Yet another Winter Storm Watch is in effect for areas north and west of Philadelphia for Friday.
Early tonight, clouds will increase and light rain will develop across Delaware and Southern New Jersey.
Later on, the rain becomes widespread from Philadelphia south and east, then snow will begin north of the PA Turnpike and mix with sleet and freezing rain.
Bucks, Berks, and all counties north of that may see a significant to major snow and ice storm. From Philadelphia south and east, it will be just about all rain, and some of it will be heavy.
The storm will be riding a powerful jet stream that stretches from California and Arizona to our area. There is arctic air north of the jet stream and very warm air to the south. That huge temperature contrast is one of the ingredients making these storms so potent.
There is a lot of moisture with this storm, and any area that gets all snow would see major accumulations. Any area that has mainly sleet or freezing rain will see major ice accumulations.
Most areas under the watch will see a bit of both, which is likely to cause problems from Friday morning through the afternoon, at least.
For the morning rush Friday, you can expect temperatures at or below freezing. That will keep roads slippery in Lehigh and Hampton County.
Rain may move as far north as Allentown, but spotty areas of temperatures below freezing could keep roads icy through the morning.
Friday afternoon, the precipitation is expected to come to an end.
Temperatures will drop back below freezing by Saturday morning, but roads should have dried out by then.
Another Winter Storm will affect the area Sunday and that one should bring snow even to the Philadelphia area before changing to rain.