By Monday night snow and/or rain should be covering the entire area
and continue through Tuesday as the low pressure tracks across Lake
Ontario during the day on Tuesday. As of now, it looks like it
should be cold enough from the onset of the precipitation through
the middle of Tuesday morning to stay as mostly snow before mixing
with and changing to rain. With temperatures staying cooler, some
areas over the higher terrain and across the North Country may stay
as all snow. Temperatures will be dependent on track of the system
and strength of warm air advection with that track. A track farther
north or south will affect the temperature profiles, and therefore
the precip types. As the low and cold front pass through the area,
any rain that is falling will change back to snow Tuesday evening.
Lake enhanced/effect will
follow in the wake of the main area of precipitation as cold air
advection occurs behind the passing cold front and area of low
pressure. Light lake effect snow will continue through Wednesday as
the area will be under the influence of a large trough associated
with the low pressure from Tuesday. With this trough still over the
area, cold air advection will continue and synoptic moisture will be
in place through Wednesday to support lake effect. Model spread is
present for 850 temperatures on Wednesday with the GFS not cooling
to -10C or lower and the ECMWF cooling to around -14C, if the GFS
850Ts are realized, then any lake effect for Wednesday should be
light as equilibrium heights should be lower than with colder 850Ts