Dry air cools quickly once the sun sets and by morning 30-35 degrees colder than the previous day's highs are not that uncommon. November is the driest month of the year in Raleigh, NC. The length of nighttime plays a role also as we approach the darkest 2 months (Nov 21-Jan 21).
After another week of mild dry weather there is expected to be a major weather pattern change for the week of Thanksgiving. This GFS forecast from NCEP depicts a cold high pressure system damming air down the Eastern Seaboard. Such a pattern will certainly be colder than average and is one that would favor precipitation as warm air aloft would tend to overrun.
|GFS Forecasts wedge of cold air dominating the eastern seaboard.|
Source: NCEP Central Operations