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

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FXUS63 KEAX 190922

422 AM CDT Tue Aug 19 2014

Issued at 417 AM CDT TUE AUG 19 2014

More nocturnal convection is effecting the region this morning as a
shortwave trough swings east through the northern and central
Plains. The transiting trough has helped focus a modest low level
jet --from southwest at 20 to 30 knots-- across eastern Kansas into
western Missouri. Rustling moisture convergence and isentropic
assent has ultimately forced convection to develop despite the warm
air aloft. Veering jet this morning has already shifted to
prevailing from due west as the parent trough slides slowly into the
western Great Lakes. This resulted in the rapid development of a
broken line of thunderstorms from north to south from northwest
Missouri to the southern border of Kansas as of this writing.

Model guidance has been of little help this morning as even the
hi-res models have struggled to correctly forecast where and when
this potential convection would get started. However, ongoing
activity has been around long enough for some of the hi-res
models to ingest said data and start spitting out more realistic
solutions. To wit, expect the current broken line of storms to push
a bit farther east early this morning but that the activity will
also slowly decrease as it moves away from the best moisture
transport occurring with the low level jet. Do not expect this
activity to persist past sunrise much, and what does persist will
likely be fading away. Anticipate updating POPs several times early
this morning to keep up with the convection location. These early
morning storms will be capable of producing torrential rain, small
hail and locally gusty sub-severe winds.

Another night of potential convection may be in store for later
tonight as the ridge axis to our west shifts northeast, inducing a
fair amount of warm air advection aloft over the Central Plains.
This looks to set up a potential corridor of storm activity again
tonight perpendicular to tonight`s expected southwest low level jet,
roughly along an axis from the northwest corner of Missouri into
central Missouri. Models really advertise this potential developing
after midnight, but thoughts are that warm air advection storms tend
to develop faster than the models forecast. Therefore have slight
chance POPs in the forecast as early as this evening. Shear and
instability both indicate that small hail and locally gusty winds
may be an issue with storms again, but with precipitable water values in
the 1.75 inch range torrential rain will likely accompany all
storms. Wont issue any hydro-watches with this forecast package as
confidence in location and timing are still a bit iffy, but if any
storms can train across the same areas flooding will quickly result
especially across northern Missouri where heavy rains fell this past

Looking forward through the work week, the ridge axis building in
will result in the arrival of the dog-days-of-summer. Hot and humid
conditions, more typical of August than our wonderful bout of cool
temperatures would lead your to believe of late, will continue to
push into the Central Plains through the end of the work week. The
primary effects this has on the forecast is to force potential
convection later in the week to our north. This will leave far
northern Missouri with a fleeting on-again-off-again chance for
storms as activity roles from Nebraska into Iowa, but much of the
rest of Kansas and Missouri will miss out on this precipitation.
What we will get instead is hot and humid conditions with heat index
values likely bubbling up over 100 degrees through the later half of
the work week.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1103 PM CDT MON AUG 18 2014

Operational models cont to try and generate thunderstorms over
northeast Kansas and move them into the terminals btn 09Z-12Z whereas
the hi-res models cont to generate nothing. This conts to lead to
low confidence TAF with VCTS btn 09Z-12Z. Otrw...conds will remain
VFR with sct-bkn cloud btn 5-6kft during the early morning hours
giving way to sct mid level clouds during the morning. Expect just
sct high cirrus tomorrow afternoon and evening. Winds will be lgt and
vrb through the TAF period.




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