ZCZC SPCSWOMCD ALL
ACUS11 KWNS 110746 
SPC MCD 110746 
OHZ000-INZ000-110845-

Mesoscale Discussion 2012
NWS Storm Prediction Center Norman OK
0146 AM CST Sat Dec 11 2021

Areas affected...central into northern IN and western OH

Concerning...Tornado Watch 557...560...

Valid 110746Z - 110845Z

The severe weather threat for Tornado Watch 557, 560 continues.

SUMMARY...Sporadic strong wind gusts and/or a tornado remain
possible across parts of central Indiana into western Ohio the next
few hours.

DISCUSSION...Strong storms continue tonight from roughly Auglaize
County in western Ohio to Knox County in west-central Indiana. Much
of this area remains within a weakly unstable (100-500 J/kg MLCAPE)
airmass. However, strong vertical shear remains present, resulting
in semi-organized line segments. Low-level shear also remains
favorable for rotation within cells and/or mesovortices. The maximum
relative threat will likely be confined to parts of central Indiana
over the next few hours where instability is greatest. Surface
dewpoints decrease into the upper 50s with northward extent, and a
large area of moderate rainfall has overspread much of western into
central Ohio, resulting in boundary-layer stabilization. As such,
the severe threat should remain confined within WW 557 (which has
been locally extended a couple of hours) and WW 560, and a
downstream watch into central OH is unlikely.

..Leitman.. 12/11/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...ILN...LMK...IWX...IND...

LAT...LON   38738605 38918518 39288450 39728407 40498395 40658402
            40728422 40688469 40608492 40368553 40168584 39048705
            38758724 38648717 38608696 38658651 38738605 

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