Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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440
FXUS65 KBOU 232200
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
400 PM MDT SAT JUL 23 2016

.SHORT TERM...(This evening through Sunday)
Issued at 237 PM MDT Sat Jul 23 2016

So-called cold front dropping past Longmont and Greeley at this
time. The combination of the new airmass and some thunderstorms
behind the front are dropping temperatures down to around 90.
Previous thinking had been that the drier air behind the front
would not support storms, but this is not the case as there
appears to be some forcing aloft stretching from north of Grand
Junction toward Cheyenne and the slight cooling/drying is not
enough to suppress the storms. So the main change to the forecast
was to include some low POPs across northeastern Colorado and
increase clouds through the night. Still expecting not much rain
with most of the storms, and localized gusty winds.

Sunday looks like our day 2 scenario, and at first appeared to be
more active. However there is only slight cooling aloft and the
incoming air is cooler but still fairly dry at first. We may
recover to a temp of 90/dew point of 50 in Denver by the end of
the day, but that is still not enough to generate surface based
convection. Suspect it will wind up being like the last couple of
days where the activity was more toward evening and really
depended on storms originating over the mountains and boundary
collisions on the plains to force convection through a weak cap.

.LONG TERM...(Sunday night through Saturday)
Issued at 237 PM MDT Sat Jul 23 2016

Weak jet dynamics and upslope flow will help scattered
thunderstorms to continue Sunday evening, mainly along and south
of I-70 and some possibly strong, heading east towards Kansas.
The main hazards will be strong outflow winds, some hail and
lightning. A few storms may last after midnight over the far eastern
plains.

The upper high will move north over the state to bring warmer and
drier weather on Monday. Most convective activity will remain over
the higher terrain and south of I-70, with gusty outflow winds as
shown by the inverted-v forecast soundings.

A weak disturbance and cool front will move over the area Tuesday
which should stabilize the northern areas of the forecast area and
produce convection over the south. Temperatures will remain
similar to Monday`s readings.

Dry northwest flow aloft is expected for Wednesday for a warm and
dry day. A shortwave in the flow Thursday will send down another
cold front for upslope flow through Friday. Expect cooler
temperatures and a chance of storms across the forecast
area, mainly east of the divide.

The upper ridge will then build north again over the four corners
area to bring warmer and drier conditions.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 237 PM MDT Sat Jul 23 2016

VFR through Sunday. Isolated thunderstorms will likely produce a
wind shift or two at the Denver area terminals through about 02Z.
Gusts up to 30 knots are possible, but the speeds will likely be
lower. Similar coverage and threats are expected late Sunday
afternoon into the evening.

&&

.BOU Watches/Warnings/Advisories...
None.
&&

$$

SHORT TERM...Gimmestad
LONG TERM...Kriederman
AVIATION...Gimmestad



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