Wet, windy and warm Christmas for Montreal

Wednesday evening was just perfect outdoors in Montreal. Fresh snow on the ground and comfortable temperatures made it a beautiful night. Such is not the case Christmas Eve, as mild weather and heavy rain have melted away most of the snow cover leaving a soggy, muddy landscape. (ValleyWeather Photo)

Heavy rainfall warning in effect for southern Quebec.

 A deep trough of low pressure is slowly moving across the central portion of the continent, spreading a wide variety of weather along its path. A strong cold front, the leading edge of arctic air, is currently passing through the Toronto region. The front will change rain to snow as it crawls east. Behind the front, heavy snow is forecast across the snowbelt regions of the Great Lakes, including Ontario and New York.

Late Christmas Eve, low pressure is forecast to develop along the front and move north into eastern Ontario. Montreal is clearly on the warm side of the system, as we sit at 8C (47F) Thursday afternoon. The temperature will continue to rise into Christmas morning, with a record breaking high of 13C (55F) forecast for Friday. The record for the warmest Christmas in Montreal is 11.7C (53F) set all the way back in 1932. Accompanying the warm air is a swath of heavy rain. Between 30-50mm (1-2 inches) of rain is forecast for eastern Ontario and southern Quebec. Further west, the rain will change to snow Christmas Eve, with 10-15cm forecast in southern Ontario. Winds will be strong across the region, gusting between 40-60 km/h.

This storm is producing dangerous weather in many locations. Blizzard conditions occurred across southern Manitoba and northwest Ontario. In New England and New York, many of the same regions that received 100cm of snow just last week, will be receiving 50mm of rain through Friday. Widespread flood watches have been issued, with moderate to major flooding anticipated from the southern tier of New York into southern Vermont. Further south, severe thunderstorms and tornadoes are possible across the Carolinas and middle Atlantic region.

Another Green Christmas for Montreal

In Montreal, we managed 11cm of snow this week from three separate weak storm systems. Up until Thursday morning, we had our white Christmas on the ground. That is not the case any longer, as the mild weather and southeast winds have managed to melt most of the snow. The rest will disappear overnight.

Colder weather will return Friday afternoon, as the aforementioned cold front arrives in southern Quebec. Any leftover rain will taper to a few flurries, along with strong gusty west winds and dropping temperatures all the way to -10C (14F) by Saturday morning. Any wet surfaces will freeze, so use caution if out and about Christmas night.