Trends in NHEMI Snow Cover

Plot of CPC/s NH snow area data...as of the end of SEP.

The black line near the chart/s center is the yearly average from the start of the period-of-record.

In 1977...the 5-year moving average snow area was 25.3 x 10^6 km^2. In 2006...the 5-year moving average snow area was 24.1 x 10^6 km^2...a change of ~1.2 million square kilometers.

The data generally show modest year-to-year variability...the exception being OCT...which has slowly increased by 6.7 million square kilometers since 1988.