Windthrow and Synoptic Climatology

Larry Stamm larryst at vis.bc.ca
Tue Jun 9 09:13:01 EST 1998


On Fri, 5 Jun 1998 04:56:28 -0700, Brendan Murphy <murphyb at unbc.ca> wrote:

>Hi,
>
>I am interested in learning of any windthrow studies which have examined
>the synoptic climatology of severe winds.
>
>Thanks in advance,
>
>- Brendan Murphy
>  University of Northern British Columbia
>  Prince George, B.C.  CANADA

Windthrow is a big problem here in the Robson Valley, especially in winter, but
the severe winds that cause it are usually localized, and are a result of a
complex interaction betwen the terrain and the general air mass movement.  I
think it would be hard to predict windthrow danger in any one area merely from
the synoptic charts.  The surface weather in the Robson Valley can be
drastically different from Prince George even when both places are affected by
the same air mass.  The same statement holds true for different locations and
altitudes in the Robson Valley.  Wind velocities can vary by as much as 100km/hr
or more in the distance of a few km or a few hundered metres in altitude.

So for mountainous areas, I think the best that could be done is a historic
comparison of the synoptic conditions that held during major windthrow events,
keeping in mind the age and species mix of the affected stand.  The Forest
Service has these observations on file for individual episodes, but I am aware
of no broad compilations or studies.  To lay out a windfirm cutblock boundary
almost requires the kind of familiarity with the wind patterns in a particular
drainage that only comes from field observation.

Good luck with your search,
Larry

--
Larry Stamm
larryst at vis.bc.ca
http://www.mcbridebc.com/luthier/



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