At a Glance

Just days before Christmas, parts of the Midwest still haven't seen the season's first measurable snow.This was a near-record-long wait in parts of Iowa.Meanwhile, parts of the Deep South saw snow weeks ago from a freak winter storm.

As the Christmas holiday nears, parts of the Midwest had a near-record-long wait for theseason's first snow.

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Des Moines, Iowa, finally picked up 0.1 inch of snow on Dec. 21, their firstmeasurable snow since March 21, the day after spring officially arrived.

In 134years of records inIowa's capital city, the only time the first snow came later in the seasonwas Dec. 26, 1939.

Just to the northeast, Waterloo, Iowa, finally picked up its first measurable snow of the season on Dec. 22, the city's latest first measurable snow in 104 years, .

A number of other locations from southern South Dakota into Iowa, western Illinois, Missouri and Kansas were also awaiting their first accumulating snow as of Dec. 20, including Kansas City, St. Louisand Peoria, Illinois.

Contrast that with a swath of the South from South Texas to the Florida Panhandle to North Georgia and the Carolinas that already picked up significant snow from almost two weeks ago.

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Season snowfall estimation as of 7 a.m. EST, Dec. 20, 2017. The red dots denote some locations in the Midwest that had yet to see measurable snow in the season. The purple arrows highlight the swath of snow from Winter Storm Benji in early December.

(NOAA/NOHRSC)

Brownsville, Texas (0.3 inches), Mobile, Alabama (1 inch), and Century, Florida (2 inches), have all picked up more snow so far this season than Des Moines.

It certainly makes for a bizarre season-to-date snowfall map, shown above.

The Forgotten Snow Corridor

A number of factors have contributed to this rather snowless Corn Belt so far.

First, the jet stream since the beginning of November, and particularly in December,has .

This trajectory is favorable for manufacturing lake-effect and some other areas of snow around the Great Lakes, but is generally too far to the northeast to bring significant snow – or any precipitation – to parts of Iowa, Nebraska, Missouri and Kansas.

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Helping to force that Great Lakes jet plunge, blocking high pressure over the West hasn't allowed moist, Pacific storms to first make the journey into the West, then into the central U.S., tapping deeper Gulf moisture.

When this general pattern hasn't briefly held, either the snow track has been well to the north near the U.S.-Canadian border, or, in the weird case of , in the Deep South.

Finally, despite some brief periods of Arctic air, it has generally been warm since November in the Corn Belt, with mean temperatures3 to 7 degrees Fahrenheit above average during that time, according to the NOAA/ESRL analysis below.

Temperature departures from average (in degrees Celsius) from Nov. 1 through Dec. 17, 2017. Much of the central U.S. has been overall warmer than average during this period.

(NOAA/ESRL)

Of course, there's no guarantee this snowless start to the season will hold through Spring 2018.

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For now, though, snow throwers and snow shovels continue to gather dust in garages in parts of the nation's heartland headed into Christmas.

Jonathan Erdman is a senior meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Follow him on and .