A blast of arctic air is moving in across New England on Friday night, thanks to a large storm offshore that will miss us.
Some rainfall across Cape Cod and the Islands Friday morning was the result of that intense ocean storm passing out to sea to our east. If the storm had come closer, we would have been looking at a blockbuster nor’easter. But the storm will impact New England in one way, and that’s to usher in very cold air on the back side of it.
Temperatures will start plummeting overnight tonight as winds increase and the wind chill temperatures fall below zero. Saturday is going to be a very cold day, one of the coldest feeling days you can get in this part of New England. It’s semantics as to whether or not it’s possible to be a few degrees colder, but the bottom line is that very few people will be spending any time outside on Saturday. Look for wind chill readings below zero all day long and actual temperatures struggling to get to the mid-teens in the afternoon.
As the storm pulls further towards eastern Canada, the winds will relax and after a very cold night Saturday, temperatures will rebound on Sunday. Lighter winds will make it much more tolerable in the afternoon.
We’ve known for many days that there was going to be a storm on Monday. I’ve been writing how the track of this storm would determine precipitation type and now that we are closer to the event it’s looking more and more like a rainstorm rather than snow. We’ve all heard of the term nor’easter for those storms that stay off the coastline. In winter these often bring strong northeasterly winds, heavy snow, or heavy rain. Monday’s storm takes a different track, a warm one.
There will be a quick bit of snow or mixed precipitation Monday morning, changing to rain including inland areas. When a storm moves inland we call it a southeaster because of the southeasterly winds which bring in warm moist air from the Atlantic.
As a kid, I remember a southeaster eroding an entire snow pack in a matter of 24 hours, part of what we would call a January thaw. I’ve seen temperatures go from below zero all the way into the 40s and while we won’t see quite that range Sunday into Monday, it’s going to be close.
As low pressure tracks to our west, marine air will flood the coastal plain and move quite far inland. This will change any snow over to rain, which will come to an end during the late morning along with breezy conditions. It may go into the 40s as far west as the Interstate-495 belt, but it’s definitely going to go above freezing.
Readings above 40 degrees could be common by noon on Monday.
The storm will end up in northern Maine Monday evening, putting an end to the precipitation and allowing cold air to rush back into New England. During the storm, it will become quite windy and it wouldn’t surprise me if we do see some power outages, especially along the coastline as a strong flow comes in off the ocean. Sometimes the strong winds at upper levels of the atmosphere become stuck just above the ground and don’t mix down to the surface. More data in the coming days should give us a better picture of just how bad the wind might be on Monday.
It will clear Tuesday with seasonably cold weather, but more arctic air is possible later next week as the pattern remains quite wintry here in the east.