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

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000
FXUS63 KEAX 252315
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
615 PM CDT Tue Jul 25 2017

.Discussion...
Issued at 330 PM CDT TUE JUL 25 2017

Short term concerns across the area stem from warm and muggy
conditions leading to heat indices in the 100 to 106 range this
afternoon. Mid level ridging over the area is the dominant feature
responsible for these conditions. Surface dewpoints in the lower
to middle 70s combined with the temperatures in the lower to
middle 90s and little wind have created these uncomfortable
conditions.

For Wednesday there will be a slight break down and flattening of
the mid level ridge as a shortwave trough kicks through the area.
There could be multiple chances for rain through the day on
Wednesday as good isentropic ascent within a warm air advection
regime ahead of the trough forms some early to mid morning showers
and thunderstorms across northern Missouri. High condensation
pressure deficits in the low levels and model soundings with high
T/Td spreads below 8000 feet indicate that cloud bases will
likely be rather high with this morning activity, which may cut
down on widespread amounts. The best chance for this activity will
be across far northern Missouri, with tapering off further south
along the Missouri River. The better chance for widespread
moderate to heavy rain will come later in the afternoon to evening
when the main impulse associated with the aforementioned shortwave
trough approaches the area. Expect a messy convective mode with
this afternoon activity, which should see pockets of strong to
severe activity, considering MU CAPE in the 2000 to 3000 J/kg
range and deep layer shear values between 30 and 40 kts. Hail and
wind would be the primary concerns with this afternoon/evening
activity on Wednesday. While tornado concerns will be rather
minimal for a couple reasons, an inverted-V type sounding may
produce predominantly outflow storms. That being said, good low
level turning and LCL`s around 5000-6000 feet will not completely
rule out an isolated tornado with this afternoon activity. Cloud
cover and cooling from the morning round of storms may mitigate
some of the afternoon destabilization further north, but even
brief breaks in the clouds will allow for rapid destabilization
for the afternoon round. Flash flooding will be possible, but
probably not likely on a widespread basis with this activity
given high PWAT values of 2.25" to 2.50", which will yield very
efficient rain rates, but flash flood guidance across northern
Missouri for 3 hourly rain rates is around 3 to 3.5 inches.

Areas along and south of Interstate 70/Missouri River should stay
relatively cloud free, which will allow for another day of heat
advisory conditions across that area. Should a few breaks in the
cloud further north form then areas north of the MO River may need
to be included in the advisory, but given the uncertainty with
cloud cover and rain along HWY 36 and areas north have decided to
withhold a heat advisory for that area for now. Once the cold
front clears the area by Thursday expect a fairly pleasant end of
the week and weekend with temperatures in the 80s and mostly dry
conditions.

&&

.Aviation...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 615 PM CDT TUE JUL 25 2017

VFR conditions are expected to persist through the night; then,
convection currently in southeast SD and north central NE may
drift into portions of northeast KS and northwest MO after
sunrise as it dissipates, creating a window for possible showers
or thunderstorms after 15z. Another round of storms is possible
just beyond the end of the TAF period, but much of the afternoon
should be VFR even if the morning round does occur.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory until 8 PM CDT Wednesday for KSZ025-057-060-
     103>105.

     Heat Advisory until 8 PM CDT this evening for KSZ102.

MO...Heat Advisory from noon to 8 PM CDT Wednesday for MOZ030-031-
     038>040-044>046-054.

     Heat Advisory until 8 PM CDT Wednesday for MOZ028-029-037-043-
     053.

     Heat Advisory until 8 PM CDT this evening for MOZ001-011-020.

&&

$$

Discussion...Leighton
Aviation...Laflin



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