The Family Day forecast you'll want to read, right here
Sunday, February 19, 2017, 9:13 AM - Looking back at 2016 and 2015, both of these years had bitterly cold Family Day weekends with some temperature records set. Unlike these Family Day weekends of yesteryear, the pattern taking shape for this year is quite different.
The first two images below show the upper air pattern from the evening of Feb. 14 into the morning of Feb.15, 2015 and its associated temperature anomaly pattern.
FIRST, A LOOK BACK
Remember that the anomalies do not show actual temperatures, but a departure from the climate norm. Also, note that this was the coldest morning of the Family day weekend in 2015. The pattern that was in place had a lobe of the polar vortex in place across southern Ontario and through much of eastern Canada.
This pattern not only resulted in the coldest temperature for the 2015 Family Day weekend, but it was also the coldest morning low recorded for the entire month of February 2015.
Below, the first image shows the upper air pattern from the evening of Feb. 12 into the morning of Feb. 13, 2016. Notice how it's quite similar to the pattern observed in 2015 with a lobe of the polar vortex in place across the eastern half of the country.
So, it should come as no surprise that the temperature anomaly pattern observed with this pattern is again quite similar to that from 2015 with widespread cold across the east. Also, note that Feb. 13 was the coldest day for February of 2016.
Here’s where things turn a little odd. Below shows the upper air pattern from Wednesday evening into Thursday morning. Notice how it is rather similar to what was observed in 2015 and 2016. A lobe of the polar vortex is currently in place across the eastern half of the country.
Then that begs the question: Where is the cold?
Below shows the temperature anomalies for the same period as mentioned above. Other than a little sliver of cooler air over northwestern Ontario, temperatures are either near or above seasonal across the eastern half of the country. There are a few subtleties that can explain this.
With the current pattern, there is little to no cross polar flow, there is still a strong Pacific influence that is modifying any Arctic air heading this way, and the bulk of the real cold air is trapped over Siberia.
The current pattern in place is not tapping into this source and thus, we are left with a modified Arctic air mass. So far for February 2017 only Feb. 8 through to Feb. 10 has been able to muster up anything close to seasonal to slightly below seasonal. Looking ahead to the upcoming Family Day weekend and the week to follow, the remainder of February 2017 is certainly not going to be like the previous two years.
AND NOW, WHAT TO EXPECT THIS YEAR
Unlike the Family Day weekends of 2015 and 2016, the pattern taking shape for this year is quite different.
A large ridge in the upper air pattern is expected to develop. Warm air will be drawn northward from the southern U.S., which will send us a taste of spring through the weekend. Friday the milder air started to push into southwestern and northwestern Ontario with afternoon highs reaching into the mid-single digits.
Saturday into Sunday saw the warmth extend up into northeastern Ontario with highs into the mid-single digits, approaching the high single digit mark across southeastern Ontario, and southern Ontario getting into the low to mid-teens, nearing 20oC for Windsor and Sarnia both Saturday and Sunday.
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By Sunday, the warmth also extended into Atlantic Canada with temperatures across most of the Maritimes and eastern Newfoundland getting above the freezing mark and into the mid-to-high single digits across Nova Scotia.
Temperatures will decrease slightly for Family Day on Monday, but it will still be well above seasonal for the eastern half of the country.
Looking ahead through the rest of the month, the mild air is likely to remain in place. The first image below shows the average upper air pattern expected from Tuesday of next week through to just about the end of the month (Feb. 26). Note that the warmer orange colours indicate higher heights, or in other words, more of a ridge pattern.
With a more persistent ridge pattern in place the warmth is expected to stick around as well. Below shows the average temperature anomalies for the same period, Feb. 21 through the Feb. 26. On average, temperatures are likely to remain nearly 2oC to about 8oC above normal through the rest of February.