NH Snow Cover Extent

Data were provided by the Global Snow Laboratory, Rutgers University. Period of record is 1967-2010 (44 years).

The Northern Hemisphere snow cover extent during November 2010 was slightly above-average, marking the second November in a row with above-average snow cover. During November, the hemispheric snow cover extent ranked as 20th largest (26th smallest) on record. The average Northern Hemisphere November snow cover extent for the 1967-2010 period of record is 33.5 million square kilometers. The snow cover extent during Autumn (September–November) was also above-average for the Northern Hemisphere ranking as 21st largest (24th smallest) on record. The 44-year average Northern Hemisphere autumn snow cover extent for the period of record is 19.2 million square kilometers.

Across North America during November, snow cover extent was above average, ranking as 13th largest in the 45-year period of record. This is the first time that North America has had above-average snow cover extent during November since 2006. Canada had below-average snow cover extent during November, while the contiguous U.S. and Alaska had much above-average snow cover extent. The low snow cover across Canada during November was attributable to above normal temperatures for the northern and eastern parts of the country as well as below normal precipitation. The average North American November snow cover extent is 13.3 million square km for the period of record. Snow cover for autumn 2010 was slightly above average for North America, ranking as the 18th largest since 1967. The average North America autumn snow cover extent is 8.5 million square kilometers for the 44-year period of record.

Eurasian snow cover was slightly below-average during November, ranking as 24th smallest (21st largest). A storm system moving across Western Europe the last week of November brought widespread snowfall, increasing the snow cover extent for the month. The average Eurasian snow cover extent in November is 20.2 million square kilometers for the period of record. Eurasia's snow cover extent during autumn 2010 was above average (23rd largest). The 44-year average Eurasian snow cover extent in autumn is 10.7 million square kilometers for the period of record.

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Sea Ice Extent

According to the National Snow and Ice Data Center (NSIDC), the Northern Hemisphere sea ice extent — which is measured from passive microwave instruments onboard NOAA satellites — averaged for November 2010, was 9.89 million square km (3.82 million square miles). The monthly extent was 12.5 percent below the 1979–2000 average and ranked as the second smallest November Northern Hemisphere sea ice extent in the satellite record, behind 2006. During November 2006, the Northern Hemisphere sea ice extent had an average extent of 9.84 million square km (3.80 million square miles). Northern Hemisphere ice extent for November has decreased at a rate of 4.6 percent per decade.

During November, Arctic ice extent was unusually low in both the Atlantic and Pacific sectors of the Arctic and in Hudson Bay. Typically by the end of November, half of Hudson Bay is ice covered. By November 30th, 2010, only 17 percent of the bay was covered by sea ice. Air temperatures over the Siberian and Alaskan side of the Arctic were 5 to 9 degrees F (3 to 5 degrees C) warmer than normal over the course of November. These warm temperatures contributed to much-below-average ice coverage for the Beaufort, Bering, and Chukchi seas. Air temperatures over Baffin Bay were also unusually warm (14 degrees F [8 degrees C] above-average) which caused below-average ice coverage between Baffin Island and Greenland, as well as the Barents Sea.

Meanwhile, the November 2010 Southern Hemisphere sea ice extent was 4.09 percent above the 1979–2000 average. This was the largest November Southern Hemisphere sea ice extent on record. Southern Hemisphere sea ice extent for November has increased at an average rate of 0.7 percent per decade. Antarctic sea ice usually expands during the cold season to a September maximum, then contracts during the warm season to a March minimum.

For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page, provided by NOAA's National Snow and Ice Data Center (NSIDC).

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Citing This Report

NOAA National Centers for Environmental Information, Monthly Global Snow and Ice Report for November 2010, published online December 2010, retrieved on March 29, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/global-snow/201011.