After a chilly low of 16 at Philly International(it was in the single digits and lower teens in the suburbs) we only reached 27 for a high just before 4pm. It was a sunny day with a northwest wind between 10-15mph so the wind chill made it feel more like the middle teens.
After another cold and clear night with lows in the middle teens(single digits in the suburbs again) we'll have sunshine and some high clouds in the afternoon in advance of the low pressure with highs in the upper 20s. It is a bit weird to have a Winter Storm Warning in effect(from 10pm Wednesday until 1am Friday) when the day will be nice(albeit cold).
The early evening shall be dry with just clouds increasing; it's not until Midnight as precipitation moves in from south to north. It will be snow at the start, but as milder air aloft penetrates the snow growth layer we may see a mixture or even changeover to sleet for a while surface temperature remain sub-freezing. Once this low cranks up offshore it will push to the northeast and then pull in colder air behind it so there will be a changeover to snow on the back end for some accumulation as well. As of right now I'm thinking of between 4-8" of snow and sleet is possible across Philly along the I-95 corridor; west of there where it stays mostly snow can see higher amounts and consequently with milder air to the south and east(and some rain) we will see less amounts. There is still plenty of "wiggle room" so if this low shifts 30 miles to the east Philly stays all snow(thus higher amounts possible), BUT if the low shifts 30 miles to the west we'd be seeing some rain before that changeover to snow(leading to lower amounts).
Just remember that you can check out the rest of the seven day at www.scottderekwx.com/forecast.html.