A moderate snowstorm blew in an out of southern Maine last evening and by the time it was done several areas had received 5-10 inches of fresh snow. This was more than was expected, especially south of Augusta. These reports will be updated later today.


The atmosphere was charged up with a lot of energy last night and this helped produced thundersnow. Thundersnow isn’t unique, but certainly more common in snowstorms closer to spring when the atmosphere is usually a bit warmer.

You might wonder how is can thunder and have snow at the same time. In the summer, many thunderstorms are caused by warm air being lifted off the ground and rising up to 40,000 feet or more. In the winter the lift is occurring within the clouds in a relatively shallow layer. Since winter precipitation clouds tend to be flat, thundersnow happens when these flat clouds develop “turrets” or bumps in them.

Last night there was a strong piece of energy moving through the atmosphere which created the necessary lift, or catalyst to give rise to these turrets and bring about the thundersnow. The image below from WeatherUnderground gives a nice visual of this phenomenon. Even if you didn’t get thundersnow in your area, the intense snowfall rates were present.

Thundersnow Credit:Weather Underground

Thundersnow Credit:Weather Underground

Just like in the summer when heavy rain can fall in a very short period of time during a thunderstorm, in winter a large amount of snow can fall in an hour. Last evening, in the Sebago Lakes area 6 inches of snow fell in an hour!

thundersnowdsf 1

The radar image below shows where the heaviest snow was occurring last evening. Notice the shape of the band is very similar to a line of thunderstorms in the summer.

Radar southern Maine 10 p.m 1-12-16

Radar southern Maine 10 p.m 1-12-16

Wind and cold are the predominant players in our weather today with particularly blustery conditions this afternoon. The next storm arrives Saturday with snow and even a possible change to rain.

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