 As it entered the warm waters of the Gulf Stream in the Atlantic Ocean, it began to rapidly intensify, exhibiting traits of a tropical system, including the formation of an eye.It attained a pressure of 970 millibars on December 23 and 24, and after moving northward, it came ashore near New York City on Christmas Eve.Because of the uncertain nature of the storm, the National Hurricane Center (NHC) did not classify it as a tropical cyclone.