November is traditionally the month when southern New England (and northern) sees its first flakes and first measurable snowfall. There have been years when we’ve had to wait much longer before the first measurable snowfall occurs, and a few years with October snow. When I use the term measurable, that would be a tenth of an inch of snow, enough to turn the ground white, even temporarily.
Occasionally, the first flakes are also the first snowstorm; in other years, we might get a dusting of snow and then have to wait much longer before we’re shoveling. On average, the first measurable snow occurs in the third week of November west of the coastline and in the final few days of November right at the coastline, including Boston. Some years we all see the first snow on the same date, but other years the coast gets rain while inland areas have snow for the first few storms.
Here’s a fun thing to think about. Depending on when the last snow occurred the previous winter and when the first snow occurs in the new one, there can be very long gaps or very short gaps between snow. In the winter of 1936-1937, there was so little snow, there was over a year between one inch or more snow events.
Snow seasons have highly variable numbers. The longest season on record is 1977, when measurable snow began in mid-November and continued until the second week of May.
The amount of snow we see each year is also highly variable. There’s over 100 inches between the most amount of snow in a season and the least. Although we have dry and wet years, snowfall is incredibly variable. The winter of 2011-2012 produced very low snow, while just a few years later we had over 100 inches.
This year, November is about to turn quite cold. Temperatures will be under the long-term averages for the next couple of weeks. It stands to reason that with this cold air we have the chance to see our first snow earlier than usual. From my standpoint, the first snow is also one of the more difficult things to predict. The ground is often still warm, and sometimes you can have a few hours of snow, but it just doesn’t accumulate enough to be measurable.
There are multiple shots of colder than average conditions in the forecast through mid-month.
Cold air arrives here on Friday and will continue into the early part of the weekend before we see a moderating trend. It looks like there’s another chance for cold air during the middle of next week, and one of our computer models actually does have some measurable snow predicted.
These long-range projections are not highly accurate, but it does give us an idea that the atmosphere will be cold enough to support snow. The question is whether or not the moisture is ultimately there. The bottom line is that November snow is typical, and it’s likely going to be back in the forecast over the next couple of weeks.