The Lack Of Winter: Warming or Just Normal?

Winter 2019-2020 in the Mid-Atlantic from Washington D.C. to Boston, Mass has been, simply, strange or has it?

According to early winter predictions the NOAA stated in October 2019 very clearly:

“neutral conditions are in place this year and expected to persist into the spring. In the absence of El Nino or La Nina, long-term trends become a key predictor for the outlook, while other climate patterns, such as the Madden-Julian Oscillation and Arctic Oscillation (AO), will likely play a larger role in determining winter weather”

In other words, instead of La Nina or El Nino we’ve had “La Nada”. Nothing. The Pacific waters have had no impact on our winter. The jet streams have been let loose and are so divergent north and south they can’t see each other. Judah Cohen from the Atmospheric Environmental Research is an expert in the area of the AO index. He stated in his most recent blog:

“I know I sound like a broken record when I start every blog by how surprised I am by the stratospheric PV remains on the strong side of normal and even at times near or at record strong for the date. Today there has been some chatter/news about a record daily high for the AO today. But the incessant stretch of positive to strongly positive AO since late December, based on the polar cap geopotential height anomalies (PCHs) plot originated in the polar stratosphere with cold/negative PCHs/strong PV back in mid-December that propagated to the surface over a course of two weeks.”

500mb_HGT_2020021000_Days11_15.png

The graphic above shows the GEFS ensemble for temperature variation over the globe. (Courtesy of https://www.aer.com/science-research/climate-weather/arctic-oscillation/)

In other words, there has been a pool of cold air sitting on top of the North Pole just swirling around the Arctic Ocean and there has been nothing to push it south enough to allow any major, long sustaining cold weather to give the East wintry precipitation. The extent of the cold has been kept out West and it just seems to be that way this winter 2019-2020.

There have been at least eleven winters in the Philadelphia/Wilmington, DE area of fewer than four inches of snow with 1997-98 being at the top with only 0.8 inches that year. It looks like we could beat that this winter.

Thus, the predominant notion that global warming has caused this snowless winter in the NE corridor from Washington, D.C. to Boston which has had snow but not their gigantic February numbers of recent years, is by far not the culprit.

It’s just this winter.