[Met_help] [rt.rap.ucar.edu #51067] History for Forecast with missing values
John Halley Gotway via RT
met_help at ucar.edu
Tue Dec 13 09:07:34 MST 2011
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Initial Request
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Dear MET team,
I would like to use the point_stat tool with a forecast which contains missing values. Sadly point_stat makes use of the missing values to match observations. This is an example of an MPR line where point_stat makes use of missing values:
point_stat_300000L_20060812_180000V.stat:V3.0.1 WRF 300000 20060812_180000 20060812_180000 000000 20060812_173606 20060812_173606 WIND P1000-800 WIND P1000-800 ADPUPA FULL UW_MEAN 1 NA NA NA NA MPR 39 1 65125 9.25000 7.00000 970.00000 393.29999 -5023.81181 2.04000 NA
Are missing values in forecast files not allowed?
Is only a special missing values allowed?
Thanks,
Robert
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Complete Ticket History
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Subject: Re: [rt.rap.ucar.edu #51067] Forecast with missing values
From: John Halley Gotway
Time: Mon Oct 31 09:50:39 2011
Robert,
I suspect that you're passing Point-Stat a NetCDF file as the gridded
data file. Yes, missing values are allowed, but unfortunately, your
second question is correct - only "-9999" is interpreted as a
missing value. Our development plans do include better support for
the NetCDF CF-convention - at which point, we'll extract/use the
missing data value specified in the NetCDF variable attribute.
Sorry for the trouble but using a missing value of "-9999" should do
the trick from METv3.0.1.
Thanks,
John Halley Gotway
On 10/30/2011 12:38 PM, Robert Schuster via RT wrote:
>
> Sun Oct 30 12:38:45 2011: Request 51067 was acted upon.
> Transaction: Ticket created by rxschuster at googlemail.com
> Queue: met_help
> Subject: Forecast with missing values
> Owner: Nobody
> Requestors: rxschuster at googlemail.com
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=51067 >
>
>
> Dear MET team,
>
> I would like to use the point_stat tool with a forecast which
contains missing values. Sadly point_stat makes use of the missing
values to match observations. This is an example of an MPR line where
point_stat makes use of missing values:
>
> point_stat_300000L_20060812_180000V.stat:V3.0.1 WRF 300000
20060812_180000 20060812_180000 000000 20060812_173606
20060812_173606 WIND P1000-800 WIND P1000-800 ADPUPA FULL
UW_MEAN 1 NA NA NA NA MPR
39 1 65125 9.25000 7.00000 970.00000 393.29999
-5023.81181 2.04000 NA
>
> Are missing values in forecast files not allowed?
> Is only a special missing values allowed?
>
> Thanks,
> Robert
>
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Subject: Re: [rt.rap.ucar.edu #51067] Forecast with missing values
From: Robert Schuster
Time: Tue Nov 01 03:38:28 2011
Thank you for the answer.
I'm using grib-Files created with NCL and CDO. The missing values are
the NCL defaults. I will change that to -9999. Or is there any other
problem with missing values in grib-Files?
Robert
Am 31.10.2011 um 16:50 schrieb John Halley Gotway via RT:
> Robert,
>
> I suspect that you're passing Point-Stat a NetCDF file as the
gridded data file. Yes, missing values are allowed, but
unfortunately, your second question is correct - only "-9999" is
interpreted as a
> missing value. Our development plans do include better support for
the NetCDF CF-convention - at which point, we'll extract/use the
missing data value specified in the NetCDF variable attribute.
>
> Sorry for the trouble but using a missing value of "-9999" should do
the trick from METv3.0.1.
>
> Thanks,
> John Halley Gotway
>
> On 10/30/2011 12:38 PM, Robert Schuster via RT wrote:
>>
>> Sun Oct 30 12:38:45 2011: Request 51067 was acted upon.
>> Transaction: Ticket created by rxschuster at googlemail.com
>> Queue: met_help
>> Subject: Forecast with missing values
>> Owner: Nobody
>> Requestors: rxschuster at googlemail.com
>> Status: new
>> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=51067 >
>>
>>
>> Dear MET team,
>>
>> I would like to use the point_stat tool with a forecast which
contains missing values. Sadly point_stat makes use of the missing
values to match observations. This is an example of an MPR line where
point_stat makes use of missing values:
>>
>> point_stat_300000L_20060812_180000V.stat:V3.0.1 WRF 300000
20060812_180000 20060812_180000 000000 20060812_173606
20060812_173606 WIND P1000-800 WIND P1000-800 ADPUPA FULL
UW_MEAN 1 NA NA NA NA MPR
39 1 65125 9.25000 7.00000 970.00000 393.29999
-5023.81181 2.04000 NA
>>
>> Are missing values in forecast files not allowed?
>> Is only a special missing values allowed?
>>
>> Thanks,
>> Robert
>>
>
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Subject: Re: [rt.rap.ucar.edu #51067] Forecast with missing values
From: John Halley Gotway
Time: Tue Nov 01 09:33:44 2011
Robert,
Hmmm, I've never used GRIB files generated with NCL and CDO. When it
come to specifying missing values in GRIB, I've typically seen the use
of the bitmap section (BMS). The BMS contains a bunch of
0's and 1's. It's set to 0 where the data is missing and 1 where
there's good data. GRIB records can have a BMS but do not have to.
If it is present, then the MET tools will parse it and use it.
However, I think that using a missing value of -9999 in your GRIB file
should be fine. I can't say for certain but it's worth a try.
If you do get it working well and would be willing to send us an
example of the commands you used to generate that GRIB file, we'd
really appreciate it.
Thanks and just let us know if more issues arise.
John
On 11/01/2011 03:38 AM, Robert Schuster via RT wrote:
> I'm using grib-Files created with NCL and CDO. The missing values
are the NCL defaults. I will change that to -9999. Or is there any
other problem with missing values in grib-Files?
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