Sunday, April 1, 2012

March to April

2010-11 (green) and 2011-12 (blue) SWE at Paradise SNOTEL site

Counter to the proverb, this year March came in like a lion and is leaving like a lion, and was a lion most of the days of the month. And April is not looking any different going into the first week of the month. That may change during the month as we don't know beyond what we think or hope, but for now while spring in the lowland will slowly appear, it won't in the mountains for a few more weeks. We may get clear, sunny weather, but only between the storms bringing more snow.

This is why the graph above is important for water resource managers to determine the snowpack and Snow Water Equivalent (SWE) when the snowmelt season begins, normally early to mid May, and the spring weather controls the rate of the snowmelt into the streams and rivers and eventually into the reservoirs.

In the case of Mt. Rainier three of the four rivers draining the mountain, the Nisqually, Cowlitz and White River, a tributary to the Puyallup River, all flow into reservoirs downstream. Only some of the tributaries of the Puyallup River draining the mountain, specifically the Carbon River and two Mowich Rivers, don't have any reservoirs to retain or divert the snowmelt runoff downstream.

You can watch the snowmelt in part of the flow in the downstream rivers with the USGS real-time streamflow table and use the "Predefined Displays" for the individual river basins, specifically the Cowlitz River, the Nisqually River and the Puyallup River basins.

That's the news so far, snow now and more snow acomin'. Take heed, stay warm and dry, and most of all, enjoy your visit. Remember it's the last weekend of the snowplay area at Paradise. Only winter camping in designated area at Paradise or in the backcountry allow with a permit.

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