micro-blowdown north of Glen Boulder?

[arghman]

I took these pictures last week. They are of the area north of the Glen Boulder ridge, looking north from the Glen Boulder Trail. (BTW, the trailless unnamed and ledgy east ridge of Gulf Peak south of the Gulf of Slides looked interesting and inviting from afar but spruce has me bushwhack-shy for anything above 3000ft) Note the flattened trees. Any comments as to what might be the cause? Weather downbursts?


closeup:

 

[weatherman]

cool!

First guess: microburst caused by a thunderstorm. All the trees fan out from one direction. Those can frequently be 70-90 mph. Second: Avalanche runout. (can't really tell how steep it is uphill from there).

Weatherman

 

[BrentD22]

My best guess

1998 Ice Storm did that to many many trees in and around New Hampshire. It's strange that it only happened to that selected area, but that summer I was on trail crews helping clear out the ice storm damage and we'd come across area that where desimatted and others that where not touched.

 

[forestgnome]

Arghman,

I've also noticed that ridge from Glenn Boulder Trail. I plan on taking a look some day.

That blow-down is interesting.

 

[BrentD22]

I looked more closely...

After saving and zooming way in (500%) I can say with an educated guess that the ice storm could not have caused that damage. The trees don't seem to have bowed over at all. They just blew down straight and all in the same direction. Ice might have been a factor (or heavy snow) and wind mixed in, but it's hard to say.

 

[el-bagr]

Avalanche damage, said with as much certainty as I can muster. GOS is heavy avalanche terrain -- remember that 38-degree slopes are ideal avalanche terrain, with slides possible to 25 degrees (or even lower, in unusual circumstances). GOS's slide paths are choked with bark-stripped, snow-bent alder.

Arghman, that easterly ridge of Gulf Peak is indeed interesting. So is the bowl to its south (mini-GOS): the bottom of the cirque hosts a talus pile or possible "rock glacier". Both the ridge discussed above and the Glen Boulder ridge (the two knuckles encircling the mini-GOS) have interesting alpine vegetation, despite relatively low altitude.

 

[giggy]

thats a crop circle from the aliens

just kidding -- probably a t-storm microburst.

 

[forestgnome]

el-bagr,

Wow! Thanks for the image and info. I'm going to explore that bowl this autumn.

 

[dug]

I don't think it's from the ice storm (too high and localized). When I was there this winter, I didn't think that particular area looked like avalanche danger as the runout looked pretty mild compared to the Gulf of Slides itself. The snow certainly didn't look like there had been any sliding. This is, of course, assuming the area I was looking at is where this is, which I cannot be sure.

If I had to venture a guess, I would say wind caused the initial blowdown, and once it opened up it created more of an area to blowdown?