Thursday, July 23, 2015

Snow and Snowpack

I've updated the Web page for snow data and information and added a new Web page for snowpack data and information. The former is about the general nature of snow data  collected, produced and disseminated for Mt. Rainier NP, but which applies anywhere.

The new Web page on snowpack focuses on snow water equivalent, with the SWE acronym, which is the depth of the water equivalent in a snow column. This data is key for water resources managers for river basin or watershed management for reservoirs, water supply, irrigation, floods, etc. to know the potential amount of runoff from the snowpack.

The Natural Conservation Service, Water Climate Center is responsible for the operation of the network of SNOTEL sites thoughout the western US. They operate three sites in and nearby Mt. Rainier NP and another 3 around the NP (five of the six available on a map of the NP).

In addition I looked at the period of record (1981-2015) for the Paradise site, southeast of the Jackson Visitors Center, for the variation of seasonal snowpack along with the date of the onset of permanent seasonal snow, peak of snowpack, onset and end of the snowmelt.

While a lot has been, and is being, made of the drought year (2015), nine of the last 10 years have been above 95% of the normal snowpack, seven of those years above normal, from 111% to 144%. This year (2015) is the anamoly from the recent trend.

In comparison, only eight of the previous twenty-three years were above normal, with the two record years occurring within a three year period and the intervening year almost normal. In short, low and extreme low snowpack years are the rarity in the last twenty-five years.

The results showed the obvious, that the variation of snow and snowpack is related to the general winter seasonal weather for any given year, meaning the patterns of rain and more so snow storms, and temperature from early fall to last spring into early summer.

The snowmelt season is related to the late spring (late May through June) weather and the early summer (late June into early July). Generally the snowmelt seasons runs from mid-May to mid-July, which in turn defines the wildflower season in the lower to upper elevations in the NP.

Anyway, the pages are up and I'm working on some new Web pages for the photo guide.

No comments: