Rain will be followed by sunny days in the Ohio Valley and parts of the Appalachians, but it may take two to three days for clouds and the threat of showers to inch east of the Northeast and Middle Atlantic coast early next week.
This map shows the serpentine upper air pattern and the upper air trough associated with the weekend rain storm.
The area around the Great Lakes may have fine weather with a warming trend right through the coming weekend. The difference in outcomes between the Great Lakes and the Middle Atlantic states is illustrated by these two meteograms.
As a high pressure area builds in, beautifully sunny weather should be the rule Thursday and Friday for the Great Lakes, New England and south to eastern Ohio, Pennsylvania and Maryland.
The cold flow is being cut off, though no really warm weather is yet in sight for the Great Lakes and Northeast. It is snowing this morning in parts of Maine.
A weak cold front is moving through the East this morning. There are showers near and to the east of the front. It can be seen on this 7 a.m. map.
The upper-air pattern for Sunday looks like what was called the "Polar Vortex" during winter months.
This satellite picture shows how well the cloudy and clear areas conformed to the upper air flow prediction (which was for a time 6 hours earlier than the time the picture was taken. Clouds over PA had moved farther north in that time.
A split flow aloft means Ohio Valley to New England weather will depend on flow from widely different source regions.
A cold front sweeping through the Northeast tomorrow night and early Sunday morning can promote showers and even a thunderstorm followed by a drying trend Sunday.