Re: Call of the Wind reports - Coyote vs 3rd

From: Chris Kogelnik (kogelnik@interval.com-DeleteThis)
Date: Wed Sep 16 1998 - 12:51:09 PDT


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Date: Wed, 16 Sep 1998 12:51:09 -0700
To: wind_talk@opus.hpl.hp.com-DeleteThis
From: Chris Kogelnik <kogelnik@interval.com-DeleteThis>
Subject: Re: Call of the Wind reports - Coyote vs 3rd


> I have especially noticed this recently as there have been days in which
> Coyote has been reporting around 20 and I go to third and it basically
> stinks. I also remember a little while back Mike Godsey having a
> backcast to explain why Coyote seemed to report wind and he basically
> said: "I looked at all my charts and I'm convinced, there was no wind at
> Coyote." Having seen the wind that day I concurred. It's making me
> really cautious to use Coyote as the barometer for the wind. I'm
> usually ending up using Coyote, Third and SFO from good old Ken P.

The wind at Coyote probably wasn't at 20 either.

The wind flow at 3rd is usually outside in the channel. For example,
yesterday I sailed almost exclusively on the east side of the barges almost
the whole time, fully powered. On the west side of the barges it was marginal.
There is no way a sensor on the beach at 3rd is going to give accurate
adjustments for on the water conditions 1+ miles away without getting
additional data from some other site. The wind direction was also different
on the east side than on the west side.

So just looking at the Coyote wind strength is not a good indication of
if 3rd will be good, since the Coyote sensor needs to do the same estimation
and may not be accurate in its prediction.

I think this problem can be most easily resolved by COTW releasing it's
sensor adjustments. They promised it would be available "in a few days"
almost 3 months ago, and I asked for it a year and half ago.

I've been skunked by the pager readings so many times now that I don't
trust them for certain wind directions, when I would bet the raw wind
data would indicate significantly lower wind than reported. So additionally,
COTW should *NOT* try to adjust sensor readings for directions that haven't
been correlated or are known to be troublesome.

It's still hard to ignore a Crissy pager reading of 20 if you haven't sailed
in a week, only to make the drive and find out it's more like 13. I think
it's more acceptable to miss a day of sailing due the pager not showing a
high reading for some flukely wind direction, than for it to report a high
reading for conditions that don't exist, IMHO (that's what on-site reports are
for). That way, if the pager says it's going off, you know it's going off.

Chris



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