With the exception of losing a really warm day (which is always nice) GYX is optimistic re the return of winter. Ya wonder how much that Thursday low will bring. But either way, there should be a frozen coating for snow to begin to lie on at some point in the not too distant future post Friday.
For the temperature and resultant precipitation forecast,
primarily colder guidance, especially the high res NAM was
used. There is still likely some room to bring temperatures down
further in future forecast packages for Tuesday as all of the
guidance trends in the cool direction. Outside of the mountain
valleys it`s unlikely that any areas would stay below freezing
for more than a few hours once the precip begins, but temps are
likely to sit between 33-36 degrees much of the day afterwards,
with the highs for the day likely occuring in the late afternoon
and evening hours.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Based on a multi model consensus it appears like winter returns
to much of the forecast area as cold air sags southward out of
Canada and allows for overrunning precipitation from time to
time Tuesday night into Friday.
While temperatures warm appreciable aloft Tuesday night (up to
+11c at 850MB in the southern zones), weak SFC low pressure
looks to form in the Gulf of Maine as well which should keep any
sort of warm front from zooming northward through our forecast
area. While highs around 60 are still possible for southern NH
on Wednesday, the rest of the region should see highs falling
into the 40s and 30s as cold air bleeds in from the north as per
many of the 00z deterministic models. Have blended several of
these models in with the NBM which I believe is still too warm
for Wednesday. With overrunning precipitation expected on
Wednesday and cold air undercutting the warm air aloft, we
should see some frozen or freezing precipitation falling in the
mountains by the end of the day with some freezing rain
accretion likely.
The forcing for ascent wanes Wednesday night but warm and moist
SW flow above a cooling boundary layer should still offer light
precipitation, a mix of snow and freezing rain as far south as
portions of central NH and southernmost ME by 12z Thursday.
Therefore a slippery morning commute Thursday is quite possible.
Light frozen or freezing precipitation continues Thursday as
another low pressure system develops just off the coast with
cold air now firmly entrenched at the SFC most areas of the
forecast area.