Mesoscale Discussion 1800
   NWS Storm Prediction Center Norman OK
   1216 PM CST Sun Nov 15 2020

   Areas affected...western NY...western PA

   Concerning...Severe Thunderstorm Watch 509...

   Valid 151816Z - 151945Z

   The severe weather threat for Severe Thunderstorm Watch 509
   continues.

   SUMMARY...It remains uncertain whether an additional severe
   thunderstorm watch will be needed across western NY and western PA,
   but short-term trends will continue to be monitored.

   DISCUSSION...Widespread measured severe gusts (50-65 kt) are
   occurring across central and northeast OH per recent surface
   observations.  The Cleveland, OH ASOS measured a 62-kt gust at
   1253pm EST.  Surface temperatures in northeast OH range from the mid
   50s F in Ashtabula County to around 60 F in Cleveland.  Temperatures
   in western NY per NY Mesonet site data show temperatures gradually
   warming into the lower 50s.  

   Given trends in recent NAM/RAP forecast soundings being too cool
   compared to observed temperatures in northeast OH, it is reasonable
   to assume a cool bias for western NY.  KBUF VAD is showing 65 kt at
   1 km AGL and 100 kt at 6 km AGL.  The intense wind fields coupled
   with the broken band of storms moving rapidly northeast along the
   I-90 corridor suggest at least an isolated risk for severe gusts and
   wind damage across western NY.  If a brief period (30-60 minutes) of
   cloud breaks can develop ahead of the convective line prior to
   moving into northwest PA, a potentially more widespread threat for
   severe gusts could develop across western NY.

   ..Smith.. 11/15/2020

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

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

   LAT...LON   42477980 43277896 43377781 43067758 41777836 41007877
               40337935 39878024 39988089 40558024 40777961 41777944
               42477980