Shrinking Snowpack In Lower Cascades

February 26, 2016

11pm Friday…

Take a look at the change in snowpack in the mountains over the past two months…

PERCENTAGE OF NORMAL SNOW WATER IN LATE DECEMBER:

MarkSnowpack_Oregon_PlusFacts

PERCENTAGE OF NORMAL RIGHT NOW:

MarkSnowpack_Oregon_PlusFacts

Quite a change isn’t it?  What was turning out to be a HUGE year for snowpack (and water supplies) across the region has now turned into a ho-hum snowpack.   Most areas are probably okay for water this coming dry season, but as of now the current snowpack probably won’t help entirely erase the drought in parts of Eastern Oregon.

Why?

It’s due to a classic El Nino split jet stream and subtropical ridging along the West Coast.  We’ve been seeing that for the past 8 weeks, since right after the New Year.  This is VERY NORMAL in an El Nino winter…most of the action tends to happen in the first half of the winter.    Due to this, we’ve had very warm weather as detailed in posts over the past few weeks.  Look at the snow depth (in red) and snow water equivalent (blue) at two sites near 4,000′ SE of Multnomah Falls and just east of Trillium Lake so far this year.  You see the snow depth at both peaked in late December, with a 2nd max just a couple weeks ago.  These lower elevations typically peak in the next few weeks even in a normal winter, as a result most likely below the 4,000′ elevation we’ll see the snowpack continue to dwindle in early/mid March with no cold/wet pattern in site.

Luckily for ski areas the few cold/wet systems have arrived just ahead of or during the weekends when most crowds hit (this evening’s rain wasn’t real helpful for night skiing).

As of now there appears to be enough snow to keep even the lower ski areas open until Spring Break (begins 3 weeks from today), unless we get some unusually warm rains.

Looking ahead, it sure does look like March with mild temperatures and occasional rain.  You do see breaks in the rain in the GFS meteogram from tonight’s 00z run:

gfs

Enjoy the dry day Saturday and if we get lucky maybe a hail shower or rumble of thunder Sunday afternoon?  Sorry, that’s the most excitement I can find in the weekend forecast.

Chief Meteorologist Mark Nelsen