ZCZC SPCSWOMCD ALL
ACUS11 KWNS 130208 
SPC MCD 130208 
NYZ000-NJZ000-PAZ000-DEZ000-130315-

Mesoscale Discussion 1507
NWS Storm Prediction Center Norman OK
0908 PM CDT Thu Aug 12 2021

Areas affected...eastern PA

Concerning...Severe potential...Watch unlikely 

Valid 130208Z - 130315Z

Probability of Watch Issuance...20 percent

SUMMARY...Cluster of storms ongoing across central PA may pose a
risk for damaging wind gusts for a few more hours before weakening
this evening.

DISCUSSION...As of 0150 UTC, regional radar imagery showed a line of
strong thunderstorms across north-central PA moving east at 45 mph.
Associated with a large band of storms that has recently weakened
farther west, some resurgence has been noted with the lead cluster
west of Scranton, PA. Recent IR imagery showed a localized area of
cooling cloud tops indicating some additional storm
development/strengthening may briefly be possible over the next
couple of hours. Ahead of the line, SPC mesoanalyis indicates an
unstable environment is in place with 2500-3000 J/kg of MLCAPE.
However, convective inhibition is also rapidly increasing as surface
temperatures cool. Vertical shear while not strong at 25 kts is
oriented perpendicular to the motion of the cold pool supporting
strong convergence along the leading edge. Thus, it appears possible
that some severe risk in the form of damaging wind gusts may
continue for a few more hours before nocturnal stabilization
diminishes the threat.

..Lyons.. 08/13/2021

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

ATTN...WFO...OKX...PHI...BGM...CTP...

LAT...LON   40327746 41797639 41887542 41637448 41107439 40537452
            40097477 39907494 39827543 39857627 39877706 40327746 

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