Here is today's video forecast.
This is a draft map shows predicted snow amounts and starting times. Note how a preliminary patch of snow advances well northward through Pennsylvania before the main precipitation reaches central New Jersey. Eventually, coastal areas will have the heaviest snow. Early tomorrow, gale-force winds and falling, swirling and drifting snow could cause blizzard conditions in extreme eastern Massachusetts (especially Cape Cod).
After tomorrow, a warming trend will spread eastward from the Plains. Instead of snow, thunderstorms and the possibility of severe weather may become the primary focus of attention. The blue line made of the S character shows where the National Weather Service Storm Prediction Center says the greatest risk of severe thunderstorms will be located on Thursday and Thursday night.
This map is a spaghetti plot showing the upper air currents predicted by members of last night's GFS ensembles. In looking at each line, you see variations, but they all show the idea of major trough centered east of the middle of the country on Christmas Eve.
Any storm in the Northeast could be disruptive for travel, whether it turns out to be rain and fog or snow and ice. If a strong storm develops, the best chance for snow on Wednesday will be over the central or northern Great Lakes region. This map is last night's GFS operational solution for 7 p.m. ET Christmas Eve.
The map below shows the low pressure area and cold front now moving into the East. Looking at the temperatures, truly cold air is well behind the cold front. This is in line with the idea that the front itself is the leading edge of the change to colder conditions.
The following map shows why areas to be affected by the cold front will not have a long period of rain. However, along and north of the storm center, the precipitation will last longer.
The satellite picture shows a deck of clouds all the way along I-80 from Nebraska to New Jersey with few holes along the way. However, nobody in the cloud zone is having any substantial precipitation. There was some spotty freezing drizzle this morning.
My back yard in the middle of Pennsylvania looked like a winter wonderland this morning as shown in the photo below. In many areas from western and central New York south into Pennsylvania, snow and ice patches on the roads made it a potential blunderland for motorists.