PHILADELPHIA - A powerful nor'easter slammed the region Wednesday afternoon into Thursday morning bringing sleet, rain, and the most significant snow most of the area has seen in years.The National Weather Service canceled winter storm warnings early Thursday as the storm moved out of the area, leaving scattered flurries and bitter cold temperatures behind.Wind chills are expected to stay in the 20s Thursday despite plenty of sunshine and a high temperature of 35 degrees.Those freezing temperatures could create some problems on the roadways as wet surfaces freeze over during the day and into the evening.The nor'easter first made its presence felt in Pennsylvania shortly after noon on Wednesday as the first flakes started to.