Just How Cold Is Philadelphia Going to Get?

Don't fool yourself: A chill is on the way.

Yes, it might feel like spring outside in Philadelphia. It’s definitely not going to stay that way—temps will drop all day and into extreme conditions overnight.  Here’s the National Weather Service:

WIND CHILL ADVISORY IN EFFECT FROM 1 AM TO NOON EST TUESDAY...THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINDCHILL ADVISORY. IT IS IN EFFECT FROM 100 AM TUESDAY UNTIL NOON ONTUESDAY.* LOCATIONS..EXTREME SOUTHEASTERN PENNSYLVANIA, SOUTHERN NEW  JERSEY, DELAWARE AND NORTHEASTERN MARYLAND.* HAZARD TYPES...DANGEROUS COLD AND WIND.* WIND CHILL VALUES....AS LOW AS MINUS 10 TO MINUS 15.* TIMING...LATE TONIGHT THROUGH MIDDAY TUESDAY.* IMPACTS...PROLONGED EXPOSURE TO THE DANGEROUS COLD AND WIND MAY  LEAD TO HYPOTHERMIA AND FROSTBITE.PRECAUTIONARY/PREPAREDNESS ACTIONS...THIS WIND CHILL ADVISORY MEANS THAT THE COMBINATION OF VERY COLDAIR AND STRONG WINDS WILL CREATE DANGEROUSLY LOW WIND CHILLVALUES. LIMIT YOUR TIME OUT OF DOORS IF POSSIBLE.