Tony Wood, Inquirer Weather Columnist
Posted: Friday, February 20, 2015, 11:34 AM
philly.com

As we’ve written, this will be the coldest Feb. 20 in the 141-year period of record by a comfortable (or uncomfortable) margin.

After a low of 2, just missing the record of 1 set in the bitter winter of 1979, the official average temperature for Friday will come in at about 10, beating the old record, set in 1893, by a cool 4 degrees.

Based on the forecasts, the monthly average temperature will come in at just under 25 degrees, placing No. 4 on the all-time February list, and the lowest since the aforementioned 1979.

For the first 20 days of the month, 2015 is No. 15, impressive, but the same period in a recent year, 2007, was colder.

However, in 2007, the weather turned milder on the 20th; that’s not happening this time around. Temperatures will moderate during the weekend, but will remain below normal, plus a couple of inches of snow is in the forecast.

What is most extraordinary about this February is  the intensity of the late-month cold.

“It  has been a lengthy time since we’ve had this sort of sustained cold in late February,” said Paul Knight, who teaches meteorology at Penn State and is the state climatologist.

One factor, he said, might well be the extensive snow cover and absolute deep freeze to our north.

In Philly, through yesterday temperatures were averaging 26.5 degrees, or about 8.5 degrees below normal for the month, which is a profound anomaly.

But in Burlington, Vt., monthly temperatures are averaging 6.4 degrees -- better than 14 degrees below normal.

Said Knight: “We have kind of supercharged the air masses to our north. There has been plenty of opportunity to allow the air to be very cold not far away.”

The longer term outlooks keep pushing back the warm-up, and expect nothing but winter the rest of the month, particularly if the region adds to its snow cover.

This, too will end. The clocks move up in two weeks, and the spring equinox is precisely four weeks away.