Workweek Outlook: Massive storm ushers in heavy rain and then winter

The warmish pattern that we have enjoyed in the Sault area for the last couple weeks is about to come to a sudden halt.  A storm originating in the upper American Plains will move into the Superior region Monday and strengthen.  It will generate such a strong wind field that it will pull colder air from the Arctic into the region on Tuesday.  This massive area of cold air will then settle in across Ontario and could last well into the middle of this month.

When this impressive storm system moves into the region Monday it will bring heavy rain.  There is even the risk of isolated thunder and lightning. 40-60mm of rain could fall Monday and into Tuesday morning with higher amounts possible east towards the North Shore. Gusty southerly winds will blow Monday and increase in speed during the evening, and overnight as the centre of the storm nears. Temperatures will climb all Monday and max out near +10C near midnight.

 Strong southwesterly winds with gusts over 60km/h arrive Tuesday and rapidly push temperatures down through the day.  The Sault region will fall below freezing by the late afternoon. Light snow is possible through the day. 

Wednesday will see the light snow continue with the best chance for snowsqualls north of the city along Eastern Superior. 4-6cm of snow is possible in the city with higher amounts to the north as temperatures remaining below freezing.

This cold snap will last well into the end of this week and the upcoming weekend with daytime highs several degrees below freezing and overnight lows near -10C.