FINAL snowfall forecast for tonight

The NWS has issued a snow advisory for areas north of the Mass Pike. Confidence is growing for a 4"+ snowstorm to affect southern NH, northern MA, southern and central VT, and upstate NY.

A disturbance located in southern Ontario will move southeast into NY and then south of the region later tonight. Significant frontogenisis will allow for excellent snow growth conditions, and will bring a 3 hour period of 1" - 2" per hour snowfall rates to the area. The axis of highest QPF right now appears to be from southern VT into northern RI. With another weaker axis to the north. Areas of southern VT and central MA could pick up .75" of water tonight. The WRF model gives parts of S VT up to 1.25"! This is where a few areas may pick up as much as a foot. The NWS in Albany has issued Heavy Snow Warnings for this area. I've moved the 2-4 line west by about 30 miles in CNH. A dry slot between the two heavy QPF axis will keep snowfall under 2 inches for the Plymouth to Concord to Portsmouth area.

The time of the change over will be crucial for many areas in SNE. Cold air is sloped from NW to SE with this storm. Here in Keene, rain will change to snow around 10pm, becoming heavy be 11pm, and ending by around 4am. Despite temperatures just below freezing, snow to water ratios will be high due to the great snow growth. The 2-4 line on the west side has been shifted east because of less suitable snow growth meaning it wont stick for a while. I've started to pinpoint areas of highest snowfall, so have moved the 2-4 line back north in some areas except southward in western MA in consideration of higher elevations. Elevation will play a big role with change over times and snow water ratios. North of the Mass Pike and above 500ft I have high confidence in over 3 inches of snow.

*FINAL*
Snowfall forecast for Keene, NH for 18z Saturday through 12z Sunday (issued at 1145 3/24): 4" - 6" (Locally up to 8" for elevations above 1000ft)

Forecast for selected cities:
Hartford, CT ___ 1" - 2"
Boston, MA ___ 1" - 2" (2" - 4" NW)
Worcester, MA ___ 3" - 6"
Lewiston, ME ___ 1" - 2"
Concord, NH ___ 1" - 2"
Albany, NY ___ 1" - 2"
New York City, NY ___ 0"
Providence, RI ___ 1" - 2" (2" - 4" NW)
Rutland, VT ___ 3" - 6"

Area of highest accumulation:
Bennington and western Windham in southern VT (Locally up to 12").
Cities:
Bennington, VT ___ 7" - 11"