Frigid winter in Northeast leaves behind inverse footprints from January’s snowstorms

For weeks, the wintry aftermath of snowstorms in late January left much of the Northeast blanketed with snow and ice as temperatures steadily held below freezing.

The snowpack is only now melting significantly, and in some places, it’s leaving behind the remnants of footsteps from the initial mix of snow and sleet that fell last month. 

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The National Weather Service in Mount Holly posted photos Thursday that show odd-looking examples of inverse tracks in the snow in Trenton. The phenomenon is caused by the sequence of sleet falling after snow. The footprints where people walked during the initial snowfall got filled with pockets of ice from the sleet, and now the surrounding snow is melting faster than the icy impressions of footsteps.

“When the sleet fell, a lot of it ended up bouncing into the footprints and knocking some snow in,” NWS meteorologist Ray Martin said. “You get a lot of excess accumulation of the sleet in the footprints. Obviously, it was very cold and everything was stable for a while, but now that it’s melting, you have the extra sleet in those footprints. That’s a much larger mass of ice. There’s a lot more water in that pool of compacted sleet than there is in the regular snowpack.”

Several people who saw NWS’s Facebook post replied with photos of inverse footprints they spotted in their own communities. As remnants of winter storms go, they’re a lot more palatable than the piles of weeks-old dog poop that people are finding in their neighborhoods in the wake of the melted snow.

A seasonlong cold spell

Large parts of the Northeast and Mid-Atlantic regions are in the midst of the coldest winter in recent memory.

Based on temperatures recorded at the Philly airport from the start of December through Feb. 19, this has been the coldest winter in the city since 2011. The nine-day streak of below-freezing temperatures from late January into February was the longest recorded since 2004. (The record still stands at 15 consecutive days in 1979 and 1961.)

Rivers, lakes and other bodies of water remained frozen for weeks during the cold snap — and many cities in the Northeast are still icy. Lake Erie, the shallowest of the Great Lakes, was 96% frozen on Feb. 5. Drone footage from the lake showed an 80-mile-long fracture that formed Feb. 8, extending from Port Burwell, Ontario, to just outside Cleveland.

The meteorological winter is measured from Dec. 1 through the end of February, so the rest of the month will determine how this winter stacks up historically, Martin said.

It might not be over

The Philadelphia region could be in line for more snow. The current forecast calls for a wintery mix starting Sunday afternoon and continuing into Monday morning. The high Sunday is expected to hit 39 degrees with a low of 31. Monday’s high is 39 degrees with a low of 26.