Wednesday, January 11, 2012

First winter storm?

We have used today's headline more than once this winter, but it appears we may be heading for some true winter weather. As mentioned yesterday, up to this point in the season, the largest single snow event has been around 8cm for Montreal. We are looking at at least that into Thursday evening. We will start with sunny skies today and cold temperatures as arctic high pressure crests over the region. Ile Perrot is -14C this morning with a light northerly breeze making it feel more like -18C. Clouds will be on the increase late today as a complex area of low pressure approaches Ontario and Quebec from the south and west. By Friday morning we may be dealing with at least three separate area of low pressure. They will combine to bring us two separate precipitation events over a 48 hour period. Snow will overspread the area from south to north on Thursday with highest amount, up to 10cm along the US border, closer to 5cm by Thursday evening for Montreal. The snow will be accompanied by a brisk northeast breeze causing some blowing snow. A break in the action late Thursday before a second round of more significant snow affects the entire region on Friday. Amounts are a little hard to pinpoint at this time, but at least 10cm should fall in Quebec and eastern Ontario and perhaps more. At this time the only warnings in place are south of the border across New England and New York for a mix of snow and freezing rain Thursday. I expect warnings or advisories will be needed for a portion of Ontario and Quebec by later today or Thursday.

Basically in short look for snow covered roads beginning Thursday and lasting through Friday in all our regions along with gusty winds and blowing snow. Further south and west freezing rain will mix in, with just plain rain for Toronto. On Friday it will snow in all areas. Temperatures will drop Friday with likely the coldest night of the winter on Saturday night. Looking ahead more of the same type of weather is expected for week, just in case you thought winter was over, or never coming! This is very much a developing weather event with lots of uncertainty so watch for updates here and via twitter.

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