[Met_help] How to specify the surface variable in thepoint_stat?

Tue Jun 30 15:14:12 MDT 2009

Kefeng,

It's no problem at all.  I'm happy to help.

I ran your data exactly as you sent it through my version of METv2.0, and
it did not produce the segmentation fault you're seeing.

I noticed though that in the PointStatConfig file you sent, you're using
"TMP/Z0", but in the error message you sent it lists "TMP/L0".  When I
changed the config file to use "TMP/L0", I do see the segmentation fault
you're seeing.

I'll look into what's causing that seg-fault tomorrow.  In the meantime,
stick with using "TMP/Z0".  However, when using "TMP/Z0" you'll notice
that you get 0 matched pairs for MSONET.  The reason for that is how
matching is done in the vertical for surface variables which I explained
in a previous email.  I've cut-and-pasted that info below.

Thanks,
John

> Here's the scoop on matching to vertical levels in Point-Stat...
> Point-Stat doesn't even look at the height value for the observation
> points.  Instead, the matching for surface variables is done entirely by
> message type.  Any observations with a message type of ADPSFC or SFCSHP
> are considered to be at the surface and are matched to surface variables.
> So if you're verifying TMP/Z0, you should verify using observations with
> a
> message type of ADPSFC or SFCSHP.
> For this reason, in METv2.0 you won't be able to match MSONET
> observations
> to surface variables because the code doesn't consider the MSONET message
> type to be at the surface.
> I realize that this logic for matching in the veritical is rather
> simplistic.  We inherited it from some exisitng NCEP verification code,
> and decided not to alter it until it becomes necessary to do so.
> If this doesn't meet your needs, let me know.  And we can look for more
> sophsticated ways of matching in the vertical.  If that is needed, it'd
> be
> helpful for you to send us a sample forecast file, sample point
> observation file, and a description of how exactly you'd like them to be
> matched up in the vertical.

> Hi, John:
>
>     Sorry to bother you again and again. I start to do the point_stat
> analysis as you told me. I want to use the Oklahoma Mesonet data as
> truth. Using the parameter like "TMP/L0", but get segmentation fault.
>
> /work/01008/kfzhu/verification/METv2.0/bin/point_stat
> /work/01008/kfzhu/result/wpp/control/control_grib/wrfprs_d01.2007081907
> /work/01008/kfzhu/result/prebufr/pb2nc/pb2007081907.nc
> config/PointStatConfig_OKC -outdir
> /work/01008/kfzhu/result/metout/control/point_stat/ -v 2
> GSL_RNG_TYPE=mt19937
> GSL_RNG_SEED=3110750794
> Forecast File:
> /work/01008/kfzhu/result/wpp/control/control_grib/wrfprs_d01.2007081907
> Climatology File: none
> Configuration File: config/PointStatConfig_OKC
> Observation File: /work/01008/kfzhu/result/prebufr/pb2nc/pb2007081907.nc
> ----------------------------------------
> Reading records for TMP/L0.
> For TMP/L0 found 1 forecast levels and 0 climatology levels.
> ----------------------------------------
> Searching 229002 observations from 54900 PrepBufr messages.
> Segmentation fault
>
> Here is the link of the sampe data.
> http://www.caps.ou.edu/~kzhu/dataerin.tar.gz
> 20072310700.t07z.prebufr: orgrinal NCEP prepbufr data
> Oklahoma.poly: Masking area
> pb2007081907.nc : after data process of pb2nc using METv2.0
> PB2NCConfig_OKC: configure file of pb2nc
> PointStatConfig_OKC: configure file of point_stat
> wrfprs_d01.2007081907: the forecasted filed
>
> I have looked into the NETCDF file after pb2nc, and find that there're 171
> mesonet site in the Oklahoma region. The attachment show the site
> location. And the grib type of the data are 7,11,17,32,33,34,51,52,53.
> Could you help me to look into these data?
>
> Thank you!
>
> Kefeng
>
>
>
> 2009-06-30
>
>
>
> Zhu,Kefeng
>
>
>
> å‘ä»¶äººï¼š John Halley Gotway
> å‘é€æ—¶é—´ï¼š 2009-05-29  21:02:47
> æ”¶ä»¶äººï¼š Zhu, Kefeng
> æŠ„é€ï¼š met_help
> ä¸»é¢˜ï¼š Re: [Met_help] How to specify the surface variable in
> thepoint_stat?
>
> Kefeng,
> Sorry for the delay in getting back with you.
> Yes, specifying "TMP/Z0" should tell Point-Stat to retrieve the surface
> temperature variable.  If for some reason that doesn't work, try using
> "TMP/L0" instead.  The difference is that when you say Z0, Point-Stat
> tries to find a GRIB record that's defined as a VERTICAL level with a
> level value of 0.  When you say L0, Point-Stat tries to find a GRIB
> record
> with a level value of 0 regardless of what "type" of level it is:
> vertical
> level, pressure level, or any other type of level.  But "TMP/Z0" should
> do
> the trick.
> Here's the scoop on matching to vertical levels in Point-Stat...
> Point-Stat doesn't even look at the height value for the observation
> points.  Instead, the matching for surface variables is done entirely by
> message type.  Any observations with a message type of ADPSFC or SFCSHP
> are considered to be at the surface and are matched to surface variables.
> So if you're verifying TMP/Z0, you should verify using observations with
> a
> message type of ADPSFC or SFCSHP.
> For this reason, in METv2.0 you won't be able to match MSONET
> observations
> to surface variables because the code doesn't consider the MSONET message
> type to be at the surface.
> I realize that this logic for matching in the veritical is rather
> simplistic.  We inherited it from some exisitng NCEP verification code,
> and decided not to alter it until it becomes necessary to do so.
> If this doesn't meet your needs, let me know.  And we can look for more
> sophsticated ways of matching in the vertical.  If that is needed, it'd
> be
> helpful for you to send us a sample forecast file, sample point
> observation file, and a description of how exactly you'd like them to be
> matched up in the vertical.
> I'll be out of town all next week at a conference, so I won't have much
> time to respond until the following week.
> Thanks,
> John Halley Gotway
> johnhg at ucar.edu
>>
>> Hi:
>>
>>     I'm wondering how to specify the surface variable like surface
>> temperature? Does 'TMP/Z0' work? How does MET deal with the
>> observation when i specify 'TMP/Z0' while actually the observed
>> temperature are at 1.5m height?
>>      Another question is do MET have any detail instruction about what
>> kind of variable can be verified by specified type of observation
>> like MSONET?  Beacuse when i set the
>> fcst_field[] = [ "TMP/Z0", "UGRD/Z10", "VGRD/Z10" ];
>> message_type[] = [ "MSONET" ];
>>     I got nothing after the point_stat analysis.
>>     Thanks!
>>
>> Kefeng
>>
>> 2009-05-27
>>
>>
>>
>> Zhu,Kefeng
>> _______________________________________________
>> Met_help mailing list
>> Met_help at mailman.ucar.edu
>> http://mailman.ucar.edu/mailman/listinfo/met_help
>>
> .
>