Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 180405

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1005 PM MDT SUN JUL 17 2016

Issued at 1000 PM MDT Sun Jul 17 2016

Strong west bound outflow from mesoscale storm complex on the
northeast plains is now colliding with the drier downslope flow
off the Front Range. This collision is currently taking place
along the U.S Hwy 85 corridor extending south from central Weld
County to just southeast just of Denver. This moist and unstable
east- southeast inflow is expected to persist for at least the
least couple of hours...potentially resulting in single to multi-
cell storm growth along this convergence zone. Heavy rainfall and
frequent lightning rain concerns at this time...but would not rule
out large hail and a brief tunnel or tornado. It is possible this
latest batch of storms could drift west over the Denver metro area
and southern portions of the I-25 urban corridor in the next hour
or so. Otherwise...this lingering moisture banked up along the
Front Range will result in areas of stratus and possibly some fog
towards morning. Zone forecast update will be out momentarily.


.SHORT TERM...(This evening through Monday)
Issued at 213 PM MDT Sun Jul 17 2016

for this evening...the northeast corner dewpoints are still in the
upper 50s and lower 60s. caps on all models are 2500+ with low
cins. several models suggest a southeast moving supercell
clipping the northeast corner. This already is reflected in grids.

After a lull late tonight and early monday...monday pm looks
capped on the northeast plains...with the best opportunity of
convection over the higher terrain of the palmer divide...cheyenne
ridge and the mountains and foothills. this is also already
reflected in previous no changes. I did raise max
temps a degree in eastern colorado due to higher guidance numbers.

.LONG TERM...(Monday through Saturday)
Issued at 241 pm MDT Sun Jul 17 2016

Models keep the upper ridge centered over Oklahoma Monday night
through Wednesday night. There is weak southwesterly flow aloft
for the CWA all five periods. There is no synoptic scale energy
noted on the QG Omega fields through 12z Thursday morning. Models
show a fairly weak low level pressure gradient Monday night so
normal drainage wind patterns should prevail. There should be some
easterly winds Tuesday and Wednesday, with normal drainage flow
during the night times. Models have quite a bit of mid and upper
level moisture for the CWA through Thursday morning. The
precipitable water values are in the 0.70 to 1.50 inch range
Monday evening. They are in the 0.50 to 1.40 inch range Tuesday
and Wednesday. Models have plenty of CAPE over all the CWA through
the periods, with the highest values over the mountians and
foothills during the afternoons and evenings. We should have
decent thunderstorms coverage in the mountians for the next
several days, but still not great out on the plains. The plains
could see 30% pops late day Monday and Tuesday. Heavy rain could
be an issue Monday evening. For temperatures, Tuesday`s highs
will be 1-3 C warmer then Monday`s highs. Wednesday`s highs will
be 1-2 C warmer than Tuesday`s. For the later days, Thursday
through Sunday, models keep the upper high centered southeast of
the CWA, but the upper ridge flattens out somewhat Friday into the
weekend. There will still be some mid and upper level moisture to
move across the CWA, but less by Saturday and Sunday.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1000 PM MDT Sun Jul 17 2016

Thunderstorms forming rapidly along a wind convergence boundary
extending south from west central Weld county through central
Adams and Arapahoe counties just east of Denver. This boundary
could shift far enough west in the next hour or two resulting in
thunderstorm development in the Denver metro area. Heavy
rain...strong gusty winds and lightning will be the main threats
from these storms should they form. However..can not rule out
hail. Most of the this storm activity should dissipate or move
well east of the metro area by midnight. However...lingering
moisture produced by this convection is expected to produce areas
of low clouds/stratus along the front Range later tonight. Denver
airports particularly KBJC and KDEN could see cigs lowering below
5000 feet after 09z tonight and even as low as 3000 feet agl
towards 12z. The low clouds in the metro area are expected to lift
and move out by around mid-morning. As for winds...variable winds
will dominate through midnight...then go southeasterly for a few
hours after midnight then gradually turn northerly towards
morning which is expected to move the low clouds in.


Issued at 213 PM MDT Sun Jul 17 2016

tomorrow will be the first of several days of monsoon moisture
with scattered showers and thunderstorms over the higher terrain.
winds will be light and dewpoints the overall threat
of large fires will be reduced starting tomorrow. If we can
moisten the fuels the next few days that will also reduce the fire


.BOU Watches/Warnings/Advisories...


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