Monday, January 23, 2012

Light freezing rain possible

Environment Canada has hoisted freezing rain warnings once again as low pressure and a warm front approach Quebec from the southwest US. The warnings are for up to 5mm of freezing rain but are for areas north of Montreal. The southwest portion of the province along with Montreal is excluded from the advisory but we will have to watch that carefully as the day progresses. The storm is forecast to pass well to our north and west leaving the city in the mild air. The problem will be the light northeast winds, as always, at the surface of the St. Lawrence Valley. This morning for example Montreal is -7C while Burlington, Vermont is -2C. The onset of precipitation should be this afternoon, so hopefully the surface temperatures will have warmed by then.

Regardless of the temperature, most parking lots and sidewalks are icy already so any liquid precipitation on top will only make it more slick. Once the warmer air moves in on gusty southwest winds to 60km/h this evening, the temperature will surge overnight to a mild plus 5C (41F). It will cool only slightly on Tuesday with the passage of a cold front down to the 0C mark. This cold font has lots of energy with it and is producing severe weather and even tornadoes across portions of the lower Mississippi Valley. It is not out of the realm of possibility that we could have a rumble or two of thunder this evening in eastern Ontario and southern Quebec as the front races through. High pressure will build into the region for Wednesday with seasonable highs just below freezing before another storm system brings a chance for light snow by late Thursday.

As mentioned severe weather is moving across the south. Portions of Alabama, Mississippi and Georgia have had severe thunderstorms and tornadoes overnight with damage and injuries reported. A tornado watch remains posted for a portion of the area early this morning. You can view some video of the overnight storms HERE.

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