| Above: The deadliest weather-related disaster of May was in Sri Lanka, where the arrival of the southwest monsoon—combined with moisture from what would eventually develop into Cyclone Mora—led to significant rainfall from May 25 to 31. At least 213 people were killed, with another 77 people listed as missing and presumed dead. Damage from the disaster was estimated at $1.97 billion. In this image, we see Sri Lankan Army personnel distribute food to flood victims in Molkawa in the district of Kalutara on May 30, 2017. Image credit: Lakruwan Wanniarachchi/AFP/Getty Images. |
May 2017 was the planet's third warmest May since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Monday. NASA rated May 2017 as the second warmest May on record. The only warmer May in NASA records was just last year, in 2016, while the month came in just behind May 2016 and May 2015 in the NOAA data. Minor differences can occur between the NASA and NOAA rankings because of their different techniques for analyzing data-sparse regions such as the Arctic.
Global ocean temperatures last month were the third warmest on record for any May, according to NOAA, and global land temperatures were the seventh warmest on record. Global satellite-measured temperatures for the lowest 8 km of the atmosphere were the third warmest for any May in the 39-year record, according to the University of Alabama Huntsville (UAH).
Second-warmest year on record thus far
May 2017 ranked as the eighteenth warmest month (expressed as the departure of temperature from average) of any month in the global historical record in the NASA database. The extreme warmth of January 2017 (thirteenth warmest month of any month in NASA’s database), February 2017 (sixth warmest), March 2017 (fifth warmest) and now April and May (tied for eighteenth warmest) gives 2017 a good chance of becoming Earth’s second warmest year on record, behind 2016. This is especially remarkable given the presence of weak La Niña conditions in late 2016 and early 2017. Global temperatures tend to be warmer during El Niño than during La Niña, as the ocean releases more heat to the atmosphere during El Niño events.
For the year-to-date period of January - May 2017, the NOAA record shows that Earth's temperature was 0.92°C (1.66°F) above the 20th-century average of 13.1°C (55.5°F). This is the second highest such period since records began in 1880, behind 2016 by 0.17°C (0.31°F).
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| Figure 1. Departure of temperature from average for May 2017, the second warmest May for the globe since record keeping began in 1880. Warmer-than-average temperatures were widespread across most of the planet; cooler-than-average readings occurred across the central United States, southeast Canada, eastern Europe, far western Australia, and much of western and central Russia. Image credit: National Centers for Environmental Information (NCEI). |
One billion-dollar weather disaster in May 2017
One billion-dollar weather disaster hit the Earth last month, according to the May 2017 Catastrophe Report from insurance broker Aon Benfield: a severe weather/tornado outbreak in the U.S. Rocky Mountain/Great Plains region. By the end of May, Earth had registered ten billion-dollar weather events for 2017, which is a typical number for this point in the year. The year that ended with the most billion-dollar weather disasters in records going back to 1990 was 2013, with 41, and that year had thirteen billion-dollar disasters by the end of May. Last year, there were already twenty billion-dollar weather disasters by the end of May (that year ended up with 31 such disasters). Here are this year’s billion-dollar weather disasters through the end of May:
Flooding, Peru, 1/1 – 4/1, $3.1 billion, 120 killed
Severe Weather, Rockies, Plains, U.S., 5/8 – 5/11, $2.5 billion, 0 killed
Severe Weather, Midwest, Plains, Southeast U.S., 3/6 – 3/10, $2.1 billion, 0 killed
Severe Weather, Midwest, Plains, Southeast MS Valley U.S., 4/28 – 5/01, $2.0 billion, 20 killed
Tropical Cyclone Debbie, 3/27 – 4/5, $2.0 billion, 14 killed
Drought, Somalia, Ethiopia, Kenya, 1/1 – 3/31, $1.9 billion, 136+ killed
Severe Weather, South U.S., 2/27 - 3/2, $1.9 billion, 4 killed
Severe Weather, Plains, Southeast, Midwest U.S., 3/26 – 3/28, $1.8 billion, 0 killed
Severe Weather, South U.S., 1/18 - 1/23, $1.3 billion, 21 killed
Winter Weather, Plains, Southeast, Midwest, Northeast U.S., 3/13 - 3/15, $1.0 billion, 11 killed
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| Billion-Dollar Disaster 1. A multi-day severe weather event on May 8 – 11 brought major hailstorms and extensive damage across parts of Colorado, New Mexico, Texas and Oklahoma. Damage was particularly heavy in the greater Denver, CO metro region, as up to baseball-sized hail hit the western suburbs. Total damage was estimated at $2.5 billion. Above: Patrick Clark inspects his damaged car after a strong spring storm moved through the metropolitan Denver area, creating rivers of hail, on Monday afternoon, May 8, 2017. Image credit: AP Photo/P. Solomon Banda. |
No El Niño or La Niña conditions expected through fall
In its June 8 monthly advisory, NOAA’s Climate Prediction Center (CPC) stated that neither El Niño nor La Niña conditions were present in the Eastern Pacific (ENSO-neutral conditions existed), and these neutral conditions were expected to persist through the fall (50 – 55% chance.) Sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) were about 0.5°C above average over the past week; SSTs of 0.5°C or more above average in this region are required to be classified as weak El Niño conditions, with the 3-month average SSTs holding at these levels for five consecutive months (with an accompanying El Niño-like atmospheric response). A modest surge of enhanced east-to-west blowing trade winds is predicted for the west-central Pacific over the next two weeks, and these stronger-than-average trade winds will interfere with any progression towards El Niño.
NOAA forecasters gave a 35 - 50% chance of an El Niño event occurring this year—a slight downgrade from their previous month’s forecast, which gave a 45% chance. El Niño conditions tend to suppress Atlantic hurricane activity by bringing strong upper-level winds to the tropical Atlantic, creating high wind shear that tears storms apart. A reduction in the odds of El Niño boosts the odds of an active Atlantic hurricane season. In their latest June 13 forecast, The Weather Company upped their predicted numbers for the Atlantic hurricane season to 15 named storms, 8 hurricanes and 3 intense hurricanes; their previous May forecast, when a fall El Niño event was looking more likely, called for 14 named storms, 7 hurricanes, and 3 intense hurricanes.
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| Figure 2. Sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) have been hovering at about 0.4°C above average for most of May, just below the threshold 0.5°C above average threshold for weak El Niño conditions. Image credit: Levi Cowan, tropicaltidbits.com. |
Arctic sea ice extent fourth lowest on record for May
Arctic sea ice extent during May 2017 had the fourth lowest extent in the 38-year satellite record, according to the National Snow and Ice Data Center (NSIDC). This broke a streak of seven consecutive months when the Arctic sea ice had set record-low monthly extent records, from October 2016 – April 2017. However, as we reported on June 9, the total volume of the ice was at record low levels for May in 2017, and the sea ice is vulnerable to a record summer melt season if weather conditions bring plenty of sunshine and high pressure to the Arctic over the next few months. That won’t be the case through the end of June, though, as the GFS model is predicting that low pressure and cloudy skies will dominate the Arctic.
Antarctic sea ice no longer setting record lows--barely
Sea ice surrounding Antarctica was at unprecedented lows in recent months, setting an all-time monthly minimum extent record each month during the five-month period November 2016 – March 2017. However, monthly Antarctic sea ice extent in both April and May of 2017 was the second lowest on record for their respective months, just behind the record lows set in 1980.
Notable global heat and cold marks set for May 2017
Hottest temperature in the Northern Hemisphere: 53.5°C (128.3°F) at Turbat, Pakistan, 28 May
Coldest temperature in the Northern Hemisphere: -53.4°C (-36.6°F) at Summit, Greenland, 13 May
Hottest temperature in the Southern Hemisphere: 39.4°C (102.9°F) at Picos, Brazil, 16 May
Coldest temperature in the Southern Hemisphere: -78.5°C (-109.3°F) at Dome Fuji, Antarctica, 15 May
(Courtesy of Maximiliano Herrera.)
Major weather stations that set (not tied) new all-time heat or cold records in May 2017
Turbat (Pakistan), max. 53.5°C, 28 May*
Panjgur (Pakistan), max. 47.0°C, 29 May
Notes:
*Ties the national record of highest temperature of Pakistan for any month, and the world record of highest temperature in May.
On 30 May, Oman tied its national record of highest temperature ever with 50.8°C at Qurayyat. On 31 May, the national record was tied again, this time at Joba. Those all-time records, along with many other all-time records of other stations in Oman, Iran and Pakistan are not listed above because their series are too short.
(Courtesy of Maximiliano Herrera.)
Two all-time national heat records tied in May 2017
As noted above, two nations (Pakistan and Oman) tied their all-time records for hottest temperature in recorded history in May 2017. As of June 17, seven nations set or tied all-time national heat records in 2017, and two set or tied all-time cold records. Most nations do not maintain official databases of extreme temperature records, so the national temperature records reported here are in many cases not official. I use as my source for international weather records researcher Maximiliano Herrera, one of the world's top climatologists, who maintains a comprehensive list of extreme temperature records for every nation in the world on his website. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records.
All-time national heat records set or tied in 2017:
United Arab Emirates: 124.7°F (51.5°C) at Mezaira, 16 June
Oman: 123.4°F (50.8°C) at Qurayyat on 30 May and at Joba on 31 May (tie)
Pakistan: 128.3°F (53.5°C) at Turbat on 28 May (tie)
Guinea: 113°F (45.0°C) at Koundara, 29 March (tie)
Ghana: 110.8°F (43.8°C) at Navrongo, 26 March
Chile: 113°F (45.0°C) at Cauquenes, 26 January
Cocos Islands (Australia): 91.2°F (32.9°C) at Cocos Island Airport, 23 February
All-time national cold records set in 2017:
United Arab Emirates: 22.3°F (-5.4°C) at Jabel Jais, 3 February
Qatar: 34.7°F (1.5°C) at Abu Samra, 5 February
Bob Henson contributed to this post.
