The jet stream has gone loopy. Instead of the mostly west-to-east pattern that it has been stuck in recently the jet is now flowing in a series of large loops that extend way north and way south. Today we are under a ridge of high pressure at the jet stream level and a high pressure system down here on the ground. Add those up and you get brilliantly clear skies and a near-normal high of 50 degrees.
The flip side of the stacked high pressure systems is that they are allowing lots of moisture from the Gulf of Mexico to feed into a storm that's brewing on the Great Plains. The storm will be bumping up against that high pressure tomorrow, bringing with it warm air and the potential for lots of rain. Tomorrow's high in the upper 50s means November will be the ninth straight warmer than normal month!
It looks like rain will hold off until after tomorrow evening's Rockefeller Center tree lighting festivities. Wednesday will again be warm but the East Coast is likely to get socked with 1-2 inches of wind-driven rain during the day. The rain should be done by midnight Wednesday. Behind the cold front the city should see several cool, clear days. Look for highs in the lower to mid 40s and lows close to the freezing mark through next weekend.