Weak storm system which brought the snow, sleet, freezing rain and rain to southern Ontario earlier today continues to track quickly toward the east. Snow will taper off across southern Quebec this evening. Freezing drizzle still could be an issue through this evening for areas north of Toronto.
A second storm system will move out of the Rockies into the Plains overnight tonight and will spread light to moderate snow up into northwestern Ontario late tonight into Tuesday. The map below shows the expected accumulations.
The third and final storm will track up into the Great Lakes by Wednesday morning. This storm will spread even milder air up into Ontario and Quebec Tuesday night into Wednesday along with a period of steadier rain and even a thunderstorm, especially over southern Ontario. Cold, low-level air may hang through Wednesday morning just north of the St. Lawrence River Valley in Quebec for an extended period of ice before it too changes to plain rain.
Once this storm moves by, the cold air will quickly wrap back in from west to east across Ontario and then into Quebec Wednesday evening.
The air should get cold enough for a return of lake-effect snow in the usual snow belts off Lake Huron starting in the early morning hours of Thursday and continuing into Thursday night.
Cold pattern persists into the weekend with possible snow for Ontario Saturday due to an Alberta Clipper.
A surge of Arctic air will pour southward through Alberta late tonight and spread into Saskatchewan by Tuesday. Along and right behind the Arctic front, there will be a period of snow with gusty winds and poor visibility. Most areas will see 2-8 cm, especially over the southwestern half of Alberta, including Calgary. Temperatures will just fall during the day Tuesday in Calgary and Regina.
Wednesday night will be bitterly cold across the southern Prairies with many areas reaching or even getting lower than -35 C.
Once again, the latest Arctic air mass will miss British Columbia as the Rocky Mountains act as a barrier, preventing the cold from spreading southwestward.
Pattern of extremes into next week and a look at August.
One of the worst wildfire seasons in recent time across the Northwest Territories is causing a massive plume of smoke....
Pattern does not favor any sustained heat waves the rest of this month from the eastern Prairies to Quebec.
A look back at the wind and rain reports from Arthur....
My second Friday update on Arthur....
It looks like Arthur will be making a direct hit on Nova Scotia late Friday night into Saturday with heavy rainfall back into New Brunswick.