Mesoscale Discussion 1397
   NWS Storm Prediction Center Norman OK
   1132 PM CDT Sat Jun 21 2025

   Areas affected...North-central Upstate New York

   Concerning...Severe potential...Watch possible 

   Valid 220432Z - 220630Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Some risk for large hail and damaging winds may accompany
   a cluster moving into Upstate New York out of Ontario. Given limited
   spatial extent of a favorable environment, the need for a watch is
   not clear. Trends will continue to be monitored.

   DISCUSSION...A cluster of storms continues to move southeastward
   through southern Ontario towards Upstate New York. This cluster is
   moving at about 40 kts. Storms initially developed on the southern
   flank of a compact shortwave trough and are now being further
   maintained by a 50 kt low-level jet (evident on the KBUF VAD).
   Regional observed soundings from this evening show a fairly sharp
   gradient in mid-level lapse rates with BUF showing near 8 C/km and
   ALB showing only around 5 C/km. A belt of strong northwesterly flow
   aloft is promoting over 50 kts of effective shear.

   Some model guidance from earlier this evening showed some potential
   for a greater expansion of convection farther east. This, however,
   should be limited by rapidly decreasing buoyancy. It is more likely
   that the strongest activity remains on the western flank of the
   cluster as mid-level lapse rates and elevated buoyancy will slowly
   increase with time from the northwest. Long hodographs along with
   the steep mid-level lapse rates will mean some risk of large hail.
   Damaging winds remain possible as well, but this may only be an
   isolated threat given at least some low-level CIN exists and
   potential influence from cooler lake boundary layer.

   The need for a watch is not certain given the limited area of
   greater instability downstream of the current activity and that
   convection may outpace the slow increase in buoyancy through
   tonight. Trends will be monitored over the next few hours.

   ..Wendt.. 06/22/2025

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

   ATTN...WFO...BTV...ALY...BGM...BUF...

   LAT...LON   43027692 42947763 43367831 44027842 44357698 44577584
               44517501 44117472 43427510 43237577 43027692 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN