Re: Problem reading NCEP RTMA grib2 files

From: David Brown <dbrown_at_nyahnyahspammersnyahnyah>
Date: Wed Mar 06 2013 - 13:27:00 MST

Yes, that is correct. At the moment NCL cannot find anything to distinguish these 2 records, and eliminates one of them as a "duplicate" record.
Of course the actual data is quite different.
I hope to modify the code to at least give two variables with the second one having an '_1' attached to it.
 -dave

On Mar 6, 2013, at 1:21 PM, Winston Hao wrote:

> Hi Gerry,
>
> I plotted the variable TMP_L103_GLC0 and found out it is
> the analysis uncertainty field. My guess is the 1st record, the
> temperature record, is treated as a duplicate record. But I am
> not sure.
>
> Winston
>
>
> Winston Hao
> New York State Dept of Environmental Conservation
> 625 Broadway, 9th Floor, Albany, NY 12233-3259
> whao@dec.state.ny.us (518)402-8384 (Work) (518)402-9035 (Fax)
>
> On Wed, 6 Mar 2013, Gerry Creager - NOAA Affiliate wrote:
>
>> I've not looked in depth but a quick pass with ncl_filedump shows a
>> variable TMP_P0_L103_GLC0 (Temperature, K), and grid-related variables for
>> rotation, lat and lon. Nothing for analysis uncertainty that I could find.
>>
>> gerry
>>
>>
>> On Wed, Mar 6, 2013 at 1:08 PM, David Brown <dbrown@ucar.edu> wrote:
>>
>>> Hi Winston,
>>>
>>> I will look into this. Thanks for the report.
>>> -dave
>>>
>>> On Mar 6, 2013, at 11:07 AM, Winston Hao wrote:
>>>
>>>> Hi All,
>>>>
>>>> I try to plot NCEP Real-Time Mesoscale Analysis (RTMA) hourly
>>>> 2-m temperature field using ncl, but I could not read those grib2 files
>>>> properly. I have uploaded an example file called
>>> LTIA98_KWBR_201107010000
>>>> to ftp.cgd.ucar.edu:/incoming The same file can be downloaded directly
>>>> from NCDC RTMA archive via wget. The link is
>>>>
>>> http://nomads.ncdc.noaa.gov/data/ndgd/201107/20110701/LTIA98_KWBR_201107010000
>>>> The file size is about 8 megabytes.
>>>>
>>>> The file should have two records, one for the temperature analysis
>>> and the
>>>> other for the analysis uncertainty. Wgrib2 utility confirms that:
>>>>
>>>> 1:0:d=2011070100:TMP:2 m above ground:anl:
>>>> 2:4799894:d=2011070100:TMP:2 m above ground:anl:analysis/forecast error
>>>>
>>>> However, in my ncl script, or from ncl_filedump, or from
>>> ncl_convert2nc,
>>>> I can only see one record, the 2nd record. My work-around is to use
>>> wgrib2
>>>> to extract the record I want and then use ncl to process it.
>>>>
>>>> I am wondering if there are ways to access the 1st record in ncl.
>>>>
>>>> I am using ncl 6.1.2 (not OPeNDAP-enabled pre-compiled binary)
>>>>
>>>> Thanks.
>>>>
>>>>
>>>> Winston
>>>>
>>>>
>>>> Winston Hao
>>>> New York State Dept of Environmental Conservation
>>>> 625 Broadway, 9th Floor, Albany, NY 12233-3259
>>>> whao@dec.state.ny.us (518)402-8384 (Work) (518)402-9035 (Fax)
>>>>
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>>
>>
>>
>> --
>> Gerry Creager
>> NSSL/CIMMS
>> 405.325.6731
>> ++++++++++++++++++++++
>> „Big whirls have little whirls,
>> That feed on their velocity;
>> And little whirls have lesser whirls,
>> And so on to viscosity.‰
>> Lewis Fry Richardson (1881-1953)
>>
>

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Received on Wed Mar 6 13:27:12 2013

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