April 1st Snow Water Equivalent: Historical

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<hr /><p> Historical April 1st Snow Water
Equivalent (SWE), a measure of the total amount of water contained in
the snowpack. April 1st is the approximate current timing of peak annual
snowpack in the mountains of the Northwest. Results are shown only for
watersheds with an average historical April 1st SWE of at least 0.4
inch. Geographic units: HUC10. <br /></p><p>These data are part of a set that includes historical
conditions (1970-1999, in inches) and the projected changes (in percent)
for ten global models. Two time periods are considered: the 2040s
(2030-2059) and the 2080s (2070-2099), based on a moderate greenhouse
gas scenario (A1B). <br /></p><p><span style='font-style:italic;'>When rendered and displayed in Map Viewer (web map): </span>Data
classes and symbology by Robert Norheim, Climate Impacts Group, based
on the CMIP3 projections used in the IPCC 2007 report. </p><p>Data source: Hamlet et al. 2013.</p>