Late Afternoon update
When you see snowfall rates of 2-3 inches per hour you really have to appreciate the atmosphere. When predicting snowfall totals, these heavier bands make it extremely difficult to hit the upper totals. As of 3:00PM the back edge of the snow was pushing northeast and should reach Boston around 6PM give or take a bit of time. It looks to me like the snow tapers off quite quickly from accumulating snow to no snow. The good news is that it will end early enough this evening to give you time to clean-up and it’s not going to get cold behind the storm. Overall, most areas east of Route 495 will end up at the high end of the predicted range from yesterday or an inch or so over.
The blog from earlier today is below.
There are still a few questions about the snow today, but you can expect snow to begin later this morning and become heavy for a few hours this afternoon. The highest totals will be north and west of Boston with less snow the further south you are today. The wide map shows how much snow the area will see and the close-up map gives an idea of how much snow metro Boston will receive.
The reason for the snow is a weather system moving eastward this morning from the Great Lakes area, but then redeveloping in to a new storm just off our south coast. As the storm then moves northward into the Gulf of Maine an area of snow and rain will occur.
This most notable piece of today’s weather event, besides it being the third time in a week we’ve had snow, is the intensity it will snow for a few hours during the afternoon through until about 4 to 5 PM. I’ll update the progress of the heavy snow here and also on Twitter as usual.
Snow amounts are not going to be large. Boston could see as little as an inch or as much as 3 inches. I don’t expect the city itself to go higher than that because the system is moving so fast. While it’s cold this morning and many places had temperatures in the single numbers, milder air will change the snow to rain south of Boston. For Cape Cod and the Island the rain/snow mixture keeps snow totals very low. That mix could even make it to Boston just before the precipitation ends.
Updates all day @growingwisdom on Twitter.
I mentioned there are still a few questions with this storm. When you have a storm redevelop off the coast, the precise position and timing of the redevelopment play a big role in the snow to the north of the new storm. The two maps below show how the secondary storm will take shape later today. In the second map, the storm is just east of Portsmouth with the heaviest snow in the blue area to the west of the storm. If the storm develops just a bit slower than anticipated, it will spare the northern sections of Massachusetts the heaviest snow exceeding 6 inches.
The reason for the winter storm warning today north and west of Boston is based on the exact strengthening of this low pressure area. You might ask what if the storm gets stronger earlier. While less likely, if the storm did get stronger earlier, it will bring more snow to Boston, but I don’t see this happening because the atmosphere is moving very quickly and there is nothing to block the storm from chugging along.
The whole thing ends by 7PM and perhaps even earlier, but the damage to the evening commute will have already happened. For the ride home, the roads south of Boston should have slush or just wet pavement while those of you taking Routes 93 and 95 northbound will see more snow on the roads. The Massachusetts Turnpike west will actually improve past Route 495 and the snow will have ended their before 4PM giving road crews a chance to clean-up.
Tomorrow will be an unsettled day with a few periods of snow or rain showers, but also some mid-afternoon sunshine mixed in. Temperatures will make a run at 40F, so melting will occur. Thursday is my pick of the week as high temperatures get into the mid-40s with sunshine. Rain, not snow is the forecast for Friday and that is going to be our mildest day of the mini-thaw. It’s not cold this weekend, but the cold does return next week. Temperatures will likely stay well below freezing for several days next week.