Greetings from Silverton,
Event D4 arrived Monday, March 28 and ushered in a series of storms that lasted until Thursday.
The official storm (Storm #18) came through Senator Beck Basin starting between 1500-1600 on Monday, March 28 thru 400 Wednesday, March 30. The storm was preceded with strong S'ly winds and the beginnings of dust (see wind rose below).
The high winds continued while the dust and snow fell. The first 28 hours of the storm average hourly gusts were 63 mph, creating real blizzard like conditions at times in Silverton and surrounding areas. We received 9.7" (24.7 cm) of new snow accumulation and a solid 1.0" (25 mm) of precipitation. D4 is a diffuse layer within this 9.7" (24.7 cm) of snow with bands of higher concentrations throughout. On Wednesday, March 30, around 7:00am the winds shifted out of the N. We continued to see another 0.24" (6 mm) of precipitation until late Thursday night, but there was a gap of precipitation greater than 12 hours thus ending the official duration of the storm. The D4 band of dust was buried ~4" (10 cm) by this system that arrived on Wednesday/Thursday (see picture below).
To summarize WY2016 dust events in the SASP snowpack thus far at Senator Beck:
- D4, contained within a 9.7" (24.7 cm) band of snow now sits ~ 4" (10 cm) below snow surface.
- D3 sits on a melt freeze crust approximately 9.8" (25 cm) below D4.
- D2 is located 7" (18 cm) below D3.
- D1 is the lowest layer at 17" (43 cm) above the ground surface.
We received the mass loading results for D3 from the USGS. D3 contained 2.210 g/m² of dust. This brings our total dust deposited on the snowpack from D1, D2, and D3 for WY2016 to 6.274 g/m². You can see how this compares to previous years at the CODOS website: http://www.codos.org/#mass-loading-data
The week to come looks pretty tame with only a 20% chance of precipitation in the Silverton area, snow showers, in the 2-5" range look to favor the north and central mountains.