U.S. experiences warmest 12-month period on record--again

By: Dr. Jeff Masters , 9:04 PM GMT on July 09, 2012

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Thanks in part to the historic heat wave that demolished thousands of high temperature records at the end of June, temperatures in the contiguous U.S. were the warmest on record over the past twelve months and for the year-to-date period of January - June, said NOAA's National Climatic Data Center (NCDC) on Monday. June 2012 was the 14th warmest June on record, so was not as extreme overall as March 2012 (first warmest March on record), April (third warmest April), or May (second warmest May.) However, temperatures were warm enough in June to set a new U.S. record for hottest 12-month period for the third straight month, narrowly eclipsing the record set just the previous month. The past thirteen months have featured America's 2nd warmest summer (in 2011), 4th warmest winter, and warmest spring on record. Twenty-six states were record warm for the 12-month period, and an additional sixteen states were top-ten warm. The year-to-date period of January - June was the warmest on record by an unusually large margin--1.2°F.


Figure 1. This time series shows the five warmest years that the contiguous U.S. has experienced, and how the year-to-date temperature evolved each month throughout those years. The time series also shows the 2012 year-to-date temperature through June, which was the warmest first half of any year on record for the lower 48. The 2012 data are still preliminary. Image credit: NOAA/NCDC.


Figure 2. Four of the top-ten warmest 12-month periods in the contiguous U.S. since 1895 have occurred since April 2011. Image credit: NOAA/NCDC.

Most extreme January - June period on record
NOAA's U.S. Climate Extremes Index (CEI), which tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought, was 44% during the year-to-date January - June period. This is the highest value since CEI record-keeping began in 1910, and more than twice the average value. Remarkably, 83% of the contiguous U.S. had maximum temperatures that were in the warmest 10% historically during the first six months of 2012, and 70% of the U.S. of the U.S. had warm minimum temperatures in the top 10%. The percentage area of the U.S. experiencing top-10% drought conditions was 20%, which was the 14th greatest since 1910. Extremes in 1-day spring heavy precipitation events were near average.


Figure 3. NOAA's U.S. Climate Extremes Index (CEI) for January - June shows that 2012 has had the most extreme first six months of the year on record, with 44% of the contiguous U.S. experiencing top-10% extreme weather.

Tuesday Webinar on the future of extreme weather impacts on business
I'm presenting a 12-minute Webinar talk on the future of weather-related disasters at 2 pm EDT Tuesday July 10. If you want to register (it's free) and listen in, visit the propertycasualty360.com web site. The title of the webinar is, "The Year-Round CAT Season: Is Your Business Prepared for Increasingly Frequent Severe Weather?"

"New McCarthyism" targets climate scientists
Bill Blakemore with ABC News has an interesting five-part interview with climate scientist Dr. Michael Mann, where Dr. Mann explains how a "New McCarthyism" is targeting climate scientists. I reviewed Dr. Mann's excellent book, "The Hockey Stick and the Climate Wars", earlier this year.

A 1 in 1.6 million event?
I originally wrote in this post that "Each of the 13 months from June 2011 through June 2012 ranked among the warmest third of their historical distribution for the first time in the 1895 - present record. According to NCDC, the odds of this occurring randomly during any particular month are 1 in 1,594,323. Thus, we should only see one more 13-month period so warm between now and 124,652 AD--assuming the climate is staying the same as it did during the past 118 years."

It has been pointed out to me that the calculation of a 1 in 1.6 million chance of occurrence (based on taking the number 1/3 and raising it to the 13th power) would be true only if each month had no correlation to the next month. Since weather patterns tend to persist, they are not truly random from one month to the next. Thus, the odds of such an event occurring are greater than 1 in 1.6 million--but are still very rare. I appreciate hearing from those of you who wrote to point out a correction was needed.

Jeff Masters

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Quoting hurricanejunky:
Nice flare-ups of convection off the TX coast and near the FL Keys...



but NO circles...
Hey, hj... just saw that was u... how's it going?
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Yes, will be interesting with wave/trough coming in thru FL straits into Gulf with existing trough over E TX-W LA. One big soup bowl coming together for rain and convection. A monsoon if you will.
Member Since: July 14, 2008 Posts: 2 Comments: 9686
Quoting ernesto2012:



its all due to and ULL...


Out in the GOM? I also see a swirl and some convection in the Bahamas but I'm assuming that's also a ULL...
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Quoting MississippiWx:
I'm in Perdido Beach, FL in a beautiful condo. My family and I have been watching waterspout after waterspout drop out of the clouds this morning, one was large and all the way to the ocean. If any of you plan to hit the ocean in a boat or hit the beaches this afternoon, pay attention to what's on the Gulf.
..thanks for the warning
Member Since: August 6, 2011 Posts: 4 Comments: 42085
We got SE winds at about 12 kts here right now, partly cloudy skies... not too hot at all. So far so good on the holiday beach bash potential.

Ya'll know what happened when I disappear offa here... lol

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Ahh...you know it's July when everybody comes on saying the season is a bust. Happens every year.
Member Since: July 6, 2010 Posts: 113 Comments: 32818
Quoting TropicalAnalystwx13:

Yes.

I keep this page (link) updated if anybody wants to track the individual ACE for each storm at each advisory.
Member Since: July 6, 2010 Posts: 113 Comments: 32818
Quoting trHUrrIXC5MMX:


no, no, I mean the ACE value for 130 mph winds. since 135 mph was 1.3225, would they use that one?

Yes.
Member Since: July 6, 2010 Posts: 113 Comments: 32818
Good Day to All from America's Left Coast!
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Quoting Neapolitan:
Convenient? Really? To paraphrase a great literary line: I find it decidedly inconvenient that the current observed warming is due in large part (if not entirely) to our emissions of CO2.


CO2. Us.

Methane. We drill holes in the Earth and let it out.

Carbon black/soot. Humans burn stuff and make soot.

Nitrous oxide. Us.

Ozone. Us.

Water vapor. We've heated up the planet, heat evaporates water. Us.




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I'm in Perdido Beach, FL in a beautiful condo. My family and I have been watching waterspout after waterspout drop out of the clouds this morning, one was large and all the way to the ocean. If any of you plan to hit the ocean in a boat or hit the beaches this afternoon, pay attention to what's on the Gulf.
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Wow, I just realized how much of the United States is experiencing drought conditions.



That's quite a bit.
Member Since: August 2, 2006 Posts: 47 Comments: 11709
I got my link to the Webinar in my E-mail this morning.
Member Since: July 3, 2005 Posts: 428 Comments: 129841
689. txjac
Quoting Patrap:
Tuesday Webinar on the future of extreme weather impacts on business
I'm presenting a 12-minute Webinar talk on the future of weather-related disasters at 2 pm EDT Tuesday July 10. If you want to register (it's free) and listen in, visit the propertycasualty360.com web site. The title of the webinar is, "The Year-Round CAT Season: Is Your Business Prepared for Increasingly Frequent Severe Weather?"


Actually thats a quite interesting subject. Our company is considering moving our data center to Arizona for this exact reason.
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Quoting bubbalady:
Yeah, I've been watching that little thing down in SW FL, too.

But the big question on my mind is why no one is discussing the recent (as in, beginning in the Fall of last year) increase in solar flares and their connection to the recent heatwave? IMHO the flares are likely the culprit.


What's the science you're using to connect solar flares and the recent heat wave?
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Nice flare-ups of convection off the TX coast and near the FL Keys...



but NO circles...
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Solar Flares DO NOT have ANY affect on the Temp on Earth.



Global surface temperature (top, blue) and the Sun's energy received at the top of Earth's atmosphere (red, bottom). Solar energy has been measured by satellites since 1978.

The amount of solar energy received at the top of our atmosphere has followed its natural 11-year cycle of small ups and downs, but with no net increase. Over the same period, global temperature has risen markedly. This indicates that it is extremely unlikely that solar influence has been a significant driver of global temperature change over several decades.
Member Since: July 3, 2005 Posts: 428 Comments: 129841
Quoting Patrap:
"Blob" is such a un-met term. I never ever use it.

Its part of the Duh-ing down of America.
Hey! I kinda like "blob"... it's an all-purpose, generic, non-met kinda word... quite useful in instances where you mean something that does not quite meet AOI standards...

However...

YMMV...
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Tuesday Webinar on the future of extreme weather impacts on business
I'm presenting a 12-minute Webinar talk on the future of weather-related disasters at 2 pm EDT Tuesday July 10. If you want to register (it's free) and listen in, visit the propertycasualty360.com web site. The title of the webinar is, "The Year-Round CAT Season: Is Your Business Prepared for Increasingly Frequent Severe Weather?"
Member Since: July 3, 2005 Posts: 428 Comments: 129841


Member Since: July 3, 2005 Posts: 428 Comments: 129841


Posted: Tuesday, 10 July 2012 6:15AM

New Orleans tops tourism list for 3rd year
Member Since: July 3, 2005 Posts: 428 Comments: 129841
Quoting ILwthrfan:


I feel ya, its getting almost as bad here now too. I have dumped just under 0.25 inches in the last 8 weeks. Crops are gone.
It is tough when you go thru 8 weeks without rain and temps around 100, sorry for all the farmers, hope you get relief soon. I was raised on a farm in North Texas so I feel your pain.
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Quoting TropicalAnalystwx13:

7.06 units.


no, no, I mean the ACE value for 130 mph winds. since 135 mph was 1.3225, would they use that one?
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I wonder if 1934 could be considered an analog year? While I know events in the CONUS don't automatically correlate to tropical activity in the ATL, I'm thinking a strong high over the midwest with another in the mid-Atlantic [and likely el Nino conditions, though I'm not sure how one would prove that] may have had a similar impact on TC formation locations and track....
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Yeah, I've been watching that little thing down in SW FL, too.

But the big question on my mind is why no one is discussing the recent (as in, beginning in the Fall of last year) increase in solar flares and their connection to the recent heatwave? IMHO the flares are likely the culprit.
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Quoting akailm:
it's really not an issue that warming has occured.. to place the blame on co2 is not a reality.it's a convient theory.
Convenient? Really? To paraphrase a great literary line: I find it decidedly inconvenient that the current observed warming is due in large part (if not entirely) to our emissions of CO2.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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