This winter has been one of the coldest on record in the eastern United States. But you’ll get a very different view of winter 2013-14 if you ask a Muscovite than if you ask a Minnesotan.
The Averages That We Call Climate
What goes up must come down; things even out. That’s true of the weather. Despite global warming, the temperature averaged over the globe for an entire year changes by only a fraction of a degree from one year to the next. The atmosphere can only hold so much water vapor, so the average yearly precipitation doesn’t change much either.
This Winter in the U.S. and Around the Northern Hemisphere
This has been a cold winter in the midwest, but not a historic one: top ten in most cities. But snowfall more than double the normal has made it seem like a very severe winter. If he had been alive and living in Chicago this year, Henny Youngman would have said, “Take this winter. Please.” But in other parts of the world the weather has been very different.
Let’s look at some temperature data from major cities in North America, Europe, and Asia. The metric I’ve chosen is the number of days on which the high temperature exceeded the average for the date for the period Jan. 1 through March 16, 2014, a total of 75 days.
- Chicago, 18 days. Only seven of these days were after February 1.
- London, 73 days. This has been a remarkable spell of warm weather which began more than three months ago. Since November 26, a total of 110 days, the high temperature has failed to reach the average only three times, none in February or so far in March. 107 to three and 44 to zero are pretty lopsided scores.
- Tokyo, 38 days. Somebody’s got to be average..
- Beijing, 47 days. All but four days in January were above average. Safe to forecast smog.
- Moscow, 59 days. From January 17-31, every day was below normal. Outside of that cold spell, every day but one has been above normal, including the last 43 days in a row.
The one thing that stands out in these data is the remarkable persistence of the weather this winter. And it has been true of precipitation as well as temperature. California has remained dry, while England has been especially soggy.
Speaking about the storms that brought flooding to England in December and January, the UK Met Office said, “This series of winter storms has been exceptional in its duration.” Typical British understatement.
Is The Abnormal Weather This Winter Connected To Global Warming?
Though it has long been recognized that the weather has memory and tends to repeat what it’s doing, meteorologists now suspect that this trend is getting more pronounced. Some computer models that incorporate increases in greenhouse gases predict increasing persistence of the weather, but it is too soon to say with any certainty that this is a manifestation of global warming. What can be said with certainty is that worldwide this has been one of the warmest winters on record. Go tell that to a Minnesotan.
Hot Off The Press
The jet stream pattern that has controlled the weather over the northern hemisphere this winter appeared ready to break down last week. Pressures fell at the pole and forecasts showed the polar vortex weakening over the United States. The downstream ridge which brought such mild weather to Europe would flatten and overall temperatures would revert to more normal readings.
No such luck if you live in the Great Lakes or New England. Latest forecasts are coalescing around at least a couple more weeks of winter in the eastern U.S. Punxsutawney Phil was supposed to come out yesterday, but he may be inclined to hide for a while longer.