. As a result...the NAM prints out the
potential for some light precipitation over the far southeastern plains late Tuesday night
and early Wednesday morning...however will leave the forecast dry for now.

On Wednesday the upper ridge axis shifts eastward over Colorado with relatively dry
conditions expected through much of the day with mainly just some
isolated precipitation over and near the mountain areas. However a weak disturbance
may round the top of the ridge and move through eastern Colorado in the evening
hours to help kick off some convection across the plains. On Thursday the
upper ridge gets flattened across the forecast area as a shortwave
trough moves through Montana Wyoming and northern Colorado. Only some isolated precipitation is expected
Thursday afternoon...but then as that disturbance moves off into the
plains states the European model (ecmwf) is still showing an mesoscale convective system developing and
affecting portions of eastern Colorado by Thursday evening.

Friday an upper trough is expected to move over California...with an upper ridge being
over Colorado. Moisture still looks to be somewhat limited during the
day...with maybe just some isolated to scattered precipitation over the forecast area.
Then Friday night and Sat as that upper trough moves east-northeastward
into Idaho and Utah...monsoon moisture is expected to be drawn northward into
western Colorado again which will increase the chances for precipitation...especially
over the mountains and high valleys. As the upper disturbance moves eastward
across Montana and Wyoming Sat night...precipitation is expected to spread across the eastern
Colorado plains. Then by sun it looks like the forecast area will again be
cutoff from the monsoon moisture...leading to drier conditions again.

&&

Aviation...(for the 00z tafs through 00z Monday evening)
issued at 235 PM MDT sun Aug 2 2015

Main concern continues to be storms this afternoon and this evening. At
kcos and kpub this threat will be highest through around
03z...although isolated storms will be possible through tonight. At
kals...several rounds of modt to heavy precipitation will be possible
through tonight. Could see several rounds of MVFR to occasionally
IFR develop for the San Luis valley due to low ceilings and/or visible. As
an upper level disturbance continues to move northeastward from Utah into northwest Colorado
and SW Wyoming...this will keep the threat of precipitation and low ceilings going
through Monday morning for much of southeast Colorado. Storms could redevelop Monday
afternoon before dissipating from SW to NE Monday evening. Rose

&&

Pub watches/warnings/advisories...
Flash Flood Watch through late tonight for coz058-060-061-063-
066>068-072>075.

&&

$$

Short term...rose
long term...28
aviation...rose

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