Before I get into tomorrow’s storm, just a note that December snow totals where above normal in many regions across Southern Ontario.  Specifically Ottawa finished December with 99.8 cm which is well above normal and one of our snowiest Decembers in many years, since at least 2007.  In my winter forecast back in November I noted that past analog years also had snowy Decembers.

So on to the storm tomorrow; this is a similar Colorado low that went through on Boxing Day.  This one is also cutting west across the lakes due to the Southwest Ridge in place.  This one is bringing freezing rain, rain and wet snow.

It will mostly be rain in Southwest Ontario and around the GTA.  North and east of that area will start as ice pellets and freezing rain before changing to rain.  Ottawa and the region will start as snow and ice pellets and changing to freezing rain before morning.  Ottawa and especially up the valley towards Pembroke could see significant freezing rain throughout Tuesday before it changes to rain in the afternoon or early evening.

Some of the recent models runs also show there is also a possibility it changes back to wet snow Tuesday overnight into Wednesday as a secondary low pressure on the east coast takes over.   Temperatures will be near 1c to 2c so it is possible the Ottawa area gets quite the mix of wet snow, freezing rain and rain.

Here is some models examples showing possible snow accumulations (in inches):




Behind this storm comes more cold from late Wednesday into early next week.  This will set up Lake Effect snow for regions around Georgian Bay again.  Things look to come back towards normal come next Monday -Tuesday.  In fact current indications from the models show a pretty near normal to almost above normal temperatures for the rest of January.  However that doesn’t mean there wont be any snow opportunities.  The next storm chances look to come around January 11th, but the chance of storms cutting west again isnt out of the question.