In the space of 12 hours, much of the region saw temperature swings of 15-20 degrees in both directions as milder air surged north on Tuesday night with the incoming storm system, only to see it just as quickly depart as the low pressure center responsible for the warm surge passed by and a cold front pushed on through.
Philadelphia warmed from 40 at 8 PM on Tuesday night to 64 during the 2 AM hour on Wednesday morning, only to see temperatures slowly crash through the course of the day as colder air oozed back in. In fact, it sleeted at a couple of points in the afternoon hours in the city (and snowed in many other spots), resulting in a rare "60 to frozen precip" day in the city. We last did it on January 31st as the region picked up a coating of snow after being in the 60's very early in the morning hours before a cold front crashed through.
Temperature jumps north and west were not as dramatic -- Allentown went from 33 to 48 overnight for instance as the low tracked just east of the Lehigh Valley -- but for the rest of us, Tuesday night into Wednesday provided a very mild and wild temperature swing...bringing fleeting warmth for just a little bit.