UPDATE, 4:15 p.m.: According to the latest data, the storm appears to be shifting to the south and will not materialize as we thought the past couple of days. I will have some updates in the next few hours, but key points are a later start Tuesday, no intense hours of snow bands, less accumulation. The morning commute may actually be dry.
Every six hours meteorologists get a set of new data, and last night’s data indicated a trend of keeping this snowstorm farther south. This doesn’t mean we would miss our predicted nor’easter in New England, but it may mean that the heaviest snow ends up shifting from the way it looked 24 hours ago on forecast maps.
One of the more reliable weather forecasting models — the European model — continues to show that this storm is going to miss us, shifting about 200 miles south. If this guidance ends up being correct, then the prediction for heavy snow and wind would not materialize. We would see little to no snow across the northern towns of Massachusetts and perhaps 1 to 4 inches closer to Boston, with 4 to 7 inches farther south. This possibility has to be considered even at this late date, with less than 24 hours until the storm is supposed to begin.
The European model ensemble forecast below has virtually no chance of heavy snow — 6 inches or more — for the most populous areas of Southern New England. There’s another set of data we will get this evening, so it’s important to stay tuned to the latest forecast, and if you’re a superintendent of schools and can hold off making the call, I would do so.
The GFS model shows the heaviest amount of total precipitation is still forecast to be south of the Mass. Pike. The numbers you observe are either rain or the total water equivalent of the snow itself. This is a lot of precipitation, and for those areas that receive mostly snow and the heaviest amount of water equivalent, there’s going to be quite a bit of it.
Expected snowfall accumulation
I have made some changes to my snow maps. Once further information is available later today, we could see more of a shift south of the heaviest snow or it could end up staying as is.
Right now, we’re looking at:
• 8 to 14 inches — Boston area and south of the Mass. Pike, and most of Rhode Island and Connecticut.
• 4 to 8 inches — North of the Mass. Pike and Western Massachusetts.
• 2 to 8 inches — Along the coast and on the Cape.
• 2 to 4 inches — Southern Maine
• Coating to 2 inches — New Hampshire and Vermont.
A winter storm warning has been issued for central, eastern, northeastern, and western Massachusetts and northern Rhode Island starting at 1 a.m. Tuesday and lasting until 1 a.m. Wednesday.
Timing of the storm
The precipitation will arrive Tuesday morning. If you need to get into work, you’ll be able to travel pretty easily for the first part of the commute, but once we get past roughly 8 a.m., conditions will deteriorate.
I think the heaviest part of the storm comes in during the mid to late morning and in through the afternoon. At times where it is snowing heaviest, it could come down at a rate of 1 to 3 inches per hour, making travel very difficult because visibility will be reduced.
Boston Mayor Wu on Monday declared a snow emergency in the city beginning at 10 p.m. Monday and canceled classes for Boston Public Schools.
The wind will be noticeable, but it’s not going to be excessive. Across Cape Cod and the Islands there is a high wind warning as winds will gust over 50 mph in some locations, creating scattered power outages, especially as the rain transitions over to a heavy wet snow.
Some parts of the Outer Cape could experience blizzard conditions Tuesday afternoon for awhile, meaning quarter-mile or less visibility and winds gusting frequently over 35 miles per hour.
There’s likely to be minor to borderline moderate coastal flooding at the time of high tide, certainly nothing extensive. A coastal flood warning has been issued for the shore of Massachusetts and the Cape.
The good news is that the entire system is moving very quickly. Just after dark on Tuesday it will all be over and folks will have an opportunity to clean up for the morning commute on Wednesday. With no snow on the ground and no snow banks, there’s plenty of room to put everything even if you receive over a foot.
Sunshine returns Wednesday with typically cold air for February and highs in the 30s.