Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 110501

1201 AM CDT Fri Jul 11 2014

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Friday)
Issued at 331 PM CDT THU JUL 10 2014

Main question again is the chance for thunderstorms. Mid level
baroclinicity remains strong with 12Z obs showing 700MB temperature
gradient around 7C west to east across Nebraska and Kansas. An upper
level wave moving east across the Northern Plains tonight will aid
in increasing southwest mid to low level flow over the Central
Plains through the night and into Friday for moderate isentropic
lift to form on the 310 and 315K theta surfaces. Moisture profiles
slowly increase as this occurs with a few hundred J/kg of elevated
CAPE developing around 12Z for far eastern locations. A lack of
large scale forcing and any focusing mechanism as well as somewhat
limited moisture keeps precip chances low. The warm air advection
will bring 850MB temps up 5-8C for a much warmer day Friday with
highs still on target for the middle to upper 90s, and heat index
values near to slightly above these levels.

.LONG TERM...(Friday Night through Thursday)
Issued at 331 PM CDT THU JUL 10 2014

Models continue to show the synoptic pattern amplifying with a
closed upper low (not the polar vortex as it`s origins are from
the northeastern Pacific) moving south into the Great Lakes early
next week.

For the weekend and into Monday, precip chances will be hard to
rule out since some sort of boundary will be in the area with
reasonable instability. Overall forcing continues to look limited
as mid level ridging holds on to the south while the closed low
remains well north of the area. Because of this the prospects for
widespread rainfall seem low with precip being more hit or miss.
The initial front is expected to move into the area late Saturday
afternoon and Saturday evening as the upper ridge break down
overhead. The main push of cold air is expected late Monday and
Monday night as a trough axis with the closed low rotates north to
south with the closed upper low. It is these times, when the fronts
are moving through, that the forecast will show a chance for
precip. Models show marginal deep layer shear through the weekend
so organized severe weather seems to be a low probability at this

The deep upper low propagating south into the Great Lakes is
expected to bring an anomalously cold airmass south from Canada
and we may threaten a couple records Tuesday and Wednesday. With a
good consensus from the model guidance showing the colder airmass,
have continued to trend temps cooler for Tuesday and Wednesday
thinking lows in the 50s and highs in the 70s are likely. The
other trend in the models is to move the main front through the
area a little faster and push it south by Tuesday morning. With
this in mind, have lowered POPs for Monday night and removed the
small chance POPs for Tuesday. Wednesday and Thursday should be
dry as the surface high pressure system remains over eastern KS
through Thursday. Tuesday and Wednesday should be the coolest days
of the week as the center of the surface ridge builds into the
area. Then temps should moderate for Thursday with the potential
for some southerly winds to return across north central KS on the
back side of the surface ridge.


.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1141 PM CDT THU JUL 10 2014

VFR conditions expected through the TAF period. Very small chance
of a TS impacting TOP or FOE between 08Z and 12Z, but should stay




LONG TERM...Wolters
AVIATION...Barjenbruch is the U.S. government's official web portal to all federal, state and local government web resources and services.