ZCZC SPCSWOMCD ALL
ACUS11 KWNS 141812 
SPC MCD 141812 
MIZ000-OHZ000-INZ000-142015-

Mesoscale Discussion 1744
NWS Storm Prediction Center Norman OK
0112 PM CDT Tue Sep 14 2021

Areas affected...Southern Lower Michigan and northern Indiana

Concerning...Severe potential...Watch possible 

Valid 141812Z - 142015Z

Probability of Watch Issuance...60 percent

SUMMARY...Storm coverage will likely begin to increase in the next
1-2 hours across parts of central/southern Lower Michigan into
northern Indiana. Damaging wind gusts and isolated large hail will
be possible. A watch is possible by 3-4 PM EDT.

DISCUSSION...Showers and isolated, weak thunderstorms have begun to
develop ahead of the cold front in central/southern Lower Michigan.
Given the uncapped boundary layer, greater convective activity is
expected to occur within the next 1-2 hours as the front continues
to push southeast and mid-level ascent continues to increase across
the Upper Midwest. The main shortwave trough continues to move
northeast into Canada. The strongest shear is expected to exist in
relative close proximity to the front this afternoon. MLCAPE already
around 2000 J/kg will support scattered organized storms/line
segments capable of damaging wind gusts and isolated large hail.
Current visible satellite trends and model guidance would suggest
that the primary severe threat will initiate out of the deepening
cumulus line near and east of Grand Rapids. A watch is possible by
3-4 PM EDT.

..Wendt/Thompson.. 09/14/2021

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

ATTN...WFO...DTX...APX...IWX...GRR...LOT...

LAT...LON   43858442 44038343 43568287 42508324 41618411 40788530
            40848629 41188692 41618696 42408593 43318489 43858442 

NNNN