Heavy, Wet Snow Expected Thursday Morning
BOSTON (CBS) - The great thing about storms this late in the winter season is that any one could be the last one.
Of course, you can have storms in March. Heck we even had more than two feet of snow on April 1st back in 1997. But all it takes is a little pattern change and a couple weeks of warmth and our season of snow can be abruptly over.
Looking ahead, there are now many signals that such a pattern change might just be in the works. Many longer range models are now pointing to a mild finish to February.
So, perhaps what I'm about to say might not sting quite as much as it would have say a month or so ago.
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Now, on to our nor'easter coming Thursday.
TIMELINE
This one will start as snow for all of southern New England, but likely hold off for the most part until after Thursday morning's commute.
Several hours of a very heavy, wet snow are likely for our entire area during the late hours of Thursday morning.
Then, a transition will start to occur.
Milder air will flow in from the ocean changing the snow to rain over Cape Cod, the Islands, and eventually much of the east coast of Massachusetts.
This rain/snow line will ultimately be the most challenging part of the forecast. Just how much warm air is drawn in and how far north and west the change line will progress are the burning questions with this storm.
At this point, I think it's a safe bet that the immediate coastline including Boston and back as far as Route 128 will likely change to rain during Thursday afternoon.
I think it's 50-50 whether the rain line makes it as far north and west as Interstate 495.
Beyond that, into Worcester County and parts of southern New Hampshire it looks like all snow and quite a bit of it.
This storm is originating from the Gulf of Mexico, a very juicy place for storms like this in February, so there will be no lack of moisture to work with here.
ACCUMULATION
It is still a bit early for snowfall numbers but I could easily see 6-to-12 inches (or a bit more) in those spots that stay snow for the entire duration of the storm.
Inside of 495, including Boston and places along the coast, I think 3-to-6 inches is a good estimate at this point.
Farther south and east, in extreme southeastern Massachusetts and over Cape Cod and the Islands, most of the snow that falls early on Thursday should be washed away by the heavy rains that follow.
As with any nor'easter, the snow will not be the only issue.
Strong northeast winds will gusts up to 50 miles per hour, perhaps even higher along the coastline. Thankfully, our tides are astronomically on the low side so significant coastal flooding does not appear to be an issue here. However, the seas will be churned up and some minor splashover at the time of high tide is likely. The high tide to watch: Thursday around 10:30 p.m.
At the tail end of the storm during Thursday night, the rain will likely change back over to snow as colder air is drawn back in on northerly winds. We call this the "backlash" of the storm. Think of it as a parting gift or the last gasp of the storm as it is pulling away.
Typically, eastern Massachusetts doesn't get a whole lot of snow with these backlash type of events. Instead, those who got most of the snow typically get the brunt of the backlash. So places like Worcester County and southern New Hampshire may get several more inches before the storm is done with us early Friday morning.
SCHOOL CLOSINGS?
School delays and cancellations may be a tough call for some with the storm not starting until the middle of the morning on Thursday. If the snow does arrive mid-morning on Thursday as we expect, this could be a situation where schools are forced to let out early in the middle of some very heavy snow.
While the storm will likely be over by Friday morning, some residual delays are likely with a very sloppy cleanup underway.
This is one of those storms where timing and temperatures will be critical.
A change of a degree or two for an hour or two will make a huge difference.
I would advise staying tuned to updated forecasts over the next 48 hours. This storm will make a mess of the entire East Coast with rain, ice and snow from Atlanta to Boston, so expect numerous and lengthy travel delays.
But remember these *COULD BE* some of the last flakes we see this winter, so try to take it all in and enjoy it while it lasts!
This is after all why we live in New England, right?
Follow Terry on Twitter @TerryWBZ
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