Tuesday, July 24, 2012

The Drought Eases In South Carolina

It takes time to move into a drought.  Likewise, it takes time to move out of a drought.  The recent rains have definitely eased the pain for South Carolina.  According to the latest drought monitor from the USDA only 22% of the state is in a severe drought or worse compared to 32% the previous week.  Much of the Pee Dee region is out of the drought completely.

Click on image for a larger view.  Image Credit: USDA.

The first four months of the year were a continuation of the drought that started in January 2010.  Only four months out of the past 28 months had been wet by the end of April.  The total rainfall by then for 2012 was 8.71 inches at the Columbia Metropolitan Airport or just over 2 inches per month.

Friday, July 13, 2012

Climate Change Attributions

Extreme Heat: The Odds Are Increasing, was published just before the American Meteorological Society (AMS) released their annual climate report this past week. 

The 2011 State of the Climate report is peer-reviewed and published annually as a special supplement to the Bulletin of the American Meteorological Society. The report is part of a suite of climate services NOAA provides government, business and community leaders so they can make informed decisions. It was edited by Jessica Blunden, Ph.D., and Deke Arndt of NOAA’s National Climatic Data Center. The full report can be viewed online. The report highlights are available online.

The map above shows where in the United States June 2012 temperatures were different from the 1981–2010 average. Shades of red indicate temperatures up to 8° Fahrenheit warmer than average, and shades of blue indicate temperatures up to 5° Fahrenheit cooler than average—the darker the color, the larger the temperature difference.  Image Credit: NOAA Climate.

Additionally, for the first time a complementary article was published by the AMS examining the linkages between climate change and extreme events of 2011. The paper looked at six global extreme weather and climate events from last year.

Saturday, July 7, 2012

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.

Sunday, July 1, 2012

An Unprecedented Heat Wave

Image Credit: WLTX-TV.
Columbia, South Carolina markets itself as being “Famously Hot” and this weekend it lived up to that billing in ways never imagined.  The heat wave that hit the area was unprecedented in speed and intensity.  Fortunately everyone knew it was coming, but it was still under forecast.

It took only one day to be in the heat wave.  The high temperature on Wednesday was 89 F, but it reached 100 F on Thursday, the start of the heat wave.  However, the peak of the heat wave intensity was on Friday when the temperature soared to an all-time record high of 109 F at the Columbia Metropolitan Airport and 110 F at Hamilton-Owens Field, just south of downtown Columbia.  The temperature at the airport had never been above 107 F.

High temperatures for Friday, June 29, 2012, in South Carolina.  Image Credit: WLTX-TV.

In addition, it was not until Saturday when the co-op reports came into the National Weather Service that it was discovered that the all-time record high for the state of South Carolina was broken.  The previous all-time high was 111 F set at Calhoun Falls and Blackville in 1925 and in Camden in 1954.  It reached 113 F in Johnston and the campus of the University of South Carolina in Columbia, Friday afternoon.  This still has to be confirmed by the state climatology office, but it is very likely that one or both will stand as the new all-time record high for the state of South Carolina.