Normally I start off with a brief almanac summary from Philly Int'l, but today's event is still ongoing as I write this; case in point that the temperature is still rising a couple of degrees around 50 degrees and will still do so until about Midnight as this area of low pressure pushes away and the cold front pushes east as well. Well over an inch of rain had fallen before sunset on Sunday and that was pretty much in line that was progged to occur. A few more lighter showers will occur into the evening, but then that's it.
Once the cold front pushes through with the Arctic air behind it by early Monday morning you will feel a notice in not only the temperatures dropping, but the wind kicking up as well in excess of 15mph from the northwest(which means there will also be a wind chill so you can subtract 5-10 degrees off of the current temperature). By nightfall temperatures will get toward the lower 20s.
Now with the front offshore there will be a wave of low pressure trying to form off of the coast, but I only expect some clouds along the South Jersey and Delaware shorelines; this means that New Year's Eve will be dry(albeit seasonable) with highs around 40. Overnight and into New Year's Day itself will be cold with lows in the teens thanks to a clear sky and a light wind and highs will be just in the middle 30s. There will be a short wave trough to the north that may swing in some clouds, but otherwise we stay dry.
Thursday into Friday still looks up in the air as too many working parts have to come together; you have an Arctic front to the north and then an area of low pressure will ride along the Eastern seaboard; now these two systems have to phase(come together), but right now it may be two separate "rounds" with clouds and some snow-to-rain mixed bag along the shore Thursday afternoon, but then overnight once the front comes through and with colder air in place we can see some snow showers with light accumulations.
I always feel that forecasting this far out is only setting yourself up for failure so FIRST we have to see how much cold air filters in here these next 48 hours and how far high pressure pushes away as well(with high pressure standing firmly in place it can act like a "block" and not allow anything to get close to us).
You can check out the 7-day forecast any time at www.scottderekwx.com/forecast.html.