Storm Prediction Center Mesoscale Discussion 1409

   Mesoscale Discussion 1409
   NWS Storm Prediction Center Norman OK
   0912 PM CDT Tue Jun 30 2026

   Areas affected...2portions of northern New York

   Concerning...Severe potential...Watch unlikely 

   Valid 010212Z - 010415Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Ongoing convection across southern Ontario will spread
   southeastward into northern New York prior to midnight, with some
   potential for isolated damaging wind gusts. Watch issuance is not
   anticipated.

   DISCUSSION...A linear MCS with a rear inflow jet and developing
   bookend vortex (per recent radar imagery from KTYX) is currently
   progressing south-southeastward across far southern Ontario in
   tandem with a subtle mid-level perturbation rounding the northern
   periphery of an upper-level ridge centered over Tennessee/Kentucky.
   Expectation is for this activity to continue to evolve
   south-southeastward amid broad northwesterly mid-level flow and
   along a surface buoyancy/theta-e gradient. Around 40 kts of
   effective shear should continue to promote some organization with
   this MCS; however, cooling surface temperatures and lingering
   low-level stability in the wake of prior convection are expected to
   largely temper the severe threat accompanying these thunderstorms.
   Nevertheless, isolated damaging wind gusts and perhaps an instance
   or two of marginally severe hail may be possible with the strongest
   cores, particularly along the western edge of the cluster where
   available buoyancy will be greater. Trends will continue to be
   monitored, but watch issuance appears unlikely at this time owing to
   the expected limited severe threat magnitude.

   ..Chalmers/Thompson.. 07/01/2026

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

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

   LAT...LON   45037526 45117495 45107460 44987443 44697432 44317442
               44007465 43817492 43647545 43527605 43617665 43807705
               44027727 44197729 44237704 44447622 44657582 45037526 

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