Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 12:19 PM GMT on July 23, 2012
June 2012 was the globe's 4th warmest June on record, according to the National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC). NASA rated May 2012 the 3rd warmest on record. June 2012 global land temperatures were the warmest on record; this makes three months in a row--April, May, and June--in which record-high monthly land temperature records were set. Global ocean temperatures were the 10th warmest on record. June 2012 was the 328th consecutive month with global temperatures warmer than the 20th century average; the last time global temperatures were below average was February 1985. We've now had three consecutive top-five warmest months on record; April 2012 was the 5th warmest April on record, and May 2012 was the 2nd warmest May on record. The increase in global temperatures relative to average, compared to March 2012 (16th warmest March on record) is due, in part, to warming waters in the Eastern Pacific, where a La Niña event ended in April, and borderline El Niño conditions now exist. Global satellite-measured temperatures in June for the lowest 8 km of the atmosphere were 4th or 3rd warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). Northern Hemisphere snow cover extent during June 2012 was the smallest in the 46-year period of record. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of June in his June 2012 Global Weather Extremes Summary. Notably:
- The U.K. suffered through its wettest June since at least 1910, and coolest such since 1991.
- The monsoon season has been especially devastating so far along the banks of the Brahmaputra River in northeast India and Bangladesh. Over 2000 villages have been flooded and at least 190 deaths reported so far. Almost 20 million people in all have been displaced.
- The Korean Peninsula continued to endure its worst drought in at least 105 years.
Figure 1. Departure of temperature from average for June 2012. In the Northern Hemisphere, most areas experienced much higher-than-average monthly temperatures, including most of North America and Eurasia, and northern Africa. Only northern and western Europe, and the northwestern United States were notably cooler than average. Image credit: National Climatic Data Center (NCDC) .
Arctic sea ice has greatest June loss on record
Arctic sea ice saw its greatest-ever decrease during the month of June, and ice extent averaged over the entire month was the 2nd lowest for June in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). The last three Junes (2010 - 2012) have had the three smallest ice extents for the month, with June 2012 being the 21st consecutive June and the 133rd consecutive month with below-average Arctic sea ice extent. During much of June 2012 and extending into the first half of July, the Arctic Dipole pattern set up. This atmospheric circulation pattern features a surface high pressure system in the Arctic north of Alaska, and a low pressure system on the Eurasian side of the Arctic. This results in winds blowing from south to north over Siberia, pushing warm air into the central Arctic Ocean. The Arctic Dipole pattern occurred in all summer months of 2007 and helped support the record 2007 summer reduction in sea ice extent. The Arctic Dipole pattern has broken down over the past few days, and is expected to be absent through early August. This should slow Arctic sea ice loss, and ice extent may no longer be at record low levels by the first week of August.
Figure 2. Arctic sea ice area in 2012 as of July 22 (yellow line) compared to all the other years since satellite observations began in 1979. Ice area in 2012 during most of June and July has been the lowest on record. The previous record low years were 2007 and 2011. Note that sea ice area (as shown here) and sea ice extent (as measured by the National Snow and Ice Data Center) are not the same thing, but one can use either to quantify sea ice, and both show very similar behavior. Image credit: University of Illinois Cryosphere Today.
Three new billion-dollar weather disasters in June
The globe experienced three new billion-dollar weather disasters in June, bringing the total for the year to nine, said insurance broker Aon Benfield in their June Catastrophe Report. The most expensive disaster in June occurred in China, where heavy rains between the between June 20 - 29 affected northern, central, eastern and southern sections of the country. The rains left at least 50 people dead in 17 separate provinces, and caused damage estimated at CNY17.4 billion (USD2.73 billion). The U.S. suffered two billion-dollar severe weather events in June, bringing the total number of such events to six for the year. The record for most billion-dollar disasters in a year in the U.S. is fourteen (according to NOAA/NCDC) or seventeen (according to Aon Benfield.) The most costly event in June 2012 came across portions of Texas and New Mexico, where severe thunderstorms pelted areas (including the Dallas-Fort Worth metropolitan region) with golf ball and baseball-sized hail. The Insurance Council of Texas said that more than 100,000 claims were filed and total insured losses in the state would exceed $1 billion, with total losses near $1.75 billion. A separate hail event in Colorado and Wyoming caused more than $700 million in insured losses, and $1.25 billion in total losses.
Figure 3. Weather disasters costing at least half a billion dollars so far in 2012, according to insurance broker Aon Benfield in their June Catastrophe Report.
Heaviest rains in 60 years deluge Beijing, killing 37
China's latest billion-dollar weather disaster is a torrential rainstorm that hit Beijing Saturday night, dumping the the heaviest rains the city has seen in 60 years, according to Associated Press. The resulting flooding killed 37 people and did $1.6 billion in damage.
Figure 4. A Chinese man uses a signboard to signal motorists driving through flooded street following a heavy rain in Beijing Saturday, July 21, 2012. China's government says the heaviest rains to hit Beijing in six decades. The torrential downpour Saturday night left low-lying streets flooded and knocked down trees. (AP Photo)
Quiet in the Atlantic
There are no threat areas to discuss in the Atlantic, and none of the reliable computer models are developing a tropical cyclone over the next seven days.
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