[Met_help] Precip observations in MET

[John Halley Gotway]

Victor,

I took the ASCII point observations you provided and converted them to NetCDF with the tool I'm working on.  I've attached them as an example.

However, the forecast file you provided is in NetCDF format.  MET expects gridded data to be provided in Grib format.  That's why we suggest the use the WRF-PostProcessor to destagger the WRF output 
files, interpolate to pressure levels, and write out Grid data.

Do you have your gridded forecasts available in Grib1 format?

Thanks,
John

Victor Homar wrote:
> Hi John,
> 
> Thanks for your responses.
> 
> Your plan to provide us with a tar ball with the whole thing to test it 
> sounds good.
> 
> Answering your questions:
> 1) The format makes good sense. The Message_Type field is a little 
> artificial for the particular set of stations we are dealing with now. 
> These are not synoptic stations but a particular network of our Met 
> Service (They call them "climatological network"). I guess the ADPSFC 
> code will work for all further steps along the verification process.
> Also, and thinking about general users, the format makes good sense 
> because it has been straight forward to adapt our data to it.
> 
> 2) No suggestions, at first thought it looks like a reasonable and 
> versatile format to import generic observations.
> 
> 3 and 4) I uploaded both an observations file and a WRF forecast file to:
> 
> ftp://eady.uib.es/pub/victor/MET/
> 
> The WRF forecast file is a thinned file using the utility "ncks" to 
> include only the variables Times,RAINC,RAINNC,XLONG and XLAT. Let me 
> know if you need the big (3.5Gb) complete WRFout file.
> 
> Thanks for all your help and have a nice weekend,
> 
> Víctor.
> 
> John Halley Gotway wrote:
>> Victor,
>>
>> To answer your questions...
>> This piece of code, like most of MET, would be written in C++.
>> To test it, I'd like to try it out on some data internally and some of 
>> your data as well.
>>
>> I was working on this tool today, and I have some ideas.  As for the 
>> format of the ASCII observation file, I'm thinking that each line 
>> could consist of the following 9 pieces of info:
>> Message_Type Station_ID Valid_Time(YYYYMMDD_HHMMSS) Lat(Deg North) 
>> Lon(Deg East) Elevation(m) Accum(h)_or_Pressure(hPa) Grib_Code 
>> Observation_Value
>>
>> So for example, here are 4 lines of ASCII observation values (I made 
>> them up):
>> ADPSFC SID1 20050810_120100 40.00 -105.00 -9999 12  61 2.01
>> ADPSFC SID2 20050810_120500 41.00 -105.00 -9999 12  61 0.85
>> ADPSFC SID3 20050810_121000 42.00 -105.00 -9999 12  61 0.90
>> ADPSFC SID3 20050810_121000 42.00 -105.00 -9999 500 11 300
>> They consist of 3 observation of 12-hourly accumulated precip (grib 
>> code = 61), and 1 observation of temperature (grib code = 11) at 500 
>> hPa.  I've attached the netCDF (sample_ascii2nc.nc) file that would be 
>> created from these 4 observations and could be used as input to 
>> Point-Stat.
>>
>> The elevation value is not currently used in Point-Stat, but we may 
>> want to use it in the future.  So I've included it as one of the 
>> things to enter, but you can just put fill data in there right now.
>>
>> However, I've realized that Point-Stat needs to be tweaked slightly to 
>> perform point verification of accumulated precipitation.  It wasn't 
>> matching the observations up correctly.  So when I provide you with 
>> this tool to test on your end, I'll probably just send an updated 
>> tarball containing all of the necessary changes.
>>
>> My questions for you are:
>> Does the ASCII observation format make sense, and would it be easy to 
>> use?
>> Do you have any suggestions for changes or additions to the ASCII 
>> observation format?
>> Would you be able to provide me with some of your rain-gauge 
>> observations formatted in this way?
>> And would you be able to provide me with a sample forecast file to 
>> match up to those observations?
>>
>> One last thing to mention.  I realize that the intermediate NetCDF 
>> file format contains a lot of unnecessary fields in it.  We plan to 
>> clean up that file format in the near future and organize it a little 
>> better.
>>
>> Thanks,
>> John
>>
>> Victor Homar wrote:
>>> John,
>>>
>>> We'll be glad to collaborate in creating such a tool which would make 
>>> our (non BUFR users) life much easier with MET.
>>> So far, we tried to create a NetCDF file for Point-Stat but could not 
>>> figure out what are the minimum set of parameters per observation 
>>> that the NetCDF file should include.
>>>
>>> We are currently concerned with observations of 24h accumulated 
>>> precipitation and looking at page 3-10 of the MET User's Guide, it is 
>>> not intuitive to guess valid values for parameters such as "Vertical 
>>> level", "Pressure level"or "Reason code". Attached is a simple file 
>>> (we could provide more information regarding raingauge station 
>>> characteristics) showing an example of the type of ASCII files we 
>>> deal with. Obviously, variations from this format could easily be done.
>>>
>>> What your plans to test the your code would be? Is the code written 
>>> in Fortran or C, or you use a higher level language?
>>>
>>> Best,
>>> Lorena and Víctor
>>>
>>>
>>>
>>>
>>> John Halley Gotway wrote:
>>>> Lorena and Victor,
>>>>
>>>> This question has come up a lot.  We'd like to figure out an easy 
>>>> way for users to incorporate ASCII observations into MET.  I'm 
>>>> wondering if you'd be willing to work with me on developing a
>>>> conversion tool that takes ASCII observations in a format similar to 
>>>> the one you've described and reformat them into the NetCDF format 
>>>> that Point-Stat expects?
>>>>
>>>> So I'm wondering, if I was to provide you with some code for doing 
>>>> this, would you be willing to test it out on your system and let me 
>>>> know how things go?
>>>>
>>>> Hopefully we could figure out a solution and include it in the next 
>>>> release of MET.
>>>>
>>>> If you'd be willing to work with you on this, could you please send 
>>>> me a couple of your forecast files and corresponding sets of ASCII 
>>>> observations? I'll use them to test out the code I write before
>>>> sending it to you.  Otherwise, if you'd like to do it yourself, I 
>>>> could provide you with some more info on how to do it.
>>>>
>>>> Thanks and please let me know,
>>>> John Halley Gotway
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