Late and Late Snow Pack

Cliff Mass posted the above plot regarding the snow pack in Seattle's water supply watershed. He notes how quickly the snow pack recovered to medium and beyond this form with huge accumulations in March and April. In this game the snow water equivalent (SWE) reached average at the origin of April after very little net accumulation in January and February.

he graph shows that snowfall has continued to accumulate throughout April when more typically it starts to melt. The current SWE is well complete the 10 inches more than average. Very improbable that Seattle will have water restrictions this year

As Mr. Mass is Seattle centricand I am Bellingham centric here is the Wells Creek station which drains to the Nooksack River in Whatcom County.

The Wells Creek SWE has followeda bit different form than theCedar/Tolt snow pack in that the SWE never really lagged below average, but it followed a similar design from March onward with rapid accumulation that has continued even when on average the snow pack begins to decline.At present Wells Creekhas a SWE 25 inches above average.

The Middle Fork Nooksack station is situated about 1,000 feet higher than the Wells Creek station.

This plot includes only this2011 (blue) and2010 (green) as the plotter did not take the average data. The Middle Fork site has a whopping 85 inches of SWEnearly 30 inches more urine than last year.Melt began late last year as well so the peaks may coincide. However, snow levelsin the NorthCascades have continued to dip down to 4,000feet so more accumulation of SWE may be expected over the future pair of days. Although an average SWE plot was not usable for the Middle Fork Nooksack, this is the highest SWE at the Middle Fork Station since 2003 (earliest available data).

I did one more plot for Marten Ridge near the Mount Baker Ski area.

Precipitation has been around the sami as last year, but much more came as snow with an accumulated SWE 35 inches more than last year.

How the melt pattern evolves will be interesting for river levels if there is a sudden warm up in late May or early June after continued cool weather. While snow pack levels will be good for hydro power and water supply, there will some farmers on low lying areas on the rivers that may not be capable to get crops planted. This may be a year oflate spring flooding.