Monday, December 21, 2015

Holiday Heat is On in Europe, Australia, Eastern U.S.

Note that the current El Niño is stronger than usual because of global warming.

By: Bob Henson , 5:36 PM GMT on December 21, 2015

The year 2015 is is just days away from nabbing the top spot as the world’s warmest in more than a century of recordkeeping. As if to emphasize the point, the year is wrapping up with a blaze of December heat records around the globe. Some of the most exceptional numbers are being tallied over eastern North America, Europe, and Australia, which all ran quite warm in November as well. To be sure, some individual days have been standouts--and there are more of those to come--but the truly striking aspect of this month’s heat is its tenaciousness. We remain in the firm grip of a strong El Niño, as well a strongly positive North Atlantic Oscillation that’s keeping Arctic air on a tight leash at high latitudes.

It’s been an absurdly mild December over most of the United States. Figure 1 shows above-average readings across nearly all of the country. The biggest departures can be seen over the Upper Midwest. However, those smaller departures you see over the Northeast are actually more climatologically significant, because the climate there doesn’t tend to vary as sharply from day to day and week to week.


For millions of people across the southern and eastern U.S., Christmas Eve and/or Christmas Day will be the warmest in living memory, and in some cases the warmest in more than a century of recordkeeping (see this roundup for more details).


Across the North Atlantic, the warmth has been equally impressive. Earth’s longest-running climate archive, the Central England Temperature Record, has a chance at the warmest December in its 357-year history. The CET average for the month to date (12/1 – 12/19) is 9.9°C (49.8F), a phenomenal 5.1°C (9.2F) above the 1961-1990 mean and well above the warmest December on record (8.1°C in 1934 and 1974). London Heathrow has made it above 10°C (50°F) every day thus far in December, and that streak may continue through month’s end. Gardeners in Cornwall, England, have reported spring-flowering camellias in bloom months ahead of schedule.

Several other European nations are on track for a record-warm December, including the Netherlands and Germany. New all-time highs for December have been set in a number of capital cities, including Stockholm, Sweden (13.2°C); Riga, Latvia (11.8°C); Tallin, Estonia (11.7°C); and Helsinki, Finland (10.8°C). Nearly 100 stations across Germany have seen their highest daily minima for any December, said Michael Theusner (Klimahaus-Bremerhaven) in an email. “Even though not many all-time highs [for December] were broken, the duration of the warmth and its magnitude are exceptional,” he added. Germany’s monthly anomaly to date--5.4°C above average--is far beyond the peaks of around 4.0°C observed in 1934 and 1974.


[In the southern hemisphere, where it's the beginning of their summer, the equivalent of June in the Northern hemisphere.]
If it seems just a bit too mild to be wrapping presents or roasting a holiday dinner, consider the hardy souls of Port Augusta, Australia (“Gateway to the Outback”). They had to deal with record December temperatures that vaulted to 47.2°C (117.0°F) on Saturday. For the first time in any December, the city of Adelaide saw four consecutive days of highs topping 40°C (104°F). The torrid air swept into New Zealand on Monday: the South Island city of Dunedin hit a scorching 34.6°C (94.3°F), more than 4°F above its prior December record of 32.2°C.


No comments:

Post a Comment