Ok, new info, even better answer: a big wall of air is more like a Haboob. I
love that name. It still comes from a thunderstorm, or something like it,
somewhere out there...
----- Original Message -----
From: "Bill Gibson" <bgibson@CYBERTRAILS.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, August 12, 2002 9:45 PM
Subject: Re: Trip got interesting

> That's a downburst; normal monsoon weather. One smashed up Sky Harbor
> airport in Phoenix, and took the asphalt tiles off roofs in our
neighborhood
> a few weeks ago; they're still cleaning up. It's a lump of cold dense air
> that may have been rain at some point, thousands of meters up there in the
> clouds, but "evaporated" on the way down and fell on you! (Ours was full
of
> dust, too!)
> ----- Original Message -----
> From: "Bill N" <freeholder@STARBAND.NET>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Monday, August 12, 2002 12:44 PM
> Subject: Trip got interesting
>
>
> We were camping on Mt. Graham in SE Arizona this weekend when a very
unusual
> event occured.  There were 9 of us sitting around the campfire around 4 in
> the afternoon on Saturday.  It was partly cloudy and calm.  Within a 30
> second period it went from calm to winds I would estimate at 70+ MPH, and
> there was no warning.  We ran for our '81 Westy, and others ran for their
> vehicles.  We heard trees cracking all around us.
>
> Five minutes later, it was back to partly cloudy and calm.  There was no
> rain associated with this, and the whole thing lasted a very short time.
We
> hiked around taking stock and found that seven large ponderosa pines (2'
or
> larger trunk) had blown down within 100' or our campfire, taking several
> smaller trees with them.
>
> Although the poptop was up, and the sliding door was open the whole time,
> the van had no problems.  The wind direction was from the rear, which I'm
> sure helped.
>
> Any weather experts out there have any idea what causes this sort of
thing?
> I am told by neighbors that a similar wall of wind blew through my home
area
> (about 40 miles away) that same afternoon.
>
> Bill in the Southwest
>