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

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FXUS63 KEAX 221714
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1214 PM CDT Tue Aug 22 2017

.Discussion...
Issued at 332 AM CDT TUE AUG 22 2017

A strong LLJ of 40-45kts developed ahead of a cold frontal boundary
over southern NE/IA shortly after sunset setting off a line of
strong to severe thunderstorms over the KC Metro area.  As seen
during the eclipse a large amount of mid and upper level moisture
had moved into the area this morning from a tropical connection seen
on WV all the way back down into Mexico.  This helped to prime the
area with PWAT values 2"+ and the LLJ and weak WAA allowed MUCAPE
values over 1000J/kg with storm motion along the prefrontal trough
on the convergent zone of the LLJ. Training storms developed with
2- 3" per hour rates at first that have dropped down to 1-2"
rates currently. Multiple water rescues and road closures and
flooding lead to a Flash Flood Emergency issued for the KC Metro
overnight. A large swath of 4" of precip fell over the KC Metro
with some 6-8" totals in western Jackson county leading to Indian
Creek reaching near or over record levels for the second time in a
month. An outflow boundary from the convection along the cold
frontal boundary was sent through the area helping to intensify
the convection, but also helped to stabilize the back side of
this complex of storms. This cold front is expected to push south
quickly this morning clearing out all precipitation and cloud
coverage around sunrise. Winds will shift to the north behind the
frontal boundary and increase it the afternoon to 10-15mph.
Precipitation should be out of the CWA by noon with strong high
pressure building into the area on the backside.

A large upper level ridge will build into the Rockies starting
Tuesday as the trough over the Great Lakes pushes east.  This
ridging will advect in very stable dry air over the region setting
up one of the nicest weeks of the summer.  High temperatures will
remain in the lower 80s with no precipitation expected through
the work week. The ridge starts to break down over the weekend
leading to some chances of precipitation but nothing very
impactful is showing on the current extended models. One thing to
note is that the GFS, Canadian, and ECMWF are showing a strong
tropical system going into southern TX on Saturday and depending
on how far west it lands the moisture plum could make it to our
area.

&&

.Aviation...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1214 PM CDT TUE AUG 22 2017

A surface high is building in behind the front that pushed through
Monday night, pushing storms and cloud cover to the south. Winds
will be light and from the north as a result. Fog may be an issue
Wednesday morning, but have not added that into the TAF yet as it
is way out at the end of the period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

Discussion...Barham
Aviation...Cutter


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