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This American Winter Warmest on Record

ASHEVILLE, North Carolina, March 12, 2000 (ENS) - With the first day of spring just a week away, climate scientists are already calling this winter the warmest since climate recordkeeping began in 1895.

The winter of 1999-2000, December through February, was the warmest on record for the United States, according to statistics calculated by scientists at the National Oceanic and Atmospheric Administration (NOAA). The last three winters have been the three warmest on record, NOAA climate experts say.

Scientists are working from the world's largest statistical weather database at NOAA's National Climatic Data Center in Asheville, North Carolina which holds data that goes back through the entire 105 year history of record keeping.

A shrimper on Doboy Sound, Georgia silhouetted in the setting sun. (Photo by F. Hay courtesy NOAA) Working from this and current data, the National Climatic Data Center's seasonal winter temperature forecasts for the past two winters have called for much of the country to have above normal temperatures. These forecasts were based on the expected impacts of the Pacific Ocean cooling pattern known as La Niña and longer term global warming trends. The winter season preliminary temperatures averaged 38.4 degrees Fahrenheit (F), 0.6 degrees F warmer than the previous record, set just last year.

In addition, the third warmest winter on record occurred in 1997-1998, though tied with 1991-1992, at 37.5 degrees F.

The 1999-2000 winter continues the pattern of warm winters established in 1980 with 67 percent of the winter seasons since then being warmer than the long term average.

During the past winter, every state in the continental United States was warmer than its long term average, with 21 states from California to the Midwest ranked as much above average.

Oklahoma experienced its warmest winter on record with Kansas, Nebraska, and Montana experiencing their second warmest.

U.S. map showing below normal snow water equivalent to March 9. Red areas indicate less than 75 percent of normal snow water. Shades of orange indicate levels of 100 percent to less than 76 percent of normal snow water. Yellow and green areas indicate above normal levels. (Map courtesy NOAA) Dryness also characterized the winter season, with 1999-2000 ranked as the 16th driest on record. Long-term dryness intensified in the northern Gulf states with Louisiana reporting its driest winter on record and Alabama and Mississippi their third driest. New Mexico and Arizona also experienced much below normal rainfall for the season. The only regions experiencing a wet season were the northern and central Rockies and a zone from the central Plains eastward to the Ohio Valley.

This winter Canadian air masses were not a major factor, the NOAA climate scientists say. Many locations from the northern Plains to New England established records for the latest date of their first seasonal snowfall, latest date without a temperature below freezing, longest snow-free period, or longest period between sub-zero temperatures.

Although the eastern states experienced heavy snowfalls in the last two weeks of January, the accompanying cold air was short lived, as February established hundreds of daily maximum temperature records. Numerous locations from the northern Plains to New York set or tied their all-time maximum temperature records for the month.

These data sets are based on what is referred to as the boreal, or northern, winter in December, January and February, when the Northern Hemisphere experiences colder winter weather while the Southern hemisphere is experiencing summer weather patterns.

The 1999-2000 season global land and ocean temperatures ranked as the 6th warmest on record, following the two warmest boreal winter seasons set in the past two years. Ocean temperatures ranked as 10th warmest at 0.5 F degrees above average. Land temperatures remained well above average, with this season's departure from long term average ranked as the 4th warmest on record, at 1.4 F degrees above average.

Agronomist Jim Smart and Mexican farmers Miguel Morales Beltran and Hector Rodriquez Mediola discuss the 1996 drought that caused this irrigation ditch near Rio Bravo, Mexico, to dry up. (Photo by Jack Dykinga courtesy U.S. Dept. of Agriculture) Globally, the warmest global land temperature departures from the average occurred in the past two boreal winters. Nearly the entire northern hemispheric land mass was warmer than the long term average with only North Africa, the Mediterranean countries, Central America and parts of extreme eastern Asia below average. Most of North America, northern Europe, and Russia experienced well above normal warmth for the season.

Globally, precipitation was above average through central and northern Europe, most of South America, with the largest anomalies across southern Africa, Southeast Asia, the Pacific Islands, and Australia.

Above average rainfall in February, compounded by a dissipating tropical system, resulted in catastrophic flooding in countries in southeastern Africa. Major areas of dryness were the Mediterranean countries, Japan, and most of North America.

In addition, the Earth's ice cover is melting in more places and at higher rates than at any time since record keeping began. Reports from around the world compiled by the Worldwatch Institute and released last week show that global ice melting accelerated during the 1990s-which was also the warmest decade on record.

Scientists suspect that the enhanced melting is among the first observable signs of human induced global warming, caused by the unprecedented release of carbon dioxide and other greenhouse gases over the past century. Glaciers and other ice features are particularly sensitive to temperature shifts.

The Earth's ice cover acts as a protective mirror, reflecting a large share of the sun's heat back into space and keeping the planet cool. Loss of the ice would not only affect the global climate, but would also raise sea levels and spark regional flooding, damaging property and endangering lives. Large-scale melting would also threaten key water supplies as well as alter the habitats of many of the world's plant and animal species.

Some of the most dramatic reports come from the polar regions, which are warming faster than the planet as a whole and have lost large amounts of ice in recent decades. The Arctic sea ice, covering an area roughly the size of the United States, shrunk by an estimated 6 percent between 1978 and 1996, losing an average of 34,300 square kilometers-an area larger than the Netherlands-each year.

The massive Antarctic ice cover, which averages 2.3 kilometers in thickness and represents some 91 percent of Earth's ice, is also melting. So far, most of the loss has occurred along the edges of the Antarctic Peninsula, on the ice shelves that form when the land-based ice sheets flow into the ocean and begin to float. Within the past decade, three ice shelves have fully disintegrated, scientists have noted.

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