As I heard someone say earlier, we’re going to hit the Weekend Trifecta in regards to winter storms. We are not hitting any trifecta with computer models, as the 3 main ones are in great disagreement only 48 hours out from the storm. So, as I did previously, I’m sticking closer to the one most consistent and proven most accurate in recent events (though it has made some adjustments on the latest run which I am taking into account).
Before we get to the storm, we first have what’s left of a windy/cold Thursday to finish off and the winds will finally slacken as the night goes on and we’ll end up with a mostly clear and cold night, leading into a pleasant, bright, and chilly Friday (sometimes referred to as a “weather breeder day” or more commonly known as “the calm before the storm”). Whatever nature is breeding will be coming in lazily on Saturday in the form of a cloudy sky at first. The process taking place will be a primary storm moving northeastward into the Great Lakes and a secondary storm being born on the Mid Atlantic Coast. The track of this secondary storm will be the key in determining how much precipitation falls, the positioning and movement of a rain/snow line, and ultimately the end result in terms of snowfall amounts. Whatever happens, I do not expect a whole lot of snow to be on the ground before midnight Saturday night. The bulk of the precipitation, in whatever form, will take place Sunday morning (in the 12 hours between midnight and noon), with it all winding down during Sunday afternoon and evening. With decent confidence I will say that heaviest snow amounts will take place north of the Mass Pike. I think spotty precipitation will take place any time from later Saturday afternoon through Saturday evening before growing steadier. Where rain is mostly is along and south of the Mass Pike and especially close to the coastal areas. As steadier precipitation gets underway later at night, this rain/snow line will be tough to determine and will become a now-casting situation, but what I expect is that it will hang on right along the South Shore of MA and across Cape Cod and the Islands and possibly coastal RI as well. Some mixing is possible in an area between this and an all snow area mainly along and north of Route 2. Eventually the rain/snow line will collapse to the southeast and areas that are raining will turn to snow. The amount of snow in these areas will depend on the timing of the change to snow. Taking all this into account and sticking to my general rule of not putting out snow #’s until about 48 hours prior to the start of an event, I will issue a best guess on final accumulations here…and keep in mind this will not fall all at once, it is a total amount of snow expected from the onset of spotty precipitation Saturday to the end of snow on Sunday night. Amounts may be nothing like what fell in the blizzard 2 weeks prior, but impact could be greater since it will be a heavier, wetter snow, tougher to move and more conducive to producing damage to trees and power lines. Accumulations expected from the Saturday night through Sunday evening event: 1-3 inches Cape Cod and the islands and right on the coastline of RI and Plymouth County MA, 3-6 inches elsewhere south of the Mass Pike, 6-9 inches north of the Mass Pike including southern NH, with isolated 10+ inches mainly in higher elevations.
A break comes Monday as the weekend storm will be gone and the atmosphere will be in the process of thinking about what to do with us for the end of February and to welcome March. I hear that it may be thinking about hiring a lion for the party… More later!
Detailed forecast for southeastern New England…
TONIGHT: Partly cloudy early then clear. Lows 17-26, coldest inland valleys. Wind NW to N diminishing to around 10 MPH.
FRIDAY: Mostly sunny. Highs 33-40, coolest in the hills northwest of Boston. Wind N 5-15 MPH.
FRIDAY NIGHT: Partly cloudy early. Mostly cloudy late. Lows 20-26. Wind light E.
SATURDAY: Mostly cloudy morning. Cloudy afternoon with spotty light rain or snow. Highs 35-42, mildest Cape Cod area. Wind SE 5-15 MPH shifting to NE late.
SATURDAY NIGHT: Overcast. Precipitation becoming steadier, light to moderate early, moderate to heavy overnight, mostly rain/mix south of the Mass Pike, mix/snow to the north. Rain/snow line may move southeastward rapidly toward dawn. Temperatures falling slowly, mainly middle to lower 30s, some upper 20s well north and west of Boston. Wind E to NE 10-20 MPH with gusts over 30 MPH especially along the coast. Some coastal flooding possible east-facing shores around the 10PM high tide.
SUNDAY: Overcast. Snow/mix becoming all snow, possibly heavy at times morning, tapering off in the afternoon and evening (see expected snow amounts above). Temperatures steady mainly upper 20s to lower 30s northwest to southeast. Wind NE to N 10-20 MPH gusting over 30 MPH especially along the coast. Some coastal flooding possible at north-facing shores late morning high tide.
MONDAY: Mostly sunny. Low 20. High 40.
TUESDAY: Increasing clouds. Snow/mix/rain at night. Low 25. High 38.
WEDNESDAY: Cloudy. Rain/mix likely. Low 32. High 36.
THURSDAY: Cloudy. Mix/snow likely. Low 30. High 34.