Above: The deadliest weather disaster of March 2018 was Tropical Cyclone Eliakim, which killed 21 people in Madagascar after making landfall as a tropical storm with 65 mph winds on March 16. This natural-color image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite on March 15, 2018. Image credit: NASA.
March 2018 was the planet's fifth warmest March since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Wednesday. NASA rated March 2018 as the sixth warmest March on record, with the only warmer March months being 2016, 2017, 2010, 2002, and 2015. The difference in rankings between NASA and NOAA is mostly due to how they handle data-sparse regions such as the Arctic, where few surface weather stations exist. The rankings for March were cooler than we've seen in recent years thanks to the presence of colder weather than average over much of Europe, plus the presence of cool ocean temperatures over the Eastern Pacific from a weak La Niña event.
Global ocean temperatures during March 2018 were the fifth warmest on record, and global land temperatures were the seventh warmest on record. Global satellite-measured temperatures in March 2018 for the lowest 8 km of the atmosphere were the sixth or ninth warmest in the 40-year record, according to the University of Alabama Huntsville (UAH) and RSS, respectively.
|Figure 1. Departure of temperature from average for March 2018, the 9th-warmest March for the globe since record keeping began in 1880. Record warmth was observed across parts of eastern Africa, the Middle East, and southern Asia, which corresponds with the locations that had the most notable warm temperature departures from average (+3.0°C [+5.4°F] or higher) during the month. No land or ocean areas experienced record cold temperatures during March 2018. Image credit: National Centers for Environmental Information (NCEI).|
Three billion-dollar weather disasters in March 2018
Three billion-dollar weather-related disasters hit the Earth last month, according to the March 2018 Catastrophe Report from insurance broker Aon Benfield: a drought in South America ($3.9 billion), Winter Storm Riley in the Eastern U.S. ($2 billion), and a severe weather outbreak in the U.S. ($1.35 billion). The deadliest weather event of March was Tropical Cyclone Eliakim, which killed 21 people in Madagascar on March 17 – 18. Here is the tally of billion-dollar weather disasters so far in 2018:
1) Drought, Argentina and Uruguay, 1/1 – 3/31, $3.9 billion, 0 killed
2) Winter Storm Friederike, Western & Central Europe, 1/18, $2 billion, 13 killed
3) Winter Storm Riley, Eastern U.S., 3/1 – 3/3, $2 billion, 9 killed
4) Severe Weather, Plains, Southeast, Northeast U.S., 3/18 – 3/21, $1.35 billion, 0 killed
5) Winter Storm Eleanor & Carmen, Western & Central Europe, 1/1 – 1/4, $1.25 billion, 7 killed
6) Winter Storm Grayson, Central & Eastern U.S., 1/3 – 1/5, $1.1 billion, 22 killed
7) Winter Weather, China, 1/24 – 1/29, $1.1 billion, 2 killed
March Billion-Dollar Disaster 1. A severe lack of rainfall over southern South America during the summer of 2017 - 2018 has led to the worst drought in decades over portions of Argentina and Uruguay. Total losses are near $3.9 billion, making the drought the most expensive weather-related disaster on the planet so far in 2018--and the most expensive disaster in the history of both Argentina and Uruguay. Hardest-hit was Argentina, where the Buenos Aires Grain Exchange predicted that the drought would likely cause an economic loss of $3.4 billion. Above: Soil moisture maps produced with data collected on April 3, 2017 (left), and April 6, 2018 (right), by NASA’s Soil Moisture Active Passive (SMAP) satellite. SMAP carries a radiometer that measures soil moisture in the top 5 centimeters (2 inches) of the ground. Dark green and blue areas are progressively wetter. Pronounced drying in 2018 compared to 2017 is apparent. Image credit: NASA Earth Observatory.
|March Billion-Dollar Disaster 2. A powerful nor’easter--Winter Storm Riley--brought hurricane-force wind gusts, heavy snowfall, torrential rain, and coastal flooding to much of the Northeast and Mid-Atlantic U.S. coast from March 1 - 3. At least nine people were killed, and states of emergency were declared in Massachusetts, New York, Virginia, and Maryland, where the storm caused widespread wind and storm surge damage. Power outages hit 2.4 million customers as winds gusted up to 93 mph. Total damage, including business interruption, was estimated at $2 billion. Above: a row of homes in Scituate, Massachusetts, is surrounded by high-tide water at midday on Saturday, March 4, 2018. On March 3, Winter Storm Riley brought the third highest storm tide on record to Boston. Image credit: Ralph Karl Swenson, Amateur Radio SKYWARN Spotter (N1YHS), via NWS Taunton Skywarn.|
March Billion-Dollar Disaster 3. Large hail and damaging straight-line winds impacted the central and southern U.S. March 18 - 21. Hardest-hit were Texas, Florida, Alabama, Georgia, and Tennessee. Most damage reports were due to shattered windows, dented roofs, and downed trees. Following the severe weather outbreak, a coastal Nor’easter brought heavy snow to the Mid-Atlantic and Northeast, leading to widespread transit and business disruption. Total damage was estimated at $1.35 billion. Above: A destroyed shed on March 21, 2018 in Scituate, Massachusetts after the fourth nor'easter in three weeks hit. (Photo by Scott Eisen/Getty Images).
La Niña weakens, and is expected to dissipate by May
La Niña conditions remained but weakened over the equatorial Pacific during the past month, said NOAA’s Climate Prediction Center (CPC) in its April 12 monthly advisory. NOAA predicted that the current weak La Niña event that began in August 2017 is near its end, with a 55% chance that it will transition to a neutral state by May (these are the same odds that they gave in their February outlook). The Australian Bureau of Meteorology declared La Niña officially over in the March 13 installment of its biweekly report, and classifies the current conditions as neutral. The bureau uses a more stringent threshold than NOAA for defining La Niña: sea-surface temperatures in the Niño3.4 region of the tropical Pacific must be at least 0.8°C below average, vs. the NOAA benchmark of 0.5°C below average.
Over the past week, sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) were about 0.5°C below average, which are barely in the 0.5°C to 1.0°C-below-average range that is required to qualify as a weak La Niña. Odds for an El Niño event to form are predicted to increase as we head towards the fall and winter of 2018, with the latest CPC/IRI Probabilistic ENSO Forecast calling for a 37% chance of an El Niño event during the August-September-October peak of the Northern Hemisphere hurricane season. El Niño events typically reduce Atlantic hurricane activity, due to an increase in wind shear over the tropical Atlantic.
|Figure 2. Sea surface temperatures (SSTs) in the benchmark Niño 3.4 region (in the equatorial Pacific) have hovered around 0.5°C below average over the past week; SSTs of 0.5° - 1.0°C below average in this region are required to be classified as weak La Niña conditions. Image credit: Levi Cowan, tropicaltidbits.com.|
Arctic sea ice falls to 2nd lowest March extent on record
Arctic sea ice extent during March 2018 was the second lowest in the 40-year satellite record, behind the record set in March 2017, according to the National Snow and Ice Data Center (NSIDC). While December, January, and February were characterized by very warm conditions over the Arctic, leading to record-low ice extent in January and February, March temperatures were mixed, with cool conditions over the Eurasian side and moderately warm conditions over the North American side.
Antarctic sea ice extent in March 2018 was not far below the 1981 to 2010 average.
Notable global heat and cold marks set for March 2018
Hottest temperature in the Northern Hemisphere: 45.5°C (113.9°F) at Nawabshah, Pakistan, 30 March and Pad Idan and Mohenjo Daro, Pakistan, 31 March
Coldest temperature in the Northern Hemisphere: -57.6°C (-71.7°F) at Geo Summit, Greenland, 7 March
Hottest temperature in the Southern Hemisphere: 45.9°C (114.6°F) at Roebourne Aero, Australia, 29 March
Coldest temperature in the Southern Hemisphere: -69.7°C (-93.5°F) at Dome A, Antarctica, 17 March
(Courtesy of Maximiliano Herrera.)
Major weather stations that set (not tied) new all-time heat or cold records in March 2018
Morondava (Madagascar) max. 40.5°C, 16 March
Timehri Airport (Guyana) min. 16.4°C, 19 March
Koror (Palau) max. 35.0°C, 22 March: New national record high for Palau
(Courtesy of Maximiliano Herrera)
One all-time national heat record broken in March 2018
So far in 2018, one nation has broken an all-time record for its hottest temperature in recorded history: Palau, which hit 95°F (35°C) at Koror on March 22. This beat the record set (most recently) back in February 2018: 93.9°F (34.4°C). 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.
Ten nations set monthly heat records in March 2018
An intense heat wave in the last week of March resulted in a swarm of national monthly heat records across the Middle East and parts of southern and western Asia. In Pakistan, temperatures hit 45.5°C (113.9°F) on March 30 in Nawabshah and on March 31 in Mohenjo Daro. These readings were the hottest on record for so early in the year in Pakistan, and just 0.1°C lower than the March record for all of Asia.
Ten nations set monthly heat records in March: Marshall Islands, Qatar, Armenia, Madagascar, Pakistan, Iraq, UAE, Turkmenistan, Tajikistan, and Uzbekistan. In February, national monthly heat records were set in the Marshall Islands, Falkland Islands, Kuwait, Qatar, Saudi Arabia, and Palau. The Marshall Islands also set a monthly heat record in January, so 17 national/territorial monthly heat records have been set so far in 2018.
(Courtesy of Maximiliano Herrera.)
National monthly cold records in 2018: 0
Bob Henson contributed to this post.