From NWS bulletin
.KEY MESSAGE 4...
There continues to be a lot of uncertainty with the track of low
pressure developing along the east coast Sunday and passing to the
south and east Sunday night into Monday. Recent trends in the both
the dynamical and AI models are clearly trending toward a more
southward suppression of the storm track. The
GFS in particular is
the most suppressed, keeping the area dry. Even the Canadian which
is still fairly wet, has shown a trend in the highest
QPF axis to
shift south. The latest long term NBM (13Z) has come up with chances
of snow, but based on trends in the 12Z guidance wanted to keep
chance
PoPs no higher than 50 percent. NBM probabilities for snow
amounts of 6 inches or more Sunday into Monday rage from 40 percent
inland, to around 60 percent across Long Island and southern
portions of the NYC
metro. The main reason for the differences in
the guidance are
likely due to the amount of interaction between the
southern and northern branches of the polar
jet. The 12Z guidance is
showing less phasing with the
GFS leaving much of the energy behind
across northern Mexico.
Bottom line, we are not out of the woods yet on an accumulating
snowfall event for the region on Sunday, but the next 24-48h will be
critical to see if models find some continuity and lock on better to
a solution.