The GYX long term lays it out well
NG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
500 MB pattern continues with split flow and very blocky, weak
flow through the end of the week at least. Some changes possible
this weekend as possible strong E Pacific ridging develops,
setting up a stronger +PNA pattern, followed by a developing
block over the Atlantic early next week and a possible -NAO.
Following the Euro this would portend more winter-like
conditions. However, the previous models run, showed nothing of
this sort, so confidence is low.
Main event in the extended will be the coastal low developing to
our S late Thu and quickly tracking E across the Gulf of ME.
500 MB closed low over the N Plains on Thur moves quickly to the
E Thu night and Fri and does manage to some brief phasing and
become weakly negatively tilted, which should produce a burst of
decent dynamic and mid-level thermal forcing Thu night, with a
decent burst of precip /mainly snow/ Thu night. Highest QPF, for
now, is over southern NH, but it may start as rain here Thu
afternoon before changing to snow. Also, warm antecedent temps,
may limit accums early on as well. However, snowfall rates could
be intense for a few hours overnight, and this may help
overcome some of the warm ground melting. Several inches look
possible, with the bulk of the snow falling Thu night. Lows Thu
night will range from around 20 in the N to around 30 in the S.
On Friday, the sfc low will quickly move into Nova Scotia, but
weaken sfc low associated with upper level low will move across
proving some light snow, especially in the morning, with Highs
generally in the up[per 20s to low to mid 30s in the S.
SHSN possible in the mtns Fri night, but cold aid air behind
this system is limited and will last for a day as Sat highs push
back into the upper 20s to mid 30s, but Sunday they will be in
the 30s to around 40 in southern NH. There is a chance for some
SN Sunday night into Monday, but latest Euro and GFS are very
different in that period, so Chc POPs are quite reasonable attm.