ZCZC SPCSWOMCD ALL
ACUS11 KWNS 151759 
SPC MCD 151759 
NYZ000-PAZ000-OHZ000-151930-

Mesoscale Discussion 1865
NWS Storm Prediction Center Norman OK
1259 PM CDT Fri Oct 15 2021

Areas affected...northern Ohio...far northwest Pennsylvania and far
western New York

Concerning...Severe potential...Watch possible 

Valid 151759Z - 151930Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms are expected to undergo an increase in
coverage and intensity during the next couple of hours. Isolated
damaging wind should be the main threat, but some hail and a brief
tornado cannot be ruled out. Trends will continue to be monitored
for a possible watch.

DISCUSSION...Showers and a few thunderstorms are in the process of
developing just east of a surface low in northwest OH and farther
east in vicinity of a warm front across northern into far northwest
PA. The warm sector has undergone some destabilization as
temperatures warm through the 70s to near 80 F, but widespread
clouds are slowing this process, and weak mid-level lapse rates
should limit MLCAPE to near or below 1200 J/kg. Effective bulk shear
from 35-40 kt will support some organized storm structures,
including potential for a few rotating updrafts and linear segments
with isolated damaging wind the main threat. Through a brief tornado
cannot be ruled out, low-level hodographs will remain relatively
small which should mitigate the overall tornado threat. Limiting
factor for a more robust severe thunderstorm threat is the somewhat
marginal thermodynamic environment, but trends will continue to be
monitored for signs of storm organization and a possible WW.

..Dial/Grams.. 10/15/2021

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

ATTN...WFO...BUF...PBZ...CLE...

LAT...LON   42317947 41437987 40638147 40538275 40848357 41398317
            41838157 42317947 

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