FEBRUARY: East thaws out, focus for major cold now on West
Friday, February 1, 2019, 1:41 PM - January came in like a lamb across most of Canada, but it is going out like a lion.
I case you have forgotten, here is a quick reminder of how January began. Remember this for a similar pattern setting up in February as well. The map below shows temperature anomalies for the first ten days of January. The various shades of red highlight the regions that were warmer than normal. The very mild weather across most of Canada caused many to ask us "what happened to winter?"
Fast forward to Thursday, the final day of January, and much of central Canada is in the grips of Siberian air. The various shades of blue, green, and violet highlight colder than normal temperatures with parts of the region 15 to 20 degrees colder than normal – during the time of year when normal temperatures are at their coldest levels of the year.
So where do we go from here?
TEMPORARY PATTERN REVERSAL, FLOOD THREAT
Looking ahead to next week (February 3-10), the frigid pattern will temporarily break down from the Great Lakes to Atlantic Canada. This will bring a thaw (above freezing temperatures and rain) to southern and even northeastern Ontario, southern Quebec and much of Atlantic Canada during the first half of the week. This warming trend also raises the threat for flooding, especially in southern Ontario.
During the second half of the week, southern Ontario and southern Quebec will become the battle zone between arctic air that will attempt to press back into the region vs. the very mild weather that will continue to surge north. It is too early to know exactly where the dividing line will be between the mild air vs. the arctic air but we expect an active storm track along that boundary with rain to the south and wintry weather to the north, including the threat for ice.
While the frigid pattern relaxes for Ontario and Quebec, the frigid weather will shift to western Canada with by far the coldest weather of the season for B.C. and Alberta. This will even include the threat for snow along the south coast of B.C. The frigid weather will also spread east across the Prairies.
The frigid weather will also spread east across the Prairies. During Sunday and Monday, a winter storm will track south of the border, bringing significant to the southern Prairies, especially from Regina to Winnipeg and then spreading east into Northern Ontario.
Here is a look at the temperature pattern across Canada for next week. The various shades of blue, green and violet highlighting colder than normal temperatures.
Note, for Saskatchewan and Manitoba, this pattern reversal will not produce a meaningful difference in the weather as both patterns leave them in the grips of arctic air.
However, this reversal in the temperature pattern is expected to be temporary. As we head towards the middle of February, Arctic air will start to spread back into the Great Lakes region and Southern Quebec and milder weather will return to B.C. For Atlantic Canada, we expect that back and forth swings in temperature will come close to offsetting each other during the second half of the month.
The pattern map below is for the middle and end of February and this pattern is expected to persist for the first two weeks of March.