fb-pixel;

Last weekend, it was 74 degrees. This weekend, it might snow

Boston Common with a bit of snow in December.
Boston Common with a bit of snow in December.David L. Ryan/Globe Staff/David L Ryan, Globe Staff

It might have been 74 degrees last weekend, but snow is on the way for this coming one.

Wednesday will be the last mild and sunny day for a while. As a matter of fact, I see a much colder and stormier trend on the horizon. On Thursday, there’s going to be a weather system moving to the north of southern New England that will bring several inches of snow to ski country, setting up a nice ski day on Friday.

Readings will approach 50 Wednesday.
Readings will approach 50 Wednesday.NOAA (custom credit)/NOAA

Behind this particular system, the air is going to be quite cold and very dry. This cold will be firmly in place on Friday, when readings will stay mostly in the 20s with teens to the north into Maine and New Hampshire.

Advertisement



Friday night will be quite cold with below-zero temperatures over Maine, New Hampshire, and Vermont, and single digits and teens the further south you travel. Windchills will fall overnight Thursday, and won’t be too far from zero by Friday morning.

Windchill readings will fall near zero by early Friday.
Windchill readings will fall near zero by early Friday.WeatherBell (custom credit)/WeatherBell

This will set up a situation for Saturday afternoon and Saturday night allowing enough cold air for some snow at the start of an upcoming system.

I often talk about the track of low pressure areas and how it depends on the exact track of the storm to determine what type of precipitation we have. If the center of a Maine area of low pressure goes to the west of New England, it will drag warmer air North and often change the precipitation over to rain. If the primary low is off the coast, it will keep the cold air in place, and we often end up with a wintry type of storm.

Low pressure to the west of New England will drag mild air into the area on Saturday night.
Low pressure to the west of New England will drag mild air into the area on Saturday night.Tropical Tidbits (custom credit)/Tropical Tidbits

On Saturday, the main low pressure area will head up west of New England, which will bring milder air from the coastline into the interior. At the start of the storm, there will still be enough cold air present so I do expect some snow. The precipitation may come down quite hard Saturday evening. This is the type of storm where if we stay all snow for an hour or two longer, we will end up with over 3 inches of snow; but if we change quickly, we will only end up with just a coating to an inch.

Advertisement



The red areas have a high probability of 3 inches of snow or more Saturday into Sunday. The probability of over 3 inches of snow Saturday is not high away from the coastline.
The red areas have a high probability of 3 inches of snow or more Saturday into Sunday. The probability of over 3 inches of snow Saturday is not high away from the coastline.WeatherBell (custom credit)/WeatherBell

As we get closer to Saturday, I’ll be able to give a better idea of exactly where the rain-snow line will be and how much snow you can expect. I don’t see a major snow event for southern New England from this particular system as of now, but of course this can change.