State of the Climate in 2003

giving way to near-neutral ENSO conditions for the remainder of the year. Despite the cessation of El Niño during the boreal spring, the ENSO warm event affected regional precipitation anomalies over a broad area of the Pacific basin, including wet anomalies along the west coast of South America, and dry anomalies in eastern Australia, the southwest Pacific, and Hawaii. The global mean surface temperature in 2003 was within the highest three annual values observed during the period of regular instrumental records (beginning in approximately 1880), but below the 1998 record-high value. Global surface temperatures in 2003 were 0.46°C (0.83°F) above the 1961–90 mean, according to one U.K. record, which ranked as third highest in this archive. In the U.S. temperature archive, the 2003 anomaly was also 0.46°C (0.83°F), equivalent to the 2002 value, which ranked second over the period of record. Similar to the surface temperature anomalies, satellite retrievals of global midtropospheric temperatures ranked 2003 as third warm-est relative to the 1979–98 mean value. The hurricane season was extremely active in the Atlantic basin, with a total of 16 tropical storms, seven hurricanes, and three major hurricanes in 2003. Five of these tropical cyclones made landfall in the United States, three made landfall in northeastern Mexico, and a tropical storm affected Hispañola. In addition, Nova Scotia and Bermuda experienced devastating impacts from hurricanes in 2003. Another notable aspect of the season in the Atlantic was the formation of five tropical storms over the Gulf of Mexico, which tied the season high observed in 1957. In addition, three tropical storms formed outside of the normal (June– November) hurricane season in 2003—one in April and two in December—which made this the first season since 1887 that two tropical storms have formed during December in the Atlantic basin. Also of note was the below-normal activity in the eastern North Pacific basin. There were no major hurricanes in this basin during the 2003 season, which made this the first year since 1977 with no category 3–5 storms. Despite the below-normal activity, four tropical cyclones made landfall on the Pacific coast of Mexico, two as hurricanes and two as tropical storms, which was twice the long-term mean. The summer of 2003 was one of the warmest on record across parts of Europe, where a heat wave affected most of Central and Western Europe. Two distinct periods of exceptional heat occurred during the season—the first in …