Another blast of cold air will bring one of the coldest Thanksgivings on record for some Northeast cities. A strong area of high pressure originating from the Arctic Circle is now sweeping into the Northeast, and will send temperatures plummeting toward levels you might expect on New Year's Day, not Thanksgiving Day. These will be the coldest temperature anomalies - in other words, the temperatures most below average - anywhere in the Northern Hemisphere on Thanksgiving Day. For some Northeast cities, high temperatures on Thanksgiving could be close to the coldest on record no matter what day of the month the holiday was celebrated (e.g. Nov. 22, Nov. 24, Nov. 26, etc.). The official U.S. Thanksgiving Day has been celebrated the last Thursday of November from 1863 to 1938, the next-to-last Thursday from 1939 to 1941 and the fourth Thursday from 1942 to the present. New York City has only had three Thanksgivings dating to 1870 when the high temperature failed to rise out of the 20s,