At 67 degrees, the 1 p.m. temperature at Philadelphia International Airport was just 3 shy of the record for the date -- and 45 degrees warmer than the high exactly one week ago.
Such temperature swings often are accompanied by trouble, and that will be the case tonight, according to the National Weather Service.
The Storm Prediction Center, in Norman, Okla., has placed the entire region in the "slight risk" category for severe weather.
Even if the winds don't reach the government criterion for "severe" -- 58 m.p.h. -- tie down the deck chairs.
A wind advisory is in effect west of the Delaware River for 45 m.p.h. gusts, and a "high wind warning" is posted from the river to the Shore for 60 m.p.h. gusts.
In the afternoon forecast-discussion update, Walt Drag at the National Weather Service in Mount Holly says that a hurricane-force gust, over 74 m.p.h., isn't out of the question.
The strongest winds are expected to howl from 9 p.m. to 3 a.m.
The squall line is marching through Pennsylvania, and radar indicated strong storms near Harrisburg.
A flash-flood watch is still posted, as the ground beneath the mud layer remains frozen, and the the bare trees aren't much good for soaking up water, and that would enhance run-off.
But rainfall amounts have been trimmed back a tad from yesterday's projections, and the forecast now see under an inch.
After the front passes, winter returns, and snow showers are possible Friday, but no big snows are in the picture.