Mesoscale Discussion 1240
   NWS Storm Prediction Center Norman OK
   1118 AM CDT Thu Jul 16 2020

   Areas affected...Eastern OH...Northern WV Panhandle...Western PA

   Concerning...Severe potential...Watch likely 

   Valid 161618Z - 161815Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorm coverage is expected to increase across
   eastern OH, western PA, and far western NY over the next few hours.
   Conditions are favorable for some severe thunderstorms, with
   damaging wind gusts as the primary threat. A tornado or two is also
   possible.

   DISCUSSION...Recent surface analysis places a low over far southern
   Lower MI, with a cold front extending back south-southwestward
   through western OH and southern IN. A pre-frontal trough also arcs
   eastward and then southwest across OH. Some deep cumulus has been
   noted in the vicinity of this pre-frontal trough over the past half
   hour. Deeper cloud billows have also been noted across eastern OH
   and into western PA, where air mass destabilization is occurring
   amid filtered daytime heating and low-level moisture advection. 

   Expectation is destabilization and forcing for ascent along the two
   surface boundaries (augmented by ascent attendant to low-amplitude
   shortwave trough) to persist, resulting in scattered thunderstorm
   development from eastern OH into western PA. Enhanced low-level flow
   throughout the eastern periphery of the shortwave trough will
   support moderate low-level shear and the potential for a few
   stronger, more organized updrafts capable of damaging wind gusts and
   perhaps even tornado or two. 

   The best overlap between ongoing storms and the enhanced low-level
   flow is anticipated over northwest PA and far western NY. Some
   interaction with the warm front is also possible across western NY.
   Damaging wind gusts remain the primary severe threat, but these
   conditions lead to a relatively greater tornado potential in this
   area.

   ..Mosier/Hart.. 07/16/2020

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

   ATTN...WFO...BUF...CTP...PBZ...RLX...CLE...ILN...

   LAT...LON   40108297 41388240 41708134 42377947 43167819 42767768
               41027845 39817916 39328254 40108297