A new study has been published showing snowpack trends in the Cascade Mountains from 1930 to 2007.

"A New Look At Snowpack Trends In the Cascade Mountains" examined the changes in Cascade Mountain spring snowpack since 1930. Authors are Mark T. Stoelinga, Mark D. Albright, and Clifford F. Mass of the Department of Atmospheric Sciences, University of Washington.

According to the abstract: "Three new time series facilitate this analysis: a water-balance estimate of Cascade snowpack from 1930-2007 that extends the observational record 20 years earlier than standard snowpack measurements; a radiosonde-based time series of lower-tropospheric temperature during onshore flow, to which Cascade snowpack is well correlated; and a new index of the north Pacific sea-level pressure pattern that encapsulates modes of variability to which Cascade spring snowpack is particularly sensitive."

The paper can be found in the American Meteorological Society's Journal of Climate at http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2009JCLI2911.1/

"Cascade spring snowpack declined 23 percent during 1930-2007," according to the abstract. "This loss is nearly statistically significant at the 5 percent level. The snowpack increased 19 percent during the recent period of most rapid global warming (1976–2007), though this change is not statistically significant due to large annual variability.

"From 1950-1997, a large and statistically significant decline of 48 percent occurred. However, 80 percent of this decline is connected to changes in the circulation patterns over the north Pacific Ocean that vary naturally on annual to interdecadal time scales. The residual time series of Cascade snowpack after Pacific variability is removed displays a relatively steady loss rate of 2.0 percent per decade, yielding a loss of 16 percent from 1930-2007. This loss is very nearly statistically significant, and includes the possible impacts of anthropogenic global warming.

"The dates of maximum snowpack and 90 percent melt-out have shifted 5 days earlier since 1930. Both shifts are statistically insignificant. A new estimate of the sensitivity of Cascade spring snowpack to temperature of -- 11 percent per degree Celsius, when combined with climate model projections of 850 hPa temperatures offshore of the Pacific Northwest, yields a projected 8 percent loss of Cascade spring snowpack due to anthropogenic global warming between 1985 and 2025."