From the National Weather Service:

Major, long duration spring snowstorm will impact the
region Wednesday afternoon through Thursday
evening
* Heavy snow accumulations and snowfall rates are likely,
especially Wednesday night into Thursday morning
+ Sleet may mix in over southern New Hampshire and coast
+ Snow may be wet/sticky especially south of the mountains and
on the coast. This may cause limbs to break and result in power
outages
+ Gusty to damaging winds on the coast, coastal waters, and
southern New Hampshire
+ Minor coastal flooding and splash-over possible
+ The lowest confidence in snowfall amounts remains over
southern New Hampshire and coastal western Maine, where
significant mixing may still reduce totals