[Antennas] WindDamage Statistics-FYI

[Tom]

Just call you local television station and ask for the weather department, 
or your local commercial or public airport, and they will tell you the 
stats for your area.  At least they do here in the Fort Worth, TX area.

There are lots of sites on the web with wind data for the entire 
world.  Just do a search or look at www.noaa.gov for starters.

The difference between a rare occurrence and a typical storm wind is not 
that much, so go for the extreme high wind.  Here in North Central Texas we 
get lots of wind and the farther west you go the more wind you get.  Ice 
and wind go together here all the time because of our proximity to the Gulf 
of Mexico.  A cold front will be topped out by a southerly wind which pumps 
lots of warm moisture into the air above the cold layer next to the ground, 
which then condenses out and causes superchilled water to accumulate and 
freeze when it hits the ground, or anything else, resulting in a ice 
storm.  Happens about twice a year here.

Tom F
KD5TIE

At 04:34 PM 9/9/2002, W3HKK@aol.com said something like:
>The info is proprietary and appears in the  FM Data Sheets, compiled by the
>largest insurer of   high protected risk (HPR) properties worldwide, Factory
>Mutual. .  Some libraries have  a set of these data sheets which fill 5 or 6
>large   three ring binders.
>
>Local building codes usually adopt and follow  NFPA Standards, which often do
>not cover industrial conditions as well as FM standards, which were created
>specifically for this reason.
>
>Winds are funny and hard to predict, as your experience proves.  Usually,
>major  ice buildup  forms in still air during a prolonged mist or drizzle
>when ground air is near the freezing point.   But at times these conditions
>can be closely  followed by windy conditions though rarely  high end winds.
>In my lifetime, in the northeast, Ive never seen  any substantial wind
>associated with an ice storm, however geographical and topographical
>conditions create all kinds of different  unique situations.  Standards are
>always concensus vehicles that try to  satisfy everyone.  This is of course
>impossible. Hence conservative design is of value, especially when the value
>of that being protected  is high.
>
>I have not lived in an area especially prone to ice storms but have seen some
>doozies.  Of course, over a long enough period,  everything happens...eg the
>disastrous power outages in Quebec a few years ago due to  a rare  ice storm,
>estimated to be of 500 year  interval.  Or the Cat 5 hurricane that hit the
>Miami area.
>
>Most  local codes use a minimum recommended wind design   of 50 - 100 year
>frequency ( once every....) often due to a lack of better data.
>
>Bob
>- - -
>
>Your moderator for this list is:
>Larry Wilson KE1HZ antennas-owner@mailman.qth.net
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