banner.JPG (1211253 bytes)

Caboolture Gliding Club

| Home Page  | Articles Index | Articles Archive |

Wave tree damage?

20-Jun-13

 

 

--------------------

From: Brisbane Gliding Adventures
Date: 19/06/2013 9:08 PM
Subject: Wave cloud and tree damage?
To: "aus-soaring"

My dad (life long Forestry worker Henry) told me many years ago about some strange damage to pine trees that he had found in the back (western-most) paddock of the Strahorn State Forest near Peak Hill, in the Central West of NSW. 

(For those who have flown out of Narromine, it is the 10,000 acres of trees smack bang in the middle of farming country south of Narromine ... midway in a line between Peak Hill and Tullamore).

The way he described it, the branches of trees had been shorn off as though something had scooped down from the tops of the trees getting gradually lower and lower to ground level then gradually back up to the tree-top level again on the other side of a wide "flattened to ground-level" area.

I attended a Gliding Queensland lecture last night on Wave Clouds where the presenter (Wes McIver) mentioned briefly that wave cloud formations can actually touch down to ground level on rare occasions.

I have been thinking today that maybe this could explain the pattern of tree damage that my Dad had referred to all those years ago.

Maybe I am just putting 2 and 2 together and coming up with 5?

Kevin Rodda

    

--------------------
From: Brisbane Gliding Adventures
Date: Thu, Jun 20, 2013 at 3:24 PM
Subject: Wave cloud and tree damage?
To: aus-soaring

Email received from Wes McIver this morning ...

Kevin good morning, I think your 2 + 2 = 4. 

Standing waves do touch down and do cause considerable damage. 

As the frequency of the wave changes, the air movement on the ground with these meteorological phenomena appears to move from calm at a fixed point to gale force within seconds. 

The frequency changes cause the wave bounce to move up wind and downwind sometimes quite rapidly. 

The wind velocity on the ground in these conditions can often reach speeds of 200+ km/hr and sounds very much like a train arriving. 

I have seen whole forests flattened by these winds. 

All the best with your gliding and safe journeys. 

Best regards, 

Wes

--------------------

 

Kevin Rodda