8:01PM
This is just a quick update on how I think the storm Sunday and Monday will play out…
Some light snow/freezing drizzle Sunday morning over the NH Seacoast down to the eastern MA coast including Boston and its immediate suburbs will be a result of an onshore wind and not directly related to the coming storm.
The precipitation from the storm overspreads southern New England from west to east during the morning and midday, reaching the Boston area by 1PM.
A rain/snow line should be somewhere in southeastern MA and may move north toward Boston for a while, but by late in the day this line will start heading back to the southeast as the colder air wins out. It may take most of the night to make it all the way across the South Coast and Cape Cod so a good portion of the storm there may be in the form of rain. Elsewhere, snow will take over and be dominant.
The wildcard portion of this storm is how much back-lash snow occurs on Monday as the low center gets into the ocean water just to the east of New England and very rapidly intensifies. Right now the greatest chance of moderate to heavy snow lingering through the morning will be across southern NH and northeastern to east central MA, extending down through the South Shore and Cape Cod.
Blizzard conditions are possible along the coast during Monday morning. Blizzard conditions are defined by 3 or more consecutive hours of 1/4 mile or lower visibility caused by falling and/or blowing snow with winds sustained or frequently gusting over 35 MPH.
Ok, so about those snow amounts? This is tricky, but here’s my best guess, and highly depended on both a rain/snow line to the southeast and the amount of back-lash early Monday…
1-3 inches outer Cape Cod & Nantucket at the end, 3-6 inches remainder of the South Coast of New England, 6-10 inches interior southern MA to northern RI northward to about the Mass Pike including Boston, 10-15 inches over central and northern MA into southwestern NH, and 15-18 inches due to extra back-lash snow over northeastern MA and southeastern NH on Monday.
Please understand that these snow amounts are still subject to change and I will update this when needed!
The remainder of this post is from earlier today but has been edited slightly.
DAYS 1-5 (FEBRUARY 11-15)
TONIGHT: Mostly cloudy. Lows 20-30 north to south. Wind light variable becoming NE.
SUNDAY: Cloudy. Spotty very light snow or freezing drizzle near the MA/NH East Coast in the morning. Snow develops west to east midday and afternoon except mix/rain southeastern MA and southern RI. Highs 25-40 north to south. Wind NE 10-20 MPH, higher gusts near the coast.
SUNDAY NIGHT: Overcast. Rain/snow line moves southeastward, crossing Cape Cod lastly overnight. Snow elsewhere. Temperatures 20s north, 30s south, but falling slowly. Wind NE 15-30 MPH, higher gusts especially coast.
MONDAY: Mainly cloudy. Periods of snow favoring eastern areas with heaviest most likely northeastern MA and southeastern NH. See above for accumulations. Temperatures falling to 20s. Wind NE to N 25-35 MPH gusts above 50 MPH interior and above 60 MPH coast.
TUESDAY: Mostly sunny. Lows 5-15. Highs 25-35.
WEDNESDAY: Mostly cloudy. Chance of snow showers. Lows 10-20. Highs 20-30.
DAYS 6-10 (FEBRUARY 16-20)
Snow showers possible to start the period then fair and cold weather dominating, moderating late in the period.
DAYS 11-15 (FEBRUARY 21-25)
Pattern transition underway here but there may be another storm threat during this.