A Holiday Arctic Blast

摘要

During late December, an Arctic air mass surged south and east across the eastern two-thirds of the United States, dropping temperatures into the single digits, and even negative values, for several days. There was some "shock and awe" as winds whipped the chilled air into stinging blasts; much of the country hunkered down around space heaters and gathered the blankets closer. The first figure below shows the motive force behind this cold surge: an enormous, super-intense anticyclone (high pressure cell) that reached an astounding 1052 mb surface pressure over the northern Plains. A strong wintertime anticyclone might register at 1035-1040 mb, but anything exceeding 1050 mb is truly exceptional.