From the National Weather Service:
Significant Winter Weather event Late Wednesday night into Thursday evening with snow/wind
A cold front will pass offshore and south of New England. Low pressure will form along the front near the mid Atlantic and rapidly intensify passing south of Cape Cod on Thursday
Forecast and Discussion:
A cold front will usher in arctic air at all levels of the atmosphere on Wednesday. Guidance is in good agreement on surface low pressure developing along the front off the mid Atlantic coast. Latest guidance showing a track over or just outside the 40N 70W benchmark position for New England storms. The system will rapidly intensify as it tracks NE. Conditions will be excellent for snow growth potential and a widespread 8-12” of snow are likely for much of southern New England. A winter storm watch has been issued by NWS for all of the forecast area except Nantucket which could see a mix with rain for a time holding down accumulations. Snowfall rates of 1-2” per hour are possible at the height of the storm on Thursday. The Thursday morning commute could be extremely hazardous for travel. Snow consistency will be wetter than some of the previous events, especially along the south coast, Cape/Islands where it will stick to power lines and trees. A more dryer snow will be in northern sections, but also will dry out as the system pulls away and snow ratios increase with a dryer moisture column. Some precipitation could linger into the evening in eastern MA possibly affecting the evening commute. This remains uncertain at this time. A good pressure gradient will result in winds near 55+ mph, especially over the cape and Islands. Isolated gusts over 60mph are possible in these areas. Winds to 45-50mph are possible in other coastal areas of Eastern MA. Only minor splash over is anticipated at this time and moderate coastal flooding is not expected. If the track is a bit further north, more mix will reduce amounts along the south coast and increase the threat to Boston and Metro-West. If the track is a bit farther south outside of benchmark, the south coast Cape /Islands will get the highest accumulations. The system is progressive and should be pulling away late Thursday.
More later as new data comes in…..