The headline startled me. Living in the Eastern US I had no idea. But here's what they say: Earth Records Its Warmest Winter on Record
The winter of 2014-15 was the warmest on record worldwide, according to the state of the climate report released by the National Oceanic Atmospheric Administration (NOAA) on Wednesday.
NOAA says that December through February – for meteorological record-keeping purposes, winter is defined as those three months in the Northern Hemisphere – was 1.42 degrees Fahrenheit above the 20th-century average for all land and ocean areas. This tops the previous warmest winter of 2007 by 0.05 degrees Fahrenheit. Global temperature records are available for the period 1880-2015.
Individually, here is how each month ranked for the earth:
- December 2014: Warmest on record.
- January 2015: Second warmest on record.
- February 2015: Second warmest on record.
Though it was a cold winter overall in eastern North America, including the United States, the Northern Hemisphere also saw its warmest winter on record. This was due to widespread above-average temperatures in western North America, Europe and Asia. NOAA says that record warmth was observed in the western United States, portions of central Siberia and eastern Mongolia.
Read on below for more.
Even the US had some hot spots. Twenty cities for example:
The winter of 2014-15 has been so exceptionally and persistently warm across the western third of the United States that more than 20 cities have tied or broken all-time records for the warmest meteorological winter (Dec. 1 through Feb. 28/29) on record.
A number of cities clinched the record several days ago as they outpaced the previous record-warm winter by such a large margin that they would have had to see subzero temperatures not to end the winter with the new winter warmth record.
The warmth has not been all good news in the West – snowpack has been well below average in the Cascades and is now at record-low levels for late February in the Sierra Nevada.
Since snow is a major source of water out west, it seems like the Northeast got all the water needed out there. Even with the cold in the eastern US
For the United States alone, winter 2014-15 was the 19th warmest on record.
It seems like the changing patterns are part of a larger system of events:
Weird Winter Weather Plot Thickens as Arctic Swiftly Warms
Yes, droughts, cold and snowstorms have happened before, but the persistence of this pattern over North America is starting to raise eyebrows. Is climate change at work here?
Wavier jet stream
One thing we do know is that the polar jet stream—a fast river of wind up where jets fly that circumnavigates the northern hemisphere—has been doing some odd things in recent years.
Rather than circling in a relatively straight path, the jet stream has meandered more in north-south waves. In the west, it’s been bulging northward, arguably since December 2013—a pattern dubbed the “Ridiculously Resilient Ridge” by meteorologists. In the east, we’ve seen its southern-dipping counterpart, which I call the “Terribly Tenacious Trough.”
Besides having fun with words the narrative signals changes in patterns that were relatively stable for some time. These changes may be around for a while:
A number of recent studies have found what appears to be a solid connection between sea-ice loss in an area north of western Russia during the fall and a rash of abnormally cold winters in central Asia. The loss of sea ice favors a northward bulge in the jet stream, which strengthens surface high pressure to the east. That shift pumps cold Arctic air southward into central Asia.
Other studies suggest that Arctic warming in summer leads to a split jet stream—or two separated rivers of wind—which tends to trap the waves. Those stationary waves cause weather conditions to remain “stuck” for long periods, increasing the likelihood of extreme heat waves, droughts and flooding events in Eurasia and North America.
Our own new work, published last month in Environmental Research Letters, uses a variety of new metrics to show that the jet stream is becoming wavier and that rapid Arctic warming is playing a role. If these results are confirmed, then we’ll see our weather patterns become more persistent.
In other words, Ridiculously Resilient Ridges and Terribly Tenacious Troughs may become the norm, along with the weather woes they cause.
It all brings to mind the old Chinese curse:"May you live in interesting times".