NH Snow Cover Extent
|February 2017||Snow Cover Extent||1981-2010 Anomaly||Trend
(out of 51 years)
|million km2||million mi2||million km2||million mi2||million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: Global Snow Laboratory, Rutgers University. Period of record: 1967–2017 (51 years)
The Northern Hemisphere snow cover extent (SCE) during February was 45.96 million square km (17.75 million square miles), 370,000 square km (150,000 square miles) above the 1981-2010 average. This was the 22nd largest (28th smallest) Northern Hemisphere SCE in the 51-year period of record and largest since 2014. The North American SCE was below average while the Eurasian SCE was above average. For the winter season (December 2016-February 2017), the Northern Hemisphere SCE was the 10th largest on record at 1.47 million square km (568,000 square miles) above average. This was the largest winter SCE for the Northern Hemisphere since 2013.
During February, the North American SCE was 420,000 square km (160,000 square miles) below the 1981-2010 average — the 15th smallest on record. An active storm pattern across western North America resulted in above-average snow cover across the western U.S. and Canada. Above-average temperatures and below-average precipitation was associated with below-average snow cover in central and eastern United States. The contiguous U.S. SCE was the 12th smallest on record, the Canadian SCE was the 21st largest on record, while the Alaska SCE was the 11th smallest. The winter North American SCE was the 18th largest on record at 330,000 square km (127,000 square miles) above average.
The Eurasian February SCE was 29.26 million square km (11.30 million square miles), 780,000 square km (300,000 square miles) above average. This ranked as the 19th largest February SCE for Eurasia. Above-average snow cover was observed across central and eastern Europe, southern Kazakhstan, western Iran, and parts of northern and western China. Below-average snow cover was observed in Western Europe, Turkey, and parts of southern China. The winter Eurasian SCE was the ninth largest on record at 1.14 million square km (440,000 square miles) above average. This was the largest winter SCE for Eurasia since 2013.
Sea Ice Extent
|February 2017||Sea Ice Extent||
(out of 39 years)
|million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2017 (39 years)
According to the National Snow and Ice Data Center (NSIDC), the Northern Hemisphere (Arctic) sea ice extent — which is measured from passive microwave instruments onboard NOAA satellites — averaged for February 2017 was 14.28 million square km (5.51 million square miles), 1.18 million square km (460,000 square miles), or 7.63 percent, below the 1981-2010 average. This was the smallest February Arctic sea ice extent on record, dipping below the previous record of 14.32 million square km (5.53 million square miles) set just last year in 2016. Sea ice expanded slowly in early February with ice growth nearly stopping for a few days. The sea ice expanded rapidly mid-month for about a week, but slowed once again the last part of February. Most of the ice growth during the month occurred in the Bering Sea, although overall ice in the region remained below average. In the Sea of Okhotsk, sea ice substantially decreased in mid-month, but rebounded to near-average levels by the month's end. Below-average sea ice was also observed in the Barents and Kara Seas with nearly no ice growth in the region during February. The annual sea ice maximum extent is expected to occur in March at near-record low levels. February Arctic ice extent is decreasing at an average rate of 3.0 percent per decade.
The February Southern Hemisphere sea ice extent was 2.35 million square km (910,000 square miles), which was 760,000 million square km (290,000 square miles), or 24.44 percent, below the 1981-2010 average. This was the smallest monthly Southern Hemisphere sea ice extent (of any month) on record and 170,000 square km (60,000 square miles) smaller than the previous record set in February 1997. On February 13th, the daily Antarctic sea ice extent reached a new record low at 884,000 square miles and continued to drop throughout the month and was 822,400 square miles on February 28th. The annual minimum extent will likely occur in March, setting a new record low. Most of the Amundsen Sea off the west coast of Antarctica was ice free for all of February with near-average sea ice across other regions. Southern Hemisphere sea ice extent is increasing at an average rate of 2.9 percent per decade, with substantial inter-annual variability.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.