[Met_help] [rt.rap.ucar.edu #46697] History for wind direction (point-stat?)

[RAL HelpDesk {for John Halley Gotway}]

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  Initial Request
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Hi,
I'm trying to verify some wind speed an direction forecasts, using observed
(surface) windspeeds.
The forecasts contain windspeed and the U and V components (and hence
direction can be derived). However, the observations only contain a
windspeed and wind direction (degrees).
When I try running point-stat for wind direction I get:
"wind direction field may not be verified using point_stat"

I understand (from the tutorial and web pages etc) that wind direction can
be verified using STAT-Analysis (with VL1L2 from the point-stat tool, which
is run on the U and V winds). However, my obs don't have a U and V
windspeeds, so is it not possible to verify the wind direction?

Of course it would be possible to convert the observed windspeed into U and
V components (with knowledge of the wind direction), and then run point-sta
and STAT-Analysis on those, but I was wondering if there was another way
around?
Thanks,
Jason


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  Complete Ticket History
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Subject: Re: [rt.rap.ucar.edu #46697] wind direction (point-stat?)
From: John Halley Gotway
Time: Wed May 04 21:51:14 2011

Jason,

Unfortunately, no, there is currently no way in MET for you to compare
forecast wind directions directly to observed wind directions.  You're
correct, that you could back out the U and V values from the wind
speed
and direction in your observations, but I do see why that's not very
desirable.

I do think our support for verifying wind direction is a little
lacking,
but we've had trouble defining what statistics are most appropriate
for
wind direction.

Thanks,
John Halley Gotway
met_help at ucar.edu

>
> Wed May 04 17:11:38 2011: Request 46697 was acted upon.
> Transaction: Ticket created by marshj77 at gmail.com
>        Queue: met_help
>      Subject: wind direction (point-stat?)
>        Owner: Nobody
>   Requestors: marshj77 at gmail.com
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=46697 >
>
>
> Hi,
> I'm trying to verify some wind speed an direction forecasts, using
> observed
> (surface) windspeeds.
> The forecasts contain windspeed and the U and V components (and
hence
> direction can be derived). However, the observations only contain a
> windspeed and wind direction (degrees).
> When I try running point-stat for wind direction I get:
> "wind direction field may not be verified using point_stat"
>
> I understand (from the tutorial and web pages etc) that wind
direction can
> be verified using STAT-Analysis (with VL1L2 from the point-stat
tool,
> which
> is run on the U and V winds). However, my obs don't have a U and V
> windspeeds, so is it not possible to verify the wind direction?
>
> Of course it would be possible to convert the observed windspeed
into U
> and
> V components (with knowledge of the wind direction), and then run
> point-sta
> and STAT-Analysis on those, but I was wondering if there was another
way
> around?
> Thanks,
> Jason
>



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Subject: wind direction (point-stat?)
From: jason marsh
Time: Thu May 05 13:44:34 2011

Hi John,
Thanks for your response.
I'll maybe go down the route of splitting into U and V components
then.
Thanks for you continued support of MET.

Jason

On Wed, May 4, 2011 at 5:51 PM, RAL HelpDesk {for John Halley Gotway}
<
met_help at ucar.edu> wrote:

> Jason,
>
> Unfortunately, no, there is currently no way in MET for you to
compare
> forecast wind directions directly to observed wind directions.
You're
> correct, that you could back out the U and V values from the wind
speed
> and direction in your observations, but I do see why that's not very
> desirable.
>
> I do think our support for verifying wind direction is a little
lacking,
> but we've had trouble defining what statistics are most appropriate
for
> wind direction.
>
> Thanks,
> John Halley Gotway
> met_help at ucar.edu
>
> >
> > Wed May 04 17:11:38 2011: Request 46697 was acted upon.
> > Transaction: Ticket created by marshj77 at gmail.com
> >        Queue: met_help
> >      Subject: wind direction (point-stat?)
> >        Owner: Nobody
> >   Requestors: marshj77 at gmail.com
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=46697 >
> >
> >
> > Hi,
> > I'm trying to verify some wind speed an direction forecasts, using
> > observed
> > (surface) windspeeds.
> > The forecasts contain windspeed and the U and V components (and
hence
> > direction can be derived). However, the observations only contain
a
> > windspeed and wind direction (degrees).
> > When I try running point-stat for wind direction I get:
> > "wind direction field may not be verified using point_stat"
> >
> > I understand (from the tutorial and web pages etc) that wind
direction
> can
> > be verified using STAT-Analysis (with VL1L2 from the point-stat
tool,
> > which
> > is run on the U and V winds). However, my obs don't have a U and V
> > windspeeds, so is it not possible to verify the wind direction?
> >
> > Of course it would be possible to convert the observed windspeed
into U
> > and
> > V components (with knowledge of the wind direction), and then run
> > point-sta
> > and STAT-Analysis on those, but I was wondering if there was
another way
> > around?
> > Thanks,
> > Jason
> >
>
>
>
>

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