US: Warmest Year On Record

As many probably know by now, 2012 was the warmest year on record for the contiguous United States.  In fact last year obliterated to previous record.  The record was eclipsed by a full one degree Fahrenheit.  This was an astounding result and is outside any normal experience.  The graphic below illustrates the comparison with the five warmest years on record.

A comparison of the average temperature for the contiguous U.S. with the warmest years on record.  Image Credit: Climate Central.

Every state saw warmer than normal temperatures for the year, however the amount of heat was not uniform.  Record heat was reported in the Southwest, Central U.S., and the Northeast.  It was quite hot in the Southeast, but much of the area escaped the hottest temperatures.  Many of the all-time record high temperatures set during the Dust Bowl era fell in the central U.S. this past summer.

A look at the distribution of heat across the U.S. for 2012.  Image Credit: Climate Central.

Winter Outlook for 2012-13

The Climate Prediction Center released its early outlook for the upcoming winter this morning.  Much of the western U.S. will see warmer than normal temperatures while cooler than normal temperatures are expected for the Florida peninsula.  Equal chances of above or below normal temperatures are forecast for much of the East.

Much of the West will be dry particularly in the Pacific Northwest.  The Central Gulf region is expected to be wetter than normal.  This may help ease the drought in Georgia and South Carolina.

Click on either graphic for a larger version or go here for the temperature map and here for the precipitation map.  Image Credit: NOAA\CPC.

How Cold Does It Have To Be?

As we close in on the last quarter of the year (and the end of baseball’s regular season), 2012 is on track to be the country's hottest year ever recorded. But as Yogi Berra says, “It ain't over 'til it's over.”

So how cold would it need to be for the rest of the year to miss the record?

Click on the image to see the high resolution version.  Image Credit: Climate Central.

Pretty darn cold. As you can see in the graphic above, based on temperature data from NOAA’s NCDC, if we have normal fall and winter temperatures every month for the rest of the year, we will clearly break the record (yellow line). If it stays warmer than average, we will break the record by even more (orange line). In order to miss breaking the record as the hottest year ever recorded in the United States, the months of September through December would each need to be among the coolest third of those months on record (green line).

Extreme Heat: The Odds Are Increasing

A number of people have been asking me during this exceptional heat wave if it was being caused by global warming.  My response has been that “global warming doesn’t cause the heat wave; it causes the heat wave to be hotter.”  Privately I had been telling people that we would likely break the all-time record high temperature in Columbia in the next 20 years.  That was two years before it happened.

The fact that so many record high temperatures are being broken is no surprise.  A 2009 study published in the Geophysical Research Letters showed that daily record-high temperatures were outpacing daily record lows by a 2:1 ratio in the first decade of this century.  If the climate were not warming the ratio would be 1:1.  The study showed that on a business as usual scenario the ratio would expand to 20:1 by 2050 and 50:1 by 2100.

The ratio of high to low temperature records from the 2009 study listed above.  Click on the graphic for a high-definition view of the graph.  Image Credit: Climate Central.

However, this year the ratio has expanded to 7:1 for the nation since the beginning of the year.  Almost 8,000 high temperature records have been set in just the past month.  Some of these records recently have been all-time record highs breaking records from the Dust Bowl Era.  Keep in mind that there have been two record heat events already this year.  The first was the record warm spell in March and now the exceptional heat wave this past month.

The ratio of high to low temperature records for June and the first half of 2012.  Click on the graphic for a larger view.  Image Credit: Climate Central.

2011 Global Temperatures and A Look Ahead

There are three organizations that regularly analyze the global temperature record on an annual basis.  The three international global temperature data sets are from the Met Office and University of East Anglia (HadCRUT3), NOAA National Climatic Data Center (NOAA NCDC) and NASA Goddard Institute of Space Studies (NASA GISS).  Final figures from HadCRUT3 will not be available until March, 2012.  While the other two are also preliminary, the additional data yet to come will not likely change the findings.

This is what the three data sets looked like together as of October, 2011:

Image credit: UK Met Office.

NASA GISS recently released its figure for all of 2011.  The year was the ninth warmest on record according to its analysis.  Meanwhile, HadCRUT3 and NOAA NCDC listed this past year as the eleventh warmest on record.

Global temperature anomalies 1880-2011.  Image credit: NASA GISS