Climate assessment for 2000

The global climate in 2000 was again influenced by the long-running Pacific cold episode (La Nina) that began in mid-1998. Consistent with past cold e pisodes, enhanced convection occurred across the climatologically convectiv e regions of Indonesia and the western equatorial Pacific, while convection was suppressed in the central Pacific. The La Nina was also associated wit h a well-defined African easterly jet located north of its climatological m ean position and low vertical wind shear in the tropical Atlantic and Carib bean, both of which contributed to an active North Atlantic hurricane seaso n. Precipitation patterns influenced by typical La Nina conditions included 1) above-average rainfall in southeastern Africa, 2) unusually heavy rainf all in northern and central regions of Australia, 3) enhanced precipitation in the tropical Indian Ocean and western tropical Pacific, 4) little rainf all in the central tropical Pacific, 5) below-normal precipitation over equ atorial east Africa, and 6) drier-than-normal conditions along the Gulf coa st of the United States. Although no hurricanes made landfall in the United States in 2000, another active North Atlantic hurricane season featured 14 named storms, 8 of which became hurricanes, with 3 growing to major hurricane strength. All of the named storms over the North Atlantic formed during the August-October perio d with the first hurricane of the season, Hurricane Alberto, notable as the third-longest-lived tropical system since reliable records began in 1945. The primary human loss during the 2000 season occurred in Central America, where Hurricane Gordon killed 19 in Guatemala, and Hurricane Keith killed 1 9 in Belize and caused $200 million dollars of damage. Other regional events included 1) record warm January-October temperatures followed by record cold November-December temperatures in the United States , 2) extreme drought and widespread wildfires in the southern and western U nites States, 3) continued long-term drought in the Hawaiian Islands throug hout the year with record 24-h rainfall totals in November, 4) deadly storm s and flooding in western Europe in October, 5) a summer heat wave and drou ght in southern Europe, 6) monsoon flooding in parts of Southeast Asia and India, 7) extreme winter conditions in Mongolia, 8) extreme long-term droug ht in the Middle East and Southwest Asia, and 9) severe flooding in souther n Africa. Global mean temperatures remained much above average in 2000. The average l and and ocean temperature was 0.39 degreesC above the 1880-1999 long-term m ean, continuing a trend to warmer-than-average temperatures that made the 1 990s the warmest decade on record. While the persistence of La Nina conditi ons in 2000 was associated with somewhat cooler temperatures in the Tropics , temperatures in the extratropics remained near record levels. Land surfac e temperatures in the high latitudes of the Northern Hemisphere were notabl y warmer than normal, with annually averaged anomalies greater than 2 degre esC in parts of Alaska, Canada, Asia, and northern Europe.