Crossposted from Town Called Dobson
click to enlarge
In case you don't know who Jeff Masters is, he is a blogger over at Weather Underground and one of the planet's biggest brains when it comes to climatology. I started reading his stuff right after Katrina and I never knew climate science could be so riveting. Well, Jeff Masters' blog entries on it actually.
The large-scale weather pattern over the Northern Hemisphere has indeed changed to a decidedly wintery one, not only for North America, but northern Asia as well. Even Europe appears likely to get some real winter weather starting next week. I speculate that part of the reason for this shift is that the Arctic ice has finally frozen up enough to cut off the extra heat and moisture that was retarding formation of the usual cold Arctic air masses at the beginning of winter. Natural variability of the weather is probably the major factor, though.
Here in the American South, it has been crazy warm. I actually saw apple trees in West Virginia begin to bud a couple of weeks ago. Year after year now, we see crazy weather. This past year, 2006, was the warmest year on record for the United States. Master's has a very good graphic on it - truly jaw dropping.
More from Master's:
Record winter warmth in one part of the Northern Hemisphere is usually due to a sharp bend in the jet stream that creates a ridge of high pressure, allowing a warm southerly flow of air into the region. Adjacent regions have a compensating trough of low pressure that brings cold, northerly winds and below normal temperatures. This was certainly the case in January 2006, when the U.S. experienced its warmest January on record. Asia and Europe experienced a brutally cold January. Moscow hit -40°, its coldest temperature since 1979. Parts of Portugal saw their first snow since 1954. Siberia reached -70° F.
To make a long story short, the reason it took so long for winter to get here was because it took so damn long for the Arctic ice pack to freeze back over. And it won't completely freeze. Spring is in March and we are now only 40 days away from March. Now that the El Nino cycle is diminishing, who knows how that will effect the weather (and the crops) next year?
Jeff Masters, that's who.