Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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000
FXUS63 KEAX 241749
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1249 PM CDT WED AUG 24 2016

.Discussion...
Issued at 429 AM CDT WED AUG 24 2016

It`s looking stormy for the next few days across northern Missouri.
Water vapor imagery this morning shows a large trough spinning it`s
way east across the Canadian Plains, with the resulting lee side
surface trough forming a frontal boundary oriented north-south
across the east edge of the Dakotas into eastern Nebraska this
morning. Storms struggled to get going locally during the day, but
with the setting sun the low level jet ahead of the frontal boundary
finally found enough focus to generate some storms in central Kansas
and southeastern Nebraska. These two areas of convection moved east
early this morning, with the remnants of the Kansas storms
interacting with a modest outflow that the southeast Nebraska
convection dropped, which is now helping produce an area of
widespread shower activity heading south southeast through northwest
Missouri early this morning.

Today and Tonight...Morning storms will likely blow themselves apart
by sunrise today as there does not appear to be much fueling this
activity besides the nocturnal jet interacting with the advancing
outflow boundary. Therefore, have trimmed POPs across the forecast
area for the morning hours, focusing categorical POPs across far
northern Missouri in the late afternoon and overnight hours as a
frontal boundary sags south and stalls. This may allow storms to
start redeveloping in the vicinity of the front later today, with
the NAM advertising storms again by the early to mid-afternoon hours.
However, thoughts are that the NAM is a little quick with it`s storm
development and that the GFS might have a slightly better handle on
the afternoon evening activity with the later onset of storms along
the front. However, both models advertise that the larger prevailing
flow from the moisture plume --noted arching from western Texas into
the Central Plains-- will run parallel to the stalled boundary,
which will likely result in training storms in the vicinity of the
boundary tonight. And, with precipitable water values expected to be
running around 2 inches this evening, these storms will be efficient
rain makers. Therefore have gone ahead and issued a flash flood
watch for northern Missouri of the overnight hours. But what about
the severe threat? CAPE values in excess of 2000 J/KG and will
coincide with increasing shear values late this afternoon and evening
as the front stalls in northern Missouri, with 0-6 KM shear values
going from less than 20 knots to around 40 knots this evening in the
vicinity of the front. Therefore, in addition to the torrential rain,
there looks to be a threat of strong to severe storms which might be
able to produce large hail and damaging winds tonight.

Thursday on through the weekend...while tonight might be the wettest
period of the next few, it likely wont be the only wet period. The
stalled frontal boundary tonight is expected to wash out and/or move
back north as a warm front starting late Thursday/early Friday as
the larger synoptic flow keeps the upper level flow across our
section of the Plains States oriented from the southwest. As a
result, models continue to advertise many potential rounds of rain
late this work week into the weekend. The general trend has activity
most notable near the Iowa border, but thus far all locations of
northern Missouri look to be threatened by rain at some point through
the weekend.

&&

.Aviation...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1239 PM CDT WED AUG 24 2016

Showers with embedded thunder to start the TAF period could directly
impact the area terminals through the mid-afternoon hours. After this
initial round, anticipating a brief break before more robust
thunderstorms develop and move into the area later this evening into
the overnight hours. With this activity, moderate to heavy rainfall
will be possible, reducing visbys. Additional hazard may include
gusty winds with some of the stronger storms that may develop, and
cannot rule out the potential for said strong storms to contain hail.
Convection is currently looking to tamper off by around dawn Thursday
morning with winds shifting from out of the NW behind a passing
frontal boundary.

&&

.EAX Watches/Warnings/Advisories...
KS...Flash Flood Watch from 7 PM CDT this evening through Thursday
     morning for KSZ025-102.

MO...Flash Flood Watch from 7 PM CDT this evening through Thursday
     morning for MOZ001>008-011>017-020>025-032-033.

&&

$$

Discussion...Cutter
Aviation...lg



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