Low temperature records set in Maritimes, chances of snow on Thursday

CTV Atlantic meteorologist Kalin Mitchell goes over the factors contributing to snow showers in the forecast for parts of the Maritimes.

Temperatures in the Maritimes are well below average for late April.

Records set

Low temperature records this morning were set in the following communities:

• Doaktown, N.B. at -7.7 C
• Grand Manan, N.B. at -5.0 C
• St. Stephen, N.B. at -6.9 C
• Charlottetown at -7.6 C

There have been two main contributing factors for this cold. The first, a northerly flow of air out of Labrador and Quebec on Monday and Tuesday, ushering in chilly air to the region.

The second is a pool of cold air located in a dip in the mid-to-high levels of the atmosphere. About 1.5 kilometres above ground, the air temperature is seven to 10 degrees colder than typical.

The temperature there hovers close to –10 C.

Thursday snow showers

Since the air temperature aloft determines the type of precipitation that develops, there has been some late April snow mixed in with the scattered showers through the start of the week.

In most cases, the snow hasn’t collected but a few communities in the Maritimes have reported a skiff on the ground in the early morning hours.

The cold air above remains in place as a trough of low pressure moves into the Maritimes for Thursday.

It is very likely there will be some snow showers along with the rain showers from that system.

The snow showers will be most likely Thursday morning in western areas of both New Brunswick and Nova Scotia.

Some forecast guidance indicates snow amounts of up to two to five cm could fall.

Given how late it is in April and that the ground is no longer frozen near the surface for most of the region, very little of that snow is likely to collect.

Residents might find more add up on objects like cold car roofs and tree branches, but less on paved surfaces that are starting to retain more warmth from the spring sun.

Elevation can make a big difference this time of the year as well. More snow is likely to collect at higher elevations than lower ones, especially low elevations near the coastline.

Pattern change

The anomalously cold air above is forecast to alleviate early next week. That will help to return temperatures in the Maritimes towards seasonable or a bit above as April closes out and turns to early May.

The Maritimes isn’t alone with the late April snow. A significant mix of snow and freezing rain has been falling in Newfoundland and Labrador going back to Tuesday.

Snow and winter storm warnings have been issued in northern Saskatchewan and northern Manitoba. A heavy spring snow starting Wednesday night and continuing through Thursday may bring that part of the country snow amounts of 20 to 50 cm.