The heavy bands of snow have left the area, and all blizzard and winter storm warnings have expired. A winter weather advisory is in place overnight for periods of light snow, which could amount to a coating to an inch or two. Temperatures will continue to remain in the teens to lower 20s. A few periods of snow showers could occur again Wednesday as colder air rushes into the region to close out the work week.
Late afternoon update
Snow is shrinking in area coverage and has developed into a very banded pattern, which means it's snowing quite hard in some places while the intensity is lighter in others. This will show up in the final snow total, and it's impossible to know these bands are going to set up exactly in the spot they do, although the GEM (Canadian model) had a good idea of the pattern:
Here's that look at the Canadian model. Notice the pattern of the banding is similar to the actual radar. However, the placement isn't quite correct:
The latest map shows many half-mile visibility reports, with lower visibility over the Cape and Nantucket. If you can see half a mile, then snow is accumulating about an inch every two hours. When visibility drops to a quarter-mile, as it has along the south coast, snow piles up at a minimum of an inch per hour. The worst of the storm will remain south of Boston, although there may be a one- to three-hour period when Boston sees heavy snow this afternoon.
If the wind early this morning across much of the area doesnít help you understand the strength of the storm, perhaps the satellite loop below will. This is a very intense Atlantic storm, with warnings for wind, snow, and coastal flooding. Itís a good thing this storm is staying hundreds of miles out to sea, because it would have left an indelible mark on the coastline and much of the area if it were moving north, not east.
Like a hurricane, this storm has bands of precipitation across its western flank, and these bands contain very heavy precipitation. Within these bands, snowfall rates of 1 to 3 inches per hour can occur, but if the bands stay out of your area, then you're left with much lighter snow. The banding structure of this storm will make final accumulations vary widely.
There is a blizzard warning posted for the south shore, Cape and the islands. This is due to the strong winds and falling snow which limit visibility.
There have been so many maps out there with snow totals, so I decided to break down the accumulation into blocks. There will be some additional snowfall later this afternoon and overnight, but not much. The snowfall maps from this morning are broken into two pieces: what falls through 3 p.m., then from 3 p.m. through late evening. I still feel comfortable with these totals:
There is a lull in the snow for Tuesday during the daylight hours, with clouds, a few breaks, and perhaps some snow showers.
On Wednesday, a weaker system passes to the south of the area and could bring some light snow, mainly south of the Turnpike. An arctic front moves in Thursday, ushering in the coldest air of the entire season.
Temperatures over the weekend could reach zero, even in Boston. Some moderation in the cold takes place next week. The two-week period which began with last Friday's snowstorm is likely going to end up as the coldest and snowiest part of the entire winter season.
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