So, we fell just a little bit below normal for precipitation. For the coldest January ever on record in Philadelphia you have to go back to the year 1977. The normal average temperature is 30.4 degrees but that year the average temperature was just 18.6. So, we were 11.8 degrees below normal. We had a rainy morning Tuesday as the frontal system has passed through the area.
Most winter storms have a cold side and a warm side.
As a result the track of the storm determines the nature of precipitation. This storm tracked to the west of Philadelphia. We were on the warm side of this storm and that's why our precipitation fell in the form of rain. Our previous winter storms tracked to the east of Philadelphia. This put us in the cold side of the storm and we received snow instead of rain.