Snowmelt: Flood of trouble?

This morning's quick-hitting snowfall is disappearing about as fast as it came. We watched it slide off cars like creamed icing sliding off the face of someone who has just been pied.

An impressive melt is underway, and it will gain considerable momentum the rest of the workweek, perhaps a splash too much on Friday, when temperatures make a run at 60 and thunderstorms are possible.

The water content of the snow-and-ice to the north and west of the city is prodigious, exceeding 4 inches in parts of the city and Bucks and Montgomery Counties.

With a fresh coating, the reported snowpack this morning generally ranged from 15 to 25 inches in the immediate Philadelphia.

Soon, familiar objects will reappear in yards all over the region, and, eventually, all this is going to rejoin the water cycle.

Before it does, it is likely to cause at least some minor flooding issues, said Gary Szatkowski, meteorologist in charge of the National Weather Service Office in Mount Holly. "I'd be surprised if it didn't," he said.

Fortunately, the liquid amounts in the snowpack  in the vicinity of the Delaware River headwaters isn't as robust as it is around here.

Also, fortunately, Friday's rainfall amounts don't look too scary, but a rapid melt, combined with a downpour, could set off flashier streams, such as the Perkiomen and Neshaminy Creeks.

Recall that in the cosmic floods of 1996 after the record snowfall, less than an inch of rain was measured in Philadelphia. That flooding was all about rapid snow-melt.

A snow-eating fog, said Szatkowski, could make it all vanish in a hurry.

Even in the absence of heavy rain or rapid melt, Friday could be an ugly day on the region's roads. Expect ice-and-snow clogged drains to cause considerable ponding.

Said Szatkowski: "I'd recommend that people get out there and adopt a storm drain."