[Met_help] [rt.rap.ucar.edu #83540] History for how to set wind speed threshold in Ensemble_stat mode

John Halley Gotway via RT met_help at ucar.edu
Tue Jan 16 09:32:14 MST 2018


----------------------------------------------------------------
  Initial Request
----------------------------------------------------------------

Hi all,

     I have a question about the setting of wind speed threshold,  since in Point_stat mode: we can set wind speed threshold as

wind_thresh = [ >1.6,>=1.6&&<3.4 ];
wind_logic  = UNION;

 and find the results in Vl1l2.

But in ensemble_stat, how to set wind set threshold? Can I add the this option just before

//
// Ensemble product fields to be processed
//

wind_thresh = [ >1.6,>=1.6&&<3.4 ];
wind_logic  = UNION;

ens = {
   ens_thresh = 1.0;
   vld_thresh = 1.0;


   field = [
 {
        name       = "TMP";
        level      =  "Z10" ;
        cat_thresh = [ >=273,>=293,>=308,>=413 ];
      },

Thank you very much!

Mandy


----------------------------------------------------------------
  Complete Ticket History
----------------------------------------------------------------

Subject: how to set wind speed threshold in Ensemble_stat mode
From: John Halley Gotway
Time: Wed Jan 10 10:33:18 2018

Mandy,

The "wind_thresh" setting is used to filter the U/V pairs which are
included in the computation of the VL1L2 output line type.  This line
type
is produced by both the Point-Stat and Grid-Stat tools, and that's why
"wind_thresh" shows up in those tools.

The Ensemble-Stat tool does not produce the VL1L2 output line type,
and so
"wind_thresh" is not a configurable option there.

However, Ensemble-Stat does include somewhat similar options in met-
6.1:
  - censor_thresh and censor_val are used to modify raw input values
followed the rules defined
  - obs_thresh is very similar to the wind_thresh setting.  Any
observation
points that don't meet this threshold criteria will be excluded from
the
verification.

If you can describe exactly what you'd like to do, I can provide
better
info on whether MET can currently do it.

Thanks,
John Halley Gotway



On Wed, Jan 10, 2018 at 10:24 AM, Zhang, Mandy via RT
<met_help at ucar.edu>
wrote:

>
> Wed Jan 10 10:24:08 2018: Request 83540 was acted upon.
> Transaction: Ticket created by Man.Zhang-1 at ou.edu
>        Queue: met_help
>      Subject: how to set wind speed threshold in Ensemble_stat mode
>        Owner: Nobody
>   Requestors: Man.Zhang-1 at ou.edu
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
>
>
> Hi all,
>
>      I have a question about the setting of wind speed threshold,
since
> in Point_stat mode: we can set wind speed threshold as
>
> wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> wind_logic  = UNION;
>
>  and find the results in Vl1l2.
>
> But in ensemble_stat, how to set wind set threshold? Can I add the
this
> option just before
>
> //
> // Ensemble product fields to be processed
> //
>
> wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> wind_logic  = UNION;
>
> ens = {
>    ens_thresh = 1.0;
>    vld_thresh = 1.0;
>
>
>    field = [
>  {
>         name       = "TMP";
>         level      =  "Z10" ;
>         cat_thresh = [ >=273,>=293,>=308,>=413 ];
>       },
>
> Thank you very much!
>
> Mandy
>
>

------------------------------------------------
Subject: how to set wind speed threshold in Ensemble_stat mode
From: Zhang, Mandy
Time: Wed Jan 10 13:39:14 2018

Hi John,

    Thank you for replying.

     I want to verify wind speed from the ensemble forecasts against
observation, since I have to get the probability results from the
ensemble_stat first, then use this result to run point_stat, so I need
to define the wind threshold in the ensemble_stat.

   From your suggestion, I need to install the lastest met_version, so
Met can do ensemble verification of wind speed, is it right?

   Thank you!

Mandy

________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, January 10, 2018 11:33:19 AM
To: Zhang, Mandy
Subject: Re: [rt.rap.ucar.edu #83540] how to set wind speed threshold
in Ensemble_stat mode

Mandy,

The "wind_thresh" setting is used to filter the U/V pairs which are
included in the computation of the VL1L2 output line type.  This line
type
is produced by both the Point-Stat and Grid-Stat tools, and that's why
"wind_thresh" shows up in those tools.

The Ensemble-Stat tool does not produce the VL1L2 output line type,
and so
"wind_thresh" is not a configurable option there.

However, Ensemble-Stat does include somewhat similar options in met-
6.1:
  - censor_thresh and censor_val are used to modify raw input values
followed the rules defined
  - obs_thresh is very similar to the wind_thresh setting.  Any
observation
points that don't meet this threshold criteria will be excluded from
the
verification.

If you can describe exactly what you'd like to do, I can provide
better
info on whether MET can currently do it.

Thanks,
John Halley Gotway



On Wed, Jan 10, 2018 at 10:24 AM, Zhang, Mandy via RT
<met_help at ucar.edu>
wrote:

>
> Wed Jan 10 10:24:08 2018: Request 83540 was acted upon.
> Transaction: Ticket created by Man.Zhang-1 at ou.edu
>        Queue: met_help
>      Subject: how to set wind speed threshold in Ensemble_stat mode
>        Owner: Nobody
>   Requestors: Man.Zhang-1 at ou.edu
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
>
>
> Hi all,
>
>      I have a question about the setting of wind speed threshold,
since
> in Point_stat mode: we can set wind speed threshold as
>
> wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> wind_logic  = UNION;
>
>  and find the results in Vl1l2.
>
> But in ensemble_stat, how to set wind set threshold? Can I add the
this
> option just before
>
> //
> // Ensemble product fields to be processed
> //
>
> wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> wind_logic  = UNION;
>
> ens = {
>    ens_thresh = 1.0;
>    vld_thresh = 1.0;
>
>
>    field = [
>  {
>         name       = "TMP";
>         level      =  "Z10" ;
>         cat_thresh = [ >=273,>=293,>=308,>=413 ];
>       },
>
> Thank you very much!
>
> Mandy
>
>


------------------------------------------------
Subject: how to set wind speed threshold in Ensemble_stat mode
From: John Halley Gotway
Time: Wed Jan 10 16:38:20 2018

Mandy,

It sounds like you'd like to use ensemble_stat to compute ensemble
relative
frequencies (i.e. probabilities) for wind speed.  I assume you're
passing
GRIB1 or GRIB2 input file into ensembe_stat.  All you need to do is
request
WIND speed from those files.

WIND speed is a special case in MET.  If it's not present in the input
GRIB1/2 files, MET finds the corresponding U and V components and
derives
WIND speed on the fly.

Let's say you want to compute the probabilities of 10-m wind speed
exceeding 5 m/s and 7 m/s, you'd do that like this:

ens = {

   field = [

      {

         name       = "WIND";

         level      = "Z10";

         cat_thresh = [ >=5.0, >=7.0 ];

      }

   ];

}


Hopefully that helps.


Thanks,
John

On Wed, Jan 10, 2018 at 1:39 PM, Zhang, Mandy via RT
<met_help at ucar.edu>
wrote:

>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
>
> Hi John,
>
>     Thank you for replying.
>
>      I want to verify wind speed from the ensemble forecasts against
> observation, since I have to get the probability results from the
> ensemble_stat first, then use this result to run point_stat, so I
need to
> define the wind threshold in the ensemble_stat.
>
>    From your suggestion, I need to install the lastest met_version,
so Met
> can do ensemble verification of wind speed, is it right?
>
>    Thank you!
>
> Mandy
>
> ________________________________
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Wednesday, January 10, 2018 11:33:19 AM
> To: Zhang, Mandy
> Subject: Re: [rt.rap.ucar.edu #83540] how to set wind speed
threshold in
> Ensemble_stat mode
>
> Mandy,
>
> The "wind_thresh" setting is used to filter the U/V pairs which are
> included in the computation of the VL1L2 output line type.  This
line type
> is produced by both the Point-Stat and Grid-Stat tools, and that's
why
> "wind_thresh" shows up in those tools.
>
> The Ensemble-Stat tool does not produce the VL1L2 output line type,
and so
> "wind_thresh" is not a configurable option there.
>
> However, Ensemble-Stat does include somewhat similar options in met-
6.1:
>   - censor_thresh and censor_val are used to modify raw input values
> followed the rules defined
>   - obs_thresh is very similar to the wind_thresh setting.  Any
observation
> points that don't meet this threshold criteria will be excluded from
the
> verification.
>
> If you can describe exactly what you'd like to do, I can provide
better
> info on whether MET can currently do it.
>
> Thanks,
> John Halley Gotway
>
>
>
> On Wed, Jan 10, 2018 at 10:24 AM, Zhang, Mandy via RT
<met_help at ucar.edu>
> wrote:
>
> >
> > Wed Jan 10 10:24:08 2018: Request 83540 was acted upon.
> > Transaction: Ticket created by Man.Zhang-1 at ou.edu
> >        Queue: met_help
> >      Subject: how to set wind speed threshold in Ensemble_stat
mode
> >        Owner: Nobody
> >   Requestors: Man.Zhang-1 at ou.edu
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
> >
> >
> > Hi all,
> >
> >      I have a question about the setting of wind speed threshold,
since
> > in Point_stat mode: we can set wind speed threshold as
> >
> > wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> > wind_logic  = UNION;
> >
> >  and find the results in Vl1l2.
> >
> > But in ensemble_stat, how to set wind set threshold? Can I add the
this
> > option just before
> >
> > //
> > // Ensemble product fields to be processed
> > //
> >
> > wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> > wind_logic  = UNION;
> >
> > ens = {
> >    ens_thresh = 1.0;
> >    vld_thresh = 1.0;
> >
> >
> >    field = [
> >  {
> >         name       = "TMP";
> >         level      =  "Z10" ;
> >         cat_thresh = [ >=273,>=293,>=308,>=413 ];
> >       },
> >
> > Thank you very much!
> >
> > Mandy
> >
> >
>
>
>

------------------------------------------------
Subject: how to set wind speed threshold in Ensemble_stat mode
From: Zhang, Mandy
Time: Fri Jan 12 08:57:43 2018

Thank you John,

It works!

Mandy

________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, January 10, 2018 5:38:20 PM
To: Zhang, Mandy
Subject: Re: [rt.rap.ucar.edu #83540] how to set wind speed threshold
in Ensemble_stat mode

Mandy,

It sounds like you'd like to use ensemble_stat to compute ensemble
relative
frequencies (i.e. probabilities) for wind speed.  I assume you're
passing
GRIB1 or GRIB2 input file into ensembe_stat.  All you need to do is
request
WIND speed from those files.

WIND speed is a special case in MET.  If it's not present in the input
GRIB1/2 files, MET finds the corresponding U and V components and
derives
WIND speed on the fly.

Let's say you want to compute the probabilities of 10-m wind speed
exceeding 5 m/s and 7 m/s, you'd do that like this:

ens = {

   field = [

      {

         name       = "WIND";

         level      = "Z10";

         cat_thresh = [ >=5.0, >=7.0 ];

      }

   ];

}


Hopefully that helps.


Thanks,
John

On Wed, Jan 10, 2018 at 1:39 PM, Zhang, Mandy via RT
<met_help at ucar.edu>
wrote:

>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
>
> Hi John,
>
>     Thank you for replying.
>
>      I want to verify wind speed from the ensemble forecasts against
> observation, since I have to get the probability results from the
> ensemble_stat first, then use this result to run point_stat, so I
need to
> define the wind threshold in the ensemble_stat.
>
>    From your suggestion, I need to install the lastest met_version,
so Met
> can do ensemble verification of wind speed, is it right?
>
>    Thank you!
>
> Mandy
>
> ________________________________
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Wednesday, January 10, 2018 11:33:19 AM
> To: Zhang, Mandy
> Subject: Re: [rt.rap.ucar.edu #83540] how to set wind speed
threshold in
> Ensemble_stat mode
>
> Mandy,
>
> The "wind_thresh" setting is used to filter the U/V pairs which are
> included in the computation of the VL1L2 output line type.  This
line type
> is produced by both the Point-Stat and Grid-Stat tools, and that's
why
> "wind_thresh" shows up in those tools.
>
> The Ensemble-Stat tool does not produce the VL1L2 output line type,
and so
> "wind_thresh" is not a configurable option there.
>
> However, Ensemble-Stat does include somewhat similar options in met-
6.1:
>   - censor_thresh and censor_val are used to modify raw input values
> followed the rules defined
>   - obs_thresh is very similar to the wind_thresh setting.  Any
observation
> points that don't meet this threshold criteria will be excluded from
the
> verification.
>
> If you can describe exactly what you'd like to do, I can provide
better
> info on whether MET can currently do it.
>
> Thanks,
> John Halley Gotway
>
>
>
> On Wed, Jan 10, 2018 at 10:24 AM, Zhang, Mandy via RT
<met_help at ucar.edu>
> wrote:
>
> >
> > Wed Jan 10 10:24:08 2018: Request 83540 was acted upon.
> > Transaction: Ticket created by Man.Zhang-1 at ou.edu
> >        Queue: met_help
> >      Subject: how to set wind speed threshold in Ensemble_stat
mode
> >        Owner: Nobody
> >   Requestors: Man.Zhang-1 at ou.edu
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=83540 >
> >
> >
> > Hi all,
> >
> >      I have a question about the setting of wind speed threshold,
since
> > in Point_stat mode: we can set wind speed threshold as
> >
> > wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> > wind_logic  = UNION;
> >
> >  and find the results in Vl1l2.
> >
> > But in ensemble_stat, how to set wind set threshold? Can I add the
this
> > option just before
> >
> > //
> > // Ensemble product fields to be processed
> > //
> >
> > wind_thresh = [ >1.6,>=1.6&&<3.4 ];
> > wind_logic  = UNION;
> >
> > ens = {
> >    ens_thresh = 1.0;
> >    vld_thresh = 1.0;
> >
> >
> >    field = [
> >  {
> >         name       = "TMP";
> >         level      =  "Z10" ;
> >         cat_thresh = [ >=273,>=293,>=308,>=413 ];
> >       },
> >
> > Thank you very much!
> >
> > Mandy
> >
> >
>
>
>


------------------------------------------------


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