GYX
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Overview: Low pressure lifting into the Canadian Maritimes will
drag a cold front across the area Sunday night into Monday
morning. High pressure builds in from the west and crests over
the area Monday night. A progressive area of low pressure will
track near southern New England Tuesday afternoon into Wednesday
morning bringing accumulating snow to much of the area. High
pressure builds in late Wednesday followed by an Arctic cold
front crossing Thursday.
Impacts:
*The Tuesday evening commute likely see impacts from
accumulating snowfall that could linger into Wednesday morning,
particularly across the southern half of the area.
Much of the forecast area south of the mountains will see the
potential for several inches of accumulating snow starting
around mid day Tuesday and lasting into Wednesday morning.
Global models are in general agreement in the synoptic setup
with a low amplitude trough lifting NE across the Mid Atlantic
towards southern New England Tuesday night. However, subtle
differences in the latitude and sharpness of the trough has
resulted in a spread in the track and amplification of the
surface low amongst deterministic guidance. A look at ensembles
shows somewhat better agreement with loose clustering of low
centers tracking near 40N/70W Tuesday evening. The lack of
upstream blocking will lead to the surface low progressing ENE
south of Nova Scotia by early Wednesday morning. This track will
favor mostly snow with DESI showing probabilities of greater
than 3 inches along and south of the foothills around 50-60
percent. The parent trough to this system is currently in the
Gulf of Alaska and will move onshore within better sampling of
RAOBs some time late tonight into Sunday. This will bear
watching over the coming days as the more amplified solutions
will bring the potential for near Warning level snowfall if they
were to verify.
Low pressure quickly exits into the Canadian Maritimes
Wednesday afternoon with high pressure briefly building in from
the southwest. High pressure will be suppressed south Thursday
as an Arctic cold front takes aim at northern New England.