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ACUS11 KWNS 150205
SPC MCD 150204

Mesoscale Discussion 1717
NWS Storm Prediction Center Norman OK
0904 PM CDT Sat Oct 14 2017

Areas affected...Parts of south/east central Missouri...central and
northeast Illinois...northern Indiana

Concerning...Tornado Watch 501...

Valid 150204Z - 150330Z

The severe weather threat for Tornado Watch 501 continues.

SUMMARY...Thunderstorms may continue to be accompanied by a risk for
potentially damaging wind gusts as the develop eastward late this
evening into the overnight hours.  However, this risk is expected to
become considerably more spotty or localized after 10-11 PM CDT.

DISCUSSION...With weak to negligible mid-level cooling across the
warm sector, the loss of daytime heating is resulting in waning
boundary layer instability across the lower Missouri Valley into the
southern Great Lakes region.  By 03-04Z, this may begin to result in
more rapid weakening convective trends.  Until then, though, the
more vigorous lingering thunderstorm activity remains focused ahead
of the southeastward advancing cold front, and will continue to be
accompanied by a risk for potentially damaging surface gusts. Warm
sector lower/mid tropospheric wind fields continue to strengthen to
40-50+ kt, in response to further surface cyclone development across
Iowa into the Upper Midwest, where a more rapid deepening of the low
center is still expected overnight.  As a result, some risk for
damaging surface gusts may persist beyond 03-04Z in lingering
convection spreading into the lower Ohio Valley/southern Great Lakes
region.  But this likely will become increasingly localized in

..Kerr.. 10/15/2017

...Please see for graphic product...


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