Mesoscale Discussion 0042
   NWS Storm Prediction Center Norman OK
   0713 PM CST Mon Jan 20 2025

   Areas affected...portions of far western New York

   Concerning...Heavy snow 

   Valid 210113Z - 210415Z

   SUMMARY...Heavy snow should develop through tonight with an
   approaching lake-effect snow band. 2-3 inch/hour snowfall rates are
   likely, at least on an intermittent basis.

   DISCUSSION...While heavy snow has recently been reported by the KART
   ASOS, the ongoing snow-band should shift several miles southward
   over the next couple of hours, as indicated by KTYX regional radar
   data. The CWQP surface observation along the Ontario shoreline
   showed an abrupt wind-shift and brief increase in speed as the
   snow-band shifted to the south of this location, indicating
   potential appreciable low-level convergence. The strong convergence
   associated with the approaching snow-band, amid 8+ C/km 0-3 km lapse
   rates, suggest that the snowfall is likely associated with
   low-topped convection. The low-topped convection will benefit from a
   long fetch of Lake Ontario moisture as low-level flow parallels the
   lake axis this evening. Heavy lake-effect snow should begin soon,
   and given convective banding with 90 percent RH in the dendritic
   growth zone, production efficiency may be high enough to support at
   least 2 inch/hr snowfall rates, perhaps reaching 3 inches/hr at
   times.

   ..Squitieri.. 01/21/2025

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

   ATTN...WFO...BUF...

   LAT...LON   43867632 43927582 43917548 43787548 43697575 43687615
               43757627 43867632