Storm Prediction Center Mesoscale Discussion 1874

   Mesoscale Discussion 1874
   NWS Storm Prediction Center Norman OK
   0127 PM CDT Fri Aug 09 2024

   Areas affected...Portions of southeastern NY...western MA...and
   southern VT

   Concerning...Tornado Watch 617...

   Valid 091827Z - 092000Z

   The severe weather threat for Tornado Watch 617 continues.

   SUMMARY...Within Tornado Watch 617, a potentially favorable corridor
   for a couple tornadoes is evident from southeastern NY into western
   MA and southern VT this afternoon.

   DISCUSSION...Latest visible satellite imagery indicates filtered
   diurnal heating (temperatures climbing into the upper 70s/lower 80s)
   within small cloud breaks in the vicinity of an east/west-oriented
   warm front moving slowly northward across southeastern NY to near MA
   and VT. Given the high-PW/tropical airmass in place, this heating
   may yield sufficient (albeit weak) MLCAPE for a couple low-topped,
   surface-based showers/storms this afternoon. Any convection that can
   root in the boundary layer may evolve into low-topped supercells,
   aided by strong deep-layer flow/shear associated with Post-Tropical
   Cyclone Debby. 

   Additionally, the aforementioned corridor will be located beneath
   the core of a northward-advancing low-level jet during peak heating
   -- on the eastern periphery of the most substantial surface-pressure
   falls. Here, large, clockwise-curved/sickle-shaped hodographs
   (around 400 m2/s2 0-500m SRH per KENX VWP), will conditionally
   support a couple tornadoes with the more robust surface-based
   convection.

   ..Weinman.. 08/09/2024

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

   ATTN...WFO...GYX...BOX...ALY...BGM...

   LAT...LON   42657438 42987395 43107341 43057259 42917233 42607233
               41887396 41987435 42327450 42657438