U.S. EXPERIENCES FIRST COOLER-THAN-AVERAGE MONTH SINCE MARCH 2001;
GLOBAL TEMPERATURE FOR MARCH WARMEST ON RECORD
April 12, 2002 Arctic air brought in by the jet stream in March kept temperatures relatively low throughout the United States, making it the first cooler-than-average month since March 2001. However, it was the warmest March for the globe since reliable records began in 1880, according to NOAA scientists. (Click image for NOAA's March 2002 statewide temperature ranks.)
Although temperatures throughout a large part of the United States and Canada were cooler than average in March, warmer than average temperatures were widespread across most other global land areas. Ocean surface temperatures were also warmer than average in the eastern equatorial Pacific as the evolution of oceanic conditions continued to indicate a developing El Niño episode, and the global sea surface temperature was the second warmest on record.
The average global temperature for land and ocean surfaces combined (based on preliminary data) was 1.39 F (0.77 C) above the 1880-2001 long-term mean, 0.16 F (0.09 C) higher than the previous record warm March, which occurred in 1998 during the latter stages of the last El Niño episode. Global temperatures have increased approximately 1 F (0.6 C) since 1900, but the rate of warming during the past 25 years is almost three times higher, according to NOAA's Climatic Data Center in Asheville, N.C.
The global sea surface temperature in March was 0.83 F (0.46 C) above average, only 0.05 F (0.03 C) less than the record warm March of 1998, and the global land surface temperature (2.70 F/1.50 C above average) was also the second warmest on record, slightly cooler than the warmest March which occurred in 1990. Monthly temperatures more than 7 F (4 C) above average stretched from Eastern Europe to the Russian Far East and much of Eastern China, and temperatures across a large part of Africa and the northern two-thirds of South America were also warmer than normal. Conversely, temperatures more than 6 F (3 C) below average covered much of central and western Canada and the northern United States.
Record high global monthly temperatures were also established in January 2002 and November 2001. The year-to-date temperature anomaly for January-March equaled the previous record established in 1998 for the three-month period.
The anomalous warmth of the past several months was largely absent in March throughout much of the United States as the orientation of the jet stream consistently brought arctic air into the center of the nation. The average March temperature in the contiguous U.S. was 40.5 F (4.7 C), almost 2 F (1.1 C) below the 1895 2001 average, the first cooler than average month since March 2001. Only ten states (Florida, North Carolina, Delaware, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, Vermont and New Hampshire) had monthly temperatures significantly above average. Alaska was also warmer than average in March, 2.8 F (1.6 C) above the 1961-1990 mean.
Most states west of the Mississippi were cooler than average, including Montana which had its fifth coldest March on record. The return of colder than normal temperatures was notable in the northern Plains, in cities such as Bismarck, N.D., where March was colder than any month of the 2001-2002 winter season (December February). The average monthly March temperature was 18.8 F (-7.3 C), more than 0.5 F (0.3 C) cooler than each of the previous three months.
After several months of drier than average conditions, normal to above-normal rain and snowfall returned to much of the eastern third of the nation in March. Below average precipitation totals were largely confined to the western United States and only eight states (California, Nevada, Arizona, Utah, Colorado, Kansas, Nebraska and Iowa) in the contiguous United States were significantly drier than average. However, drought continued to affect large parts of the United States, particularly areas along the eastern seaboard from Maine to Georgia and parts of the southern Plains and western United States.
The October through March six-month period was the driest October through March on record in Virginia, Maryland, New Jersey and Connecticut and the second driest in Delaware and Arizona. Precipitation in eight other states from Georgia to Maine was much below average during the same period. In the Northeast, drought emergencies have recently been declared in New York City, New Jersey, southeastern Pennsylvania, parts of northern Maryland and all but one county in New Hampshire. In Georgia and the Carolinas, March rainfall boosted streamflows and topsoil moisture, but many wells ran dry and local water-use restrictions remain in effect in many areas.
A continuation of below normal precipitation in March led to worsening drought conditions in much of the West. Although some improvement occurred in the northern Rockies, drought conditions which began more than two years ago continued throughout a large part of Montana and the entire state was declared a drought disaster area by the U.S. Agriculture Secretary in late March.
Conditions in the Pacific Northwest continued to improve in March, but drought severity worsened in parts of the Southwest. January through March was the third driest such three-month period in the Southwest (Arizona, New Mexico, Utah and Colorado) and the seventh driest in the West (California and Nevada). Mountain snowpack levels are less than 70 percent of average throughout a large part of Colorado, Utah and Wyoming, and below 50 percent in New Mexico and Arizona. The wildfire season is already active in many areas with a continuation of enhanced fire risk likely.
NOAA's National Environmental Satellite, Data, and Information Service (NOAA Satellite and Data Service) is the nation's primary source of space-based meteorological information and climate data. In addition to search and rescue, NOAA's environmental satellites are used for weather forecasting, climate monitoring, and other environmental applications such as volcanic eruptions, ozone monitoring, sea surface temperature measurements and wild fire detection. NOAA Satellite and Data Service also operates three data centers, which house global data bases in climatology, oceanography, solid earth geophysics, marine geology and geophysics, solar-terrestrial physics, and paleoclimatology.
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