Serious winter ahead

As our online story notes, snow is all but a certainty for Thursday night into Friday as it appears that some of the recent models want to squeeze out a tad more juice from the approaching system.

The Accu-Weather call for 3 to 6 inches is quite similar to the National Weather Service early estimate of 3 to 5. That's an unusual consensus 36 hours away. 

More certain than the snow, however, is the arrival of the coldest air of the season, so this is the day you want to clear the slop off your driveways and walkways.

Temperatures will struggle to get to freezing tomorrow and Friday, and look to be locked in the 20s on the weekend. The current forecast low for Sunday morning is 6 for Philadelphia.

That would be the lowest reading since the 7 on Jan. 17, 2009.

In the last decade, singe-digit readings have been scarce. In the period of record dating to the 1870s, single digits have occurred roughly 3 or 4 times a winter on average. Since 2001, however, it has failed to go below 10 in half the winters.

As for zero readings, Philadelphia has registered a total of 45 of them dating to the 1870s, but not a single one since the 5 below registered on this date in 1994.

Right now, it's in the 40s, so get shoveling.