2006: warmest year on record in the U.S.

By: Dr. Jeff Masters , 9:18 PM GMT on January 09, 2007

Share this Blog
2
+

The United States recorded its warmest year ever in 2006, according to today's report issued by the National Climatic Data Center (NCDC). The 2006 annual average temperature was 55�F, 2.2�F (1.2�C) above the 20th Century mean and 0.07�F (0.04�C) warmer than the previous warmest year, 1998. The NCDC had estimated that 2006 would be the 3rd warmest year in U.S. history last month, but an unusually warm December pushed 2006 to the top. It was the warmest December on record in the Northeast U.S., and the 4th warmest December for the country as a whole. Only 1939, 1957, and 1933 had warmer Decembers. However, the statistics partially hide the extraordinary warmth that began on December 10 and continued until January 6, when New York City tied their all-time record January high temperature of 72�. During the month ending January 6, the Northeast was 14 �F above average, and the U.S. as a whole was 7� above average.



No cause for alarm?
"No cause for alarm. Enjoy it while you have it," said Mike Halpert, head of forecast operations at the National Oceanic & Atmospheric Administration's Climate Prediction Center, in a story run by CNN just before New York City's record warmth. The story continued, "The weather is prone to short-term fluctuations, and forecasters said the mild winter does not necessarily mean global warming is upon us. In fact, the Plains have been hit by back-to-back blizzards in the past two weeks." True, the weather across most of the U.S. has finally cooled off this week, and the rest of January should have near average temperatures. And I agree that one warm month of winter in one country in its warmest year in 112 years of record keeping is not evidence of global warming, particularly when there is a moderate El Nino episode going on. An El Nino can lead to significantly warmer winters in the U.S.--exceptional December warmth has also occurred in 1877, 1939, and 1957, all of which were moderate or strong El Nino years. I've plotted up a comparison of temperatures in December of 1957 vs 2006 (Figure 1), and one can see that the unusual warmth of December 2006 does have historical precedent. Taking a look at average U.S. December temperatures for all years in the historical record (Figure 2), we see that these temperatures do show quite a bit of noise, and there is no evidence of dramatic warming in the past 30 years.


Figure 1. Comparison of the departure of average temperature from normal for December 1957 (the the second warmest December on record in the U.S.) and December 2006. Image credit: NOAA.

Figure 2. Average December temperatures for the U.S. from 1895 to 2006. Image credit: National Climatic Data Center.

Rolling thirteens with the weather dice
Take a look at the trend December temperatures in Figure 2. It shows that the average temperature has warmed a little more than 1� F in the past century. It may not seem like much, but that is enough to significantly load the dice in favor of warmer winters. Six of the ten warmest U.S. winters on record have occurred in the past 15 years. Month long spells where winter is seemingly absent--as also occurred in January 2006, the warmest January in U.S. history--have become more common. Keep in mind that the weather of January of 2006--which blew away the previous record for warmest January by a huge margin (2� F)--occurred during a La Nina year, not an El Nino. What concerns me most is that the warming trend is not isolated to the U.S. The 1� F rise in temperatures the past century has occurred world-wide, thanks to global warming, and the temperature increase has been much higher in the Arctic--something the climate models have predicted would occur as a telltale sign of the human-caused addition of greenhouse gases to the atmosphere. In the past, an exceptionally warm winter month in the U.S., like December 1957 (Figure 3), was offset by much cooler weather elsewhere, such as we see in Alaska, Greenland, and northern Siberia. However, December 2006 had no such offsetting cool temperatures--it was more than 1� C above average over almost all the land areas of the Northern Hemisphere north of 40� north latitude (Figure 4). Colorado, whose three blizzards have been widely cited as evidence that winter has been severe elsewhere, still recorded temperatures about 1� C above normal in December 2006.


Figure 3. Global departure of temperature from average for December 1957, the second warmest December on record in the U.S. Note that the exceptionally warm temperatures over the U.S. are offset by much cooler weather elsewhere, such as in Alaska, Greenland, and northern Siberia.

Figure 4. Global departure of temperature from average for December 2006. Note that the almost the entire globe north of 40� north latitude was more than 1� C above average, with large areas more than 6� C (11� F) above average.

All this unusual heat in the northern high latitudes is going to significantly slow down the formation of ice over the Arctic Ocean this winter. Furthermore, the lack of the usual snows across the Arctic may allow the snowpack to melt much earlier than normal in spring, resulting in more record warmth in the Arctic this summer. Arctic sea ice coverage, already down 20% in the past 20 years, is likely to continue to shrink in 2007. As sea ice melts in response to rising temperatures, it creates a positive feedback loop: melting ice means more of the dark ocean is exposed, allowing it to absorb more of the sun's energy, further increasing air temperatures, ocean temperatures, and ice melt. The observed changes in the ice cover (Figure 5) indicate that this feedback is now starting to take hold, and the weather dice will continue to get more loaded towards rolling higher numbers in 2007. I do think we're due for a cold winter next year--part of the warmth of the past two winters is probably due to the normal random fluctuations in the weather, and Nature has been rolling twelves more often than snake eyes of late. However, we're not going to see snake eyes too much more. December's weather in the Northeast U.S. may have been a case of the weather dice coming up thirteen--weather not seen on the planet since before the Ice Age began, 118,000 years ago. The weather dice will start rolling an increasing number of thirteens in coming years, and an ice-free Arctic Ocean in summertime by 2040 is a very real possibility, as indicated by computer modelling studies published in the Journal of Geophysical Research last month. This possibility is cause for alarm, and I, for one, had a lot of trouble enjoying the phenomenally warm weather of the past month here in Michigan.


Figure 5. Percent change in coverage of Arctic sea ice in Decembers from 1979-2006, compared to the 1979-2000 average. The Polar Ice Cap has shrunk by about 15% in December, and 20% in summer, over the past 20 years. Image credit: National Snow and Ice Data Center.

Check out the realclimate.org post on this winter's anomalous warmth.

I'll be back Thursday afternoon or Friday with a look at the status of El Nino. Will it still be around during hurricane season?

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 449 - 399

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15Blog Index

448. Patrap
6:09 PM CST on January 10, 2007
Map showing where I was...On the Canal right side..south of Lake.Link
Member Since: July 3, 2005 Posts: 419 Comments: 127355
447. Patrap
6:07 PM CST on January 10, 2007
Was sitting here on Levee..comet was to my left..over Swamps..7
Member Since: July 3, 2005 Posts: 419 Comments: 127355
446. Patrap
6:06 PM CST on January 10, 2007
HAd trouble finding it..was looking too far west.Friend called and zeroed me in..was lucky.Plenty of Haze was Low on the Horizon.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
444. FUMBLE
10:27 PM GMT on January 10, 2007
what about SOFeXto reverse the co2 in the atmosphere?
Member Since: Posts: Comments:
441. Randrewl
12:02 AM GMT on January 11, 2007
I had a nice view of dark clouds...no comet. Thanks for the photos Pat.
Member Since: Posts: Comments:
440. Skyepony (Mod)
11:58 PM GMT on January 10, 2007
Oh you guys with snow could make a killin this winter..lol

Online snow sellers find bidders and buyer

I think I finally saw that comet.
Member Since: Posts: Comments:
439. Patrap
5:56 PM CST on January 10, 2007
It faded fast in the sw...as the Dusk moved in..e
Member Since: July 3, 2005 Posts: 419 Comments: 127355
438. Skyepony (Mod)
11:53 PM GMT on January 10, 2007
CP) The devastation in Stanley Park and the wacky
weather across Canada is a wake-up call for Canadians on
the potential dangers of climate change, Federal
Environment Minister John Baird said Monday.
Member Since: Posts: Comments:
437. Patrap
5:54 PM CST on January 10, 2007
Comet McNaught ..I spied it in the SW..low..about 11 degrees above Horizion.at5:35pm cst7
Member Since: July 3, 2005 Posts: 419 Comments: 127355
436. Patrap
5:53 PM CST on January 10, 2007
Sunset at the western Outfall Canal...6
Member Since: July 3, 2005 Posts: 419 Comments: 127355
435. Skyepony (Mod)
11:51 PM GMT on January 10, 2007
NEW YORK (AP) _ It lasted just a few minutes and left barely a trace on the ground, but New York City has now seen its first winter snow _ the latest of any winter in 129 years.
Member Since: Posts: Comments:
434. Skyepony (Mod)
11:50 PM GMT on January 10, 2007
Crazy fire season continues..

Malibu Widlfire Destroys Suzanne Sommers' Home

Member Since: Posts: Comments:
433. drivecde
11:14 PM GMT on January 10, 2007
I was an emergency responder in NO during Katrina, Patrap, I know what you went through and what you are going through NO and Louisana Gov has to get their act together
Member Since: Posts: Comments:
432. weatherboykris
11:10 PM GMT on January 10, 2007
Bitter cold encompasses all of the East next week,even Florida which is kind of unusual as earlier model runs were indicating that the front would stall just to the north of South Florida.
18zGFS
Member Since: December 9, 2006 Posts: 125 Comments: 11346
431. Patrap
4:29 PM CST on January 10, 2007
If anyone ever makes it here look me up.Ill give ya THE tour..LOL.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
430. Patrap
4:27 PM CST on January 10, 2007
I also have a Big Heart.It just that some times..the depression of Living the way we do here now..kinda skews my reaction to some topics.If I come off gruff and tough sometimes..It may be from a day not going so well here.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
428. Patrap
4:26 PM CST on January 10, 2007
Aplogies not neccasary.Im a big guy.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
427. Patrap
4:22 PM CST on January 10, 2007
This venue..has been good for me.It helps me relate my experiences from Katrina and other storms Ive weathered.Hopefully..the things we discuss about that event can enlighten others to be aware of the inherent dangers of a Hurricane.Too many think it can be numbered..catorgorized..measured..Deciphered.At the end of the day..like every day since the storm.Its a bout people.Not the storm..People.Some never see that here.And for them..Im truly saddened.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
425. Patrap
4:21 PM CST on January 10, 2007
Thanks Kris...
Member Since: July 3, 2005 Posts: 419 Comments: 127355
424. weatherboykris
10:19 PM GMT on January 10, 2007
sorry to hear that,Patrap
Member Since: December 9, 2006 Posts: 125 Comments: 11346
422. Patrap
4:15 PM CST on January 10, 2007
Later...
Member Since: July 3, 2005 Posts: 419 Comments: 127355
421. Patrap
4:12 PM CST on January 10, 2007
I asked you once Pat..or Cb.Please dont reference my Katrina Exp[erience.. or that you could have done anything to Prevent it.I buried Family..and spent too much time in the water that youll never Know about.So please..dont refer to the Storm so Litely...thanks.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
418. Patrap
4:00 PM CST on January 10, 2007
Im 12 Feet below sea--level here..LOL
Member Since: July 3, 2005 Posts: 419 Comments: 127355
417. Patrap
4:00 PM CST on January 10, 2007
Sunset Yesterday..too many clouds near Horizion7
Member Since: July 3, 2005 Posts: 419 Comments: 127355
416. Patrap
3:57 PM CST on January 10, 2007
Ill be Here at 5:18pm cst..Sitting on the western Levee I-wall..6
Member Since: July 3, 2005 Posts: 419 Comments: 127355
415. Patrap
3:56 PM CST on January 10, 2007
Lost my Canon in KAtrina..only have Binocular Camera and..Vivitar..
Member Since: July 3, 2005 Posts: 419 Comments: 127355
413. Patrap
3:51 PM CST on January 10, 2007
Those were taken with a Canon AE-1 on tripod 30 sec Exp...
Member Since: July 3, 2005 Posts: 419 Comments: 127355
412. Patrap
3:51 PM CST on January 10, 2007
6
Member Since: July 3, 2005 Posts: 419 Comments: 127355
411. Patrap
3:49 PM CST on January 10, 2007
Have to get Negs of 1000sp Royal Gold..digitized.My scanner dont do them Justice.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
410. Patrap
3:46 PM CST on January 10, 2007
LOL...Hale-Bopp.....Was Much brigther..With the Methane Blue Plume...friend.The 4000$ or so I made of the Pics were worth the Mosquitos that Night...27 outta 36 Usable prints..8x10s and 20 x 30s.SOld fast.Will have Blog in April on that Event..10yr anniversay.
Member Since: July 3, 2005 Posts: 419 Comments: 127355
406. jeffB
9:44 PM GMT on January 10, 2007
Sorry, but Hale-Bopp was NOT brighter:

http://cfa-www.harvard.edu/icq/brightest.html

It APPEARED brighter, because it was visible against a darker sky.
Member Since: Posts: Comments:
405. Patrap
3:43 PM CST on January 10, 2007
7
Member Since: July 3, 2005 Posts: 419 Comments: 127355
403. Patrap
3:40 PM CST on January 10, 2007
Wrong again..It was discovered Last year..your way out your scope again..Tunnel dat..LOL
Member Since: July 3, 2005 Posts: 419 Comments: 127355
402. Patrap
3:39 PM CST on January 10, 2007
Comet McNaught Pic from Jan 5..plus details.Link
Member Since: July 3, 2005 Posts: 419 Comments: 127355
400. Patrap
3:37 PM CST on January 10, 2007
HAle Bopp was much Brighter Than McNaught..by many Magnitudes..wrong again..7
Member Since: July 3, 2005 Posts: 419 Comments: 127355

Viewing: 449 - 399

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.