Storm Prediction Center Mesoscale Discussion 2220

   Mesoscale Discussion 2220
   NWS Storm Prediction Center Norman OK
   0513 PM CDT Thu Sep 03 2026

   Areas affected...portions of southeastern Pennsylvania

   Concerning...Severe Thunderstorm Watch 649...650...

   Valid 032213Z - 032345Z

   The severe weather threat for Severe Thunderstorm Watch 649, 650
   continues.

   SUMMARY...An organizing MCS will yield a greater risk for severe
   wind gusts across portions of southwestern Pennsylvania over the
   next 1-2 hours.

   DISCUSSION...Regional radar imagery depicts an organizing MCS across
   portions of western Pennsylvania, with volume scans over the past 30
   minutes from KPBZ depicting embedded velocities up to 65 kts at 600
   ft AGL. Numerous reports of wind damage have been noted with this
   complex, including downed trees and power lines, with a 62 mph wind
   gust also recently measured at KHLG in far northern West Virginia.
   The downstream environment remains favorable for damaging/severe
   wind gusts, with steep low-level lapse rates (7.5-8.0 K/km),
   moderately strong instability (2500-3000 J/kg MLCAPE), and around
   30-40 kts of effective shear in place, as sampled by the 18z PIT
   observed sounding and recent objective analysis. Given this
   environment and the organizing MCS, a locally greater risk for
   damaging/severe wind gusts is likely to accompany this system as it
   progresses east-southeastward across portions of southwestern
   Pennsylvania.

   ..Chalmers.. 09/03/2026

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

   ATTN...WFO...CTP...PBZ...

   LAT...LON   40807971 40837951 40837933 40597877 40387844 40087843
               39837880 39857945 40038003 40318051 40428054 40668018
               40737995 40807971 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN