Earliest Melt-Out On Record At Mount Hood Test Site

May 22, 2015

11pm Friday…

Today was “Melt-Out” day at the Mt. Hood SNOTEL site at 5,400′ in the lower part of the Timberline Ski Area.  That’s the spot where the media goes once each month from late December to late March to check out the snowpack.

Have you ever wondered how long it takes all the snow in the Cascades to melt? Of course it depends on the elevation, with higher elevations (cooler temps) taking longer.  The snow depth sensor shows 4″ on the ground, although that is an imperfect measurement since it’s measured from many feet above via sound waves…or something along those lines.  The Snow Water Equivalent (SWE) measurement is more reliable.  It is a “snow pillow” that measures snow water equivalent by sensing weight on a fluid-filled bag.  Today that measurement dropped below 2″.  It’s 1.60″ right now and was 3.40″ 24 hours ago so it should be gone tomorrow.

Here is a chart showing the LAST DATE EACH SPRING/SUMMER that the SWE went below 2″.  Data at this location at 5,400′ goes back to 1981.

MeltOutDate

You can see the earliest WAS the drought year 1992 when the snow disappeared by May 25th. But the earliest is now May 22, 2015.  The latest was just three years ago in 2011, when the last of the snow disappeared in late July. Now the data period is quite short; only 34 years, so don’t try to draw any earth-shattering conclusions, but the trend is now pretty much flat for the past third of a century.

I think it’s fair to make these two statements as well:

1. At the 5,400′ elevation on Mt. Hood, the snow is not melting any earlier than in previous decades.

2. The Cascade snowpack AT THAT ELEVATION and IN THAT LOCATION is sure not disappearing!

3. This was a terrible snow year and we sure don’t want to see that repeated!

Chief Meteorologist Mark Nelsen