THUNDER BAY — Residents of Thunder Bay can expect to be greeted with mid-winter-like temperatures when spring makes its debut this week.
The vernal equinox happens at 11:06 pm Tuesday, and Wednesday marks the first full day of spring, but Environment Canada is predicting overnight temperatures well below normal from Tuesday night through Thursday night.
"It's a major shift in the weather pattern for the coming week right across Northwestern Ontario and north of Superior," said meteorologist Geoff Coulson.
At this time of year, the thermometer should bottom out at about -10 C, but the current forecast calls for lows of -17 to -20.
Daytime highs this week will average a few degrees below normal.
"We've had air masses coming in from the west or the southwest, tending to give us overall mild conditions throughout the area" recently, Coulson said. "Now we're really drawing down the cold arctic air from the northwest. And this arctic air is likely gonna be with us through the remainder of the week."
A return toward normal temperatures is expected on the weekend, but Coulson said the reprieve may only be a short one.
"Some of the forecast models are indicating a major system that could move south of Thunder bay and could pull down more cold air for next week as well. But the exact track of that system is still uncertain."
Overnight Monday, the city is expected to receive two to four centimetres of snow, followed by a spell of sunshine from Wednesday through Saturday due to the arrival of a large area of high pressure.
