[Met_help] [rt.rap.ucar.edu #88155] History for Climo WInds

[John Halley Gotway via RT]

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  Initial Request
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John, I have a question which I didn't see an answer in the user guide.  I am setting up grid stat to verify wind speed.  The model wind speeds are probabilities of wind speeds above a certain amount.  The climo data I have is the NCEP_2.5deg climo fields.  It contains mean values for u and v wind components broken out by month for 0, 6, 12, and 18z initialization times.  Since my model data is wind speeds, not u,v components, is there a way I can set the climo field parameters to retrieve both components so I can combine them into windspeed? Or does MET have logic to calculate wind speeds from wind components.  Attached is my current config file.  I also attached the climo file renamed to a .txt file.  It really is a grib 1 file.

Thanks
Bob


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  Complete Ticket History
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Subject: Climo WInds
From: John Halley Gotway
Time: Fri Dec 14 09:42:46 2018

Bob,

Yes, Grid-Stat (and all the other MET tools) automatically derive wind
speed on the fly from the U and V components.  This is not typical
behavior... wind speed is a special case and it only applies when
reading
GRIB 1 or 2 data.  To demonstrate, I used the pgba file you sent and
ran
the following plot_data_plane command

*/usr/local/met-6.1/bin/plot_data_plane pgba_mean.19591115 WIND_Z10.ps
'name="WIND"; level="Z10";' -v 3 -log run_plot_data_plane.log*

I attached the resulting log file and PNG version of the image.  In
the log
you'll find messages telling you that MET is deriving WIND speed from
U and
V.

I notice in your Grid-Stat config file that you're calling it "GUST"
instead of "WIND".  MET knows how to derive WIND from the UGRD and
VGRD
components, but doesn't have any special logic for "GUST".

I don't have your full set of data to test and make sure there aren't
any
wrinkles in using having U and V be derived from the climo field.
However,
I did modify an existing unit test for Grid-Stat by adding the
verification
of the probability of winds > 12.89, deriving wind speed from
climatology
data, and it all worked fine as expected.  I've also attached that
example
Grid-Stat config file (GridStatConfig_climo_prob).

FYI, I'll be out of the office until January.  But if you have
additional
questions, all of the other MET support staff will see your emails on
this
ticket.

Thanks,
John

On Thu, Dec 13, 2018 at 3:32 PM robert.craig.2 at us.af.mil via RT <
met_help at ucar.edu> wrote:

>
> Thu Dec 13 15:32:07 2018: Request 88155 was acted upon.
> Transaction: Ticket created by robert.craig.2 at us.af.mil
>        Queue: met_help
>      Subject: Climo WInds
>        Owner: Nobody
>   Requestors: robert.craig.2 at us.af.mil
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=88155 >
>
>
> John, I have a question which I didn't see an answer in the user
guide.  I
> am setting up grid stat to verify wind speed.  The model wind speeds
are
> probabilities of wind speeds above a certain amount.  The climo data
I have
> is the NCEP_2.5deg climo fields.  It contains mean values for u and
v wind
> components broken out by month for 0, 6, 12, and 18z initialization
times.
> Since my model data is wind speeds, not u,v components, is there a
way I
> can set the climo field parameters to retrieve both components so I
can
> combine them into windspeed? Or does MET have logic to calculate
wind
> speeds from wind components.  Attached is my current config file.  I
also
> attached the climo file renamed to a .txt file.  It really is a grib
1 file.
>
> Thanks
> Bob
>
>

------------------------------------------------
Subject: RE: [Non-DoD Source] Re: [rt.rap.ucar.edu #88155] Climo WInds
From: robert.craig.2 at us.af.mil
Time: Fri Dec 14 15:28:48 2018

Thanks John, have a great time away from  work.

Bob

-----Original Message-----
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Friday, December 14, 2018 10:43 AM
To: CRAIG, ROBERT J GS-12 USAF ACC 16 WS/WXN
<robert.craig.2 at us.af.mil>
Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #88155] Climo WInds

Bob,

Yes, Grid-Stat (and all the other MET tools) automatically derive wind
speed on the fly from the U and V components.  This is not typical
behavior... wind speed is a special case and it only applies when
reading GRIB 1 or 2 data.  To demonstrate, I used the pgba file you
sent and ran the following plot_data_plane command

*/usr/local/met-6.1/bin/plot_data_plane pgba_mean.19591115 WIND_Z10.ps
'name="WIND"; level="Z10";' -v 3 -log run_plot_data_plane.log*

I attached the resulting log file and PNG version of the image.  In
the log you'll find messages telling you that MET is deriving WIND
speed from U and V.

I notice in your Grid-Stat config file that you're calling it "GUST"
instead of "WIND".  MET knows how to derive WIND from the UGRD and
VGRD components, but doesn't have any special logic for "GUST".

I don't have your full set of data to test and make sure there aren't
any wrinkles in using having U and V be derived from the climo field.
However, I did modify an existing unit test for Grid-Stat by adding
the verification of the probability of winds > 12.89, deriving wind
speed from climatology data, and it all worked fine as expected.  I've
also attached that example Grid-Stat config file
(GridStatConfig_climo_prob).

FYI, I'll be out of the office until January.  But if you have
additional questions, all of the other MET support staff will see your
emails on this ticket.

Thanks,
John

On Thu, Dec 13, 2018 at 3:32 PM robert.craig.2 at us.af.mil via RT <
met_help at ucar.edu> wrote:

>
> Thu Dec 13 15:32:07 2018: Request 88155 was acted upon.
> Transaction: Ticket created by robert.craig.2 at us.af.mil
>        Queue: met_help
>      Subject: Climo WInds
>        Owner: Nobody
>   Requestors: robert.craig.2 at us.af.mil
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=88155
> >
>
>
> John, I have a question which I didn't see an answer in the user
> guide.  I am setting up grid stat to verify wind speed.  The model
> wind speeds are probabilities of wind speeds above a certain amount.
> The climo data I have is the NCEP_2.5deg climo fields.  It contains
> mean values for u and v wind components broken out by month for 0,
6, 12, and 18z initialization times.
> Since my model data is wind speeds, not u,v components, is there a
way
> I can set the climo field parameters to retrieve both components so
I
> can combine them into windspeed? Or does MET have logic to calculate
> wind speeds from wind components.  Attached is my current config
file.
> I also attached the climo file renamed to a .txt file.  It really is
a grib 1 file.
>
> Thanks
> Bob
>
>



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