Monday, December 10, 2018

Above normal temperatures forecast for Montreal in lead up to Christmas

The North Carolina National Guard patrolling in the central part of the state. Both Virginia and North Carolina were under a a state of emergency this past weekend, as a winter storm produced heavy snow, ice and rain. Powerful winds along the coast generated flooding and widespread power outages. (North Carolina National Guard)
Montreal can expect a cold week, with well below normal temperatures, and perhaps some very light snow late Tuesday. Accumulations are expected to be minimal, with perhaps 2 or 3cm. As we head towards the end of the work week, a major pattern change is expected, with much milder Pacific air beginning to flow across the country. The arctic air will be confined to extreme northern portions of Quebec. This is in contrast to the below normal temperatures we have been experiencing since early November.

Cold weather will persist in Montreal through Friday before mild Pacific air arrives. A major pattern change will lead to above normal temperatures through the Christmas holiday. However it may be marginally cold enough in Montreal, for some snow to fall in the days just before December 25th.
Above normal temperatures are expected to develop on Friday in southern Quebec, with daytime highs going above freezing and persisting throughout the weekend. A storm system developing in the lower Mississippi Valley will move towards the middle Atlantic states and eventually southern New England. Typically we would expect some snow in Montreal from this type of a setup in mid-December. In this instance, with plenty of mld air around, any snow that does fall will be short-lived, changing to rain by late Friday. We can expect showery, mild weather through the weekend, with daytime highs between 2C and 5C (36 to 41F). The normal high this week in Montreal should be -2C (28F).

Even snowplows were struggling to keep up with the record amounts of precipitation across the southern US this weekend. (NCDOT Photo)
Over the weekend, deep low pressure moving well south of our region, delivered record breaking amounts of snow from Texas to the Carolinas. Some locations in North and South Carolina reported over 50cm of snow. Numerous roads were closed, along with thousands of flight delays and cancelations. A state of emergency was declared in North Carolina and Virginia. Power was out to hundreds of thousands of homes and businesses.

White Christmas?
With very little snow on the ground in southern Quebec and metro Montreal, and plenty of mild air and rain in the forecast, a white Christmas this year may be in jeopardy. There are some indications that slightly cooler air will arrive in the week before Christmas, just cold enough to allow some snow to fall. Time will tell, we will certainly know more in the coming days, but a snowstorm on or around December 23rd in not out of the question.

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