With above-average warmth throughout the Northeast, several cities in the region face top-10 warm Decembers, according to climatologists at Cornell's Northeast Regional Climate Center (NRCC). Boston, however, has the best chance of setting a new high average temperature record for the month.

If the warmth continues, New York City, Buffalo, Syracuse, Ithaca, Scranton, Pa., and Erie, Pa., all could have a near-record warm month. If it remains unusually warm until New Year's Eve, Watertown, N.Y., will have its warmest December on record. Caribou, Maine, normally a foregone conclusion for a white Christmas, may have its fourth warmest December ever.

Among the big cities, Boston has the best chance of setting a new average temperature record. Through Dec. 19, Boston averaged 42.3 degrees -- 5.7 degrees above average. The record average for December in Boston is 40.7 degrees. The city will need to average 5.8 degrees above normal each day to break the record.

Currently, the Northeast is sandwiched between the effects of an El Nino event in the Pacific Ocean and the positive phase of the North Atlantic oscillation. In effect, the Northeast is a dry and warm enclave, said Art DeGaetano, Cornell associate professor of climatology and director of the NRCC.

The North Atlantic oscillation affects wind currents and storm tracks over North America during the winter months, and it is now suppressing Arctic air from plunging into the northern tier of the eastern United States.

"There were warm Decembers in the 1880s and the 1920s, and certainly there was a warm December in 2001," said DeGaetano. The warm Decembers in the 1880s and the 1920s resulted from similar El Nino and North Atlantic oscillations. The meteorological reason for the December 2001 warmth is still a matter of scientific debate, he said.

The NRCC has developed a temperature-departure chart for the month: http://www.news.cornell.edu/pressoffice1/Dec06/warm.dec.table.shtml.