Records For Days Without Snow Falling Across Midwest
By Chuck Sudo in News on Dec 7, 2012 7:00PM
When we look back at the top stories of 2012, the mild winter we had in Chicago (and that’s an understatement) will be on the list. Here’s another sign of how our warm winter stacks up in history.
Chicago is two days away from breaking a record for snowless days in a calendar year. What we found most surprising about this wasn’t the number of days—280—but the year the record was set: 1994. Milwaukee is also two days away from breaking its record of 279 snow-free days, set in 1999. Some of the records are older; Des Moines matched a record set in 1889 Thursday with its 277th consecutive snow-free day. But overall, the records that are being threatened across the Midwest were set within the last decade. Accuweather's snow model for Dec. 7 shows a chance for snow falling just short of Chicago.
This is usually where global warming doomsayers and deniers begin arguing about whether climate change played a part in our increasingly precipitation-free winters and there’s plenty of time to grouse on both sides about that. Chicago magazine’s Whet Moser proposed another theory for our warm weather back in January: Space weather (via Dr. Jeff Masters).
The Arctic Oscillation (AO), and its close cousin, the North Atlantic Oscillation (which can be thought of as the North Atlantic's portion of the larger-scale AO), are climate patterns in the Northern Hemisphere defined by fluctuations in the difference of sea-level pressure in the North Atlantic between the Icelandic Low and the Azores High.... During December 2011, the NAO index was +2.52, which was the most extreme difference in pressure between Iceland and the Azores ever observed in December (records of the NAO go back to 1865.) The AO during December 2011 had its second most extreme December value on record, behind the equally unusual December of 2006.--snip—
Solar activity has increased sharply this winter compared to the past two winters, so perhaps we have seen a strong solar influence on the winter AO the past three winters. Arctic sea ice loss has been linked to the negative (cold) phase of the AO, like we observed the previous two winters. Those winters both had near-record low amounts of sunspot activity, so sea ice loss and low sunspot activity may have combined to bring a negative AO.
All current signs point to another winter of below-average snowfall in the Midwest, if Accuweather’s long-range winter forecast is to be believed. (You folks in the Northeast may want to break out your snow shovels now.)
Here in Chicago, we’ll miss the snow but the prospect of two largely dibs-free winters is something to celebrate.