[Met_help] [rt.rap.ucar.edu #74115] History for Verification for hydrological catchments

[John Halley Gotway via RT]

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  Initial Request
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Hi,

We are interested in doing a verification of precipitation forecasts after
regridding the forecast and observational data to hydrological catchments
(the same catchments for both forecasts and observations).  From looking
briefly at the MET documentation, it looks like the forecasts must be on a
typical lat/lon grid for the software to work.  Am I understanding this
correctly?  Is there any way to use the software to calculate verification
statistics on forecasts / observations that are for catchments instead of a
lat / lon grid?

Thanks,
Emily


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  Complete Ticket History
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Subject: Verification for hydrological catchments
From: John Halley Gotway
Time: Mon Nov 16 09:53:53 2015

Hello Emily,

I see that you're considering applying the MET software to hydrologic
forecasts.  You're correct in thinking that MET is primarily used to
evaluate gridded forecast data.  And that gridded forecast data needs
to
defined on a regular grid... on a Lat/Lon, Polar Stereographic,
Lambert
Conformal, or Mercator projection.

I understand what a catchment is and I read that you have gridded
forecast
and observation fields, but I don't really understand what you mean by
computing statistics on catchments rather than grids.

Perhaps your are creating single forecast and observed accumulation
amounts
over the catchment and want to evaluate that as a point forecast
rather
than at individual grid points?  MET isn't really designed to handle
point
forecasts well, but I could show you a way to reformat your data for
use by
the STAT-Analysis tool.

In the absence of more details, my initial suggestion would be to
configure/run the Grid-Stat tool using many different masking
regions...
one for each catchment.  Then you could compute statistics for each
catchment separately.

If you send me a more detailed description of your datasets and how
you'd
like to process them, I could suggest which MET tools/options might be
helpful.  Alternatively, I see you're at NCAR/HAP.  I sit in FL3-1018,
and
you're welcome to drop by to talk more about it.

Thanks,
John Halley Gotway
met_help at ucar.edu



On Sat, Nov 14, 2015 at 10:28 AM, eriddle at ucar.edu via RT
<met_help at ucar.edu
> wrote:

>
> Sat Nov 14 10:28:52 2015: Request 74115 was acted upon.
> Transaction: Ticket created by eriddle at ucar.edu
>        Queue: met_help
>      Subject: Verification for hydrological catchments
>        Owner: Nobody
>   Requestors: eriddle at ucar.edu
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=74115 >
>
>
> Hi,
>
> We are interested in doing a verification of precipitation forecasts
after
> regridding the forecast and observational data to hydrological
catchments
> (the same catchments for both forecasts and observations).  From
looking
> briefly at the MET documentation, it looks like the forecasts must
be on a
> typical lat/lon grid for the software to work.  Am I understanding
this
> correctly?  Is there any way to use the software to calculate
verification
> statistics on forecasts / observations that are for catchments
instead of a
> lat / lon grid?
>
> Thanks,
> Emily
>
>

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Subject: Verification for hydrological catchments
From: eriddle at ucar.edu
Time: Mon Nov 16 15:05:39 2015

Hi John,

Thank you for the very helpful email.  Your understanding is correct
that
we are currently creating single forecast and observed accumulation
amounts
over the catchments and want to evaluate those as a point forecasts
(rather
than at individual grid points).  I think your suggestion of using
Grid-stat with different masking regions may be best, but it would be
nice
to talk.  I am a UCAR employee, but work remotely from Massachusetts,
so
perhaps a phone call tomorrow would be best.  Is there a time tomorrow
when
you will be available?  Anytime before 3 MT will work for me.

Thank you!

Emily

On Mon, Nov 16, 2015 at 11:53 AM, John Halley Gotway via RT <
met_help at ucar.edu> wrote:

> Hello Emily,
>
> I see that you're considering applying the MET software to
hydrologic
> forecasts.  You're correct in thinking that MET is primarily used to
> evaluate gridded forecast data.  And that gridded forecast data
needs to
> defined on a regular grid... on a Lat/Lon, Polar Stereographic,
Lambert
> Conformal, or Mercator projection.
>
> I understand what a catchment is and I read that you have gridded
forecast
> and observation fields, but I don't really understand what you mean
by
> computing statistics on catchments rather than grids.
>
> Perhaps your are creating single forecast and observed accumulation
amounts
> over the catchment and want to evaluate that as a point forecast
rather
> than at individual grid points?  MET isn't really designed to handle
point
> forecasts well, but I could show you a way to reformat your data for
use by
> the STAT-Analysis tool.
>
> In the absence of more details, my initial suggestion would be to
> configure/run the Grid-Stat tool using many different masking
regions...
> one for each catchment.  Then you could compute statistics for each
> catchment separately.
>
> If you send me a more detailed description of your datasets and how
you'd
> like to process them, I could suggest which MET tools/options might
be
> helpful.  Alternatively, I see you're at NCAR/HAP.  I sit in FL3-
1018, and
> you're welcome to drop by to talk more about it.
>
> Thanks,
> John Halley Gotway
> met_help at ucar.edu
>
>
>
> On Sat, Nov 14, 2015 at 10:28 AM, eriddle at ucar.edu via RT <
> met_help at ucar.edu
> > wrote:
>
> >
> > Sat Nov 14 10:28:52 2015: Request 74115 was acted upon.
> > Transaction: Ticket created by eriddle at ucar.edu
> >        Queue: met_help
> >      Subject: Verification for hydrological catchments
> >        Owner: Nobody
> >   Requestors: eriddle at ucar.edu
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=74115 >
> >
> >
> > Hi,
> >
> > We are interested in doing a verification of precipitation
forecasts
> after
> > regridding the forecast and observational data to hydrological
catchments
> > (the same catchments for both forecasts and observations).  From
looking
> > briefly at the MET documentation, it looks like the forecasts must
be on
> a
> > typical lat/lon grid for the software to work.  Am I understanding
this
> > correctly?  Is there any way to use the software to calculate
> verification
> > statistics on forecasts / observations that are for catchments
instead
> of a
> > lat / lon grid?
> >
> > Thanks,
> > Emily
> >
> >
>
>

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