The December 1989 Cold Wave

Much of the United States was chilly as the second half of December 1989 began. A powerful and persistent upper level low pressure system set up over the southern Canadian provinces, keeping much of the U.S. under the influence of a huge trough. In Birmingham, the mercury peaked at 70F on the 6th followed by a cool down behind a cold front. Readings would remain at or below normal until the final week of the month.

But in the week leading up to Christmas, forecasters foresaw an episode of the Siberian Express unfolding. Dramatic predictions of intense cold diving all the way to the Gulf Coast dominated the headlines. On the morning of Tuesday, December 21, 1989, a powerful 1052 millibar high was over southern Saskatchewan. At Swift Current, the thermometer read -39F and the barometer 1053.2 millibars. Arctic air was plunging south behind a cold front that was pushing through Memphis. In Birmingham, it was 42F. In Memphis, it was 19F. By the morning of the 22nd, the mercury stood at 15F at Birmingham. It never got any higher that day. By midnight, the mercury would be down to 4F. It was -3F in Memphis and -10F in Nashville that cold morning.

For Birmingham, the coldest morning would be the 23rd, when the mercury dropped to 1F. Along the Gulf Coast, it was an amazing 7F in Houston, 11F in Lake Charles, 11F in New Orleans and 10F in Pensacola. 122 cities across the central and eastern United States reported record low temperatures for December 23rd. Forty one of the cities also record lows for the month of December, some which had only been set the day before. It was -4F at San Angelo TX and -26F at Topeka KS, all establishing all-time record lows for those locations.

Here is the 500 mb weather map for the morning of the 23rd.

Here is the surface map.

Even more amazing was the snowfall that was occurring over the eastern Florida Panhandle and Florida Peninsula up the Georgia Coast. A Gulf low that crossed the Sunshine State was responsible. It snowed in Tampa and Daytona Beach. It was the most widespread snowstorm in the history of the state. Two inches fell at Savannah and 3.9 inches in Charleston, South Carolina. As the low moved up the coast, it intensified, dumping an astonishing 15 inches of snow at Wilmington, North Carolina and 13.3 inches at Cape Hatteras.

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