Here’s why they expanded. We’ll see if it works or not.
expanded the Winter Weather Advisory to include; western zones
of Franklin and Hampshire Counties, Worcester County, Tolland and
Windham Counties, most of Rhode Island, and all of southeast
Massachusetts. Here we feel there is the best potential for 2-4"
with the higher of the totals on the western facing hills, due to
upsloping from the southwest flow.
Forecast Details: Quiet through the rest of the daylight hours, then
a robust 850mb shortwave races through southern New England this
evening through early tomorrow morning. This feature has near normal
moisture to work with, PWATs of 0.3" to 0.4" doesn`t sound overly
too impressive, but is enough to work with. Looking through BUFKIT
forecast soundings, there is good saturation and OMEGA/lift in the
dendritic growth zone (DGZ), with light to moderate snow for several
hours 2am to 6am. HREF supportive of this idea, with probabilities
between 30% and 60% for snowfall rates 1+" an hour during this time
across Connecticut, Rhode Island, and southeast Massachusetts. As
mentioned above, those traveling late tonight or tomorrow morning
will want to plan accordingly as slick travel is expected. There is
a level of uncertainty around how far north the warm air reaches,
for the time being confidence for the northern extent is Nantucket.
It is there the best chance for rain to mix with the snow.
Elsewhere, remains cold enough to stay snow. Additionally, southwest
flow enhances snow potential due to orographic lift/upslope along
western facing hills of northeastern Connecticut, central
Massachusetts... even western hills of Rhode Island benefit from an
upslope component. Finally, the shortwave moves off shore early
Thursday morning, followed with an Arctic front midmorning, with
additional snow showers or possibly snow squalls.