[gradsusr] Getting SREF Probability Variables To Plot In GrADS

Jennifer Adams jma at cola.iges.org
Fri Jun 6 14:31:56 EDT 2014


So, at last, all the records in your file have matched. Can you display them?

I took a look at the file you pointed to 
>> at:http://ftp.ncep.noaa.gov/data/nccf/com/sref/prod/sref.20140604/15/ensprod/sref.t15z.pgrb132.prob_3hrly.grib2

This file is not the same as the one you are looking at. That file has 4980 records, and you appear to have only 7. So, how exactly did you create your subset file? 

I ask this because the file being served by NCEP is peculiar in that is has at most 4 records that would match a given ctl entry. For clarity, I will focus on only one varible, with a descriptor file entry like this:
  p3   0,1,0    a1,0.25    0,1,8,1    Probability of accumulated precip above 0.25

It is easy to find the records for this variable by grepping for "0.25" in the wgrib2 output. 

# wgrib2 sref.t15z.pgrb132.prob_3hrly.grib2 | grep ">0.25" 
182:10551812:d=2014060415:APCP:surface:0-3 hour acc fcst:prob >0.25
298:19945733:d=2014060415:APCP:surface:3-6 hour acc fcst:prob >0.25
308:20541156:d=2014060415:APCP:surface:0-6 hour acc fcst:prob >0.25
434:30428673:d=2014060415:APCP:surface:6-9 hour acc fcst:prob >0.25
444:31008021:d=2014060415:APCP:surface:3-9 hour acc fcst:prob >0.25
570:41155064:d=2014060415:APCP:surface:9-12 hour acc fcst:prob >0.25
580:41728223:d=2014060415:APCP:surface:6-12 hour acc fcst:prob >0.25
590:42476633:d=2014060415:APCP:surface:0-12 hour acc fcst:prob >0.25
726:53157513:d=2014060415:APCP:surface:12-15 hour acc fcst:prob >0.25
736:53746450:d=2014060415:APCP:surface:9-15 hour acc fcst:prob >0.25
746:54503902:d=2014060415:APCP:surface:3-15 hour acc fcst:prob >0.25
882:65476225:d=2014060415:APCP:surface:15-18 hour acc fcst:prob >0.25
892:66095269:d=2014060415:APCP:surface:12-18 hour acc fcst:prob >0.25
902:66876471:d=2014060415:APCP:surface:6-18 hour acc fcst:prob >0.25
1038:78030238:d=2014060415:APCP:surface:18-21 hour acc fcst:prob >0.25
1048:78673344:d=2014060415:APCP:surface:15-21 hour acc fcst:prob >0.25
1058:79484823:d=2014060415:APCP:surface:9-21 hour acc fcst:prob >0.25
1194:90543385:d=2014060415:APCP:surface:21-24 hour acc fcst:prob >0.25
1204:91189108:d=2014060415:APCP:surface:18-24 hour acc fcst:prob >0.25
1214:92014359:d=2014060415:APCP:surface:12-24 hour acc fcst:prob >0.25
1224:93013217:d=2014060415:APCP:surface:0-1 day acc fcst:prob >0.25
etc.

The last four records in this list all have the same valid time, 24hrs from initialization, and they will all MATCH the set of grib codes in the descriptor entry above, yet they are not the same thing. Record 1194 is a 3hr accumulation, record 1204 is a 6hr accumulation, record 1214 is a 12hr accumulation, and record 1224 is a 24hr accumulation. If more than one record MATCHES a descriptor file entry, only the final one will be entered in the index file -- in this case, you would be displaying the data in record 1224, the 24hr accumulation. If you ran gribmap with the -0 option (to match with the inital time in an averaging/accumulation period) you would still have four records that match the 00hr time step: records 182, 308, 590, and 1224. 

So, some careful examination of the metadata and then subsetting of the NCEP files is required before you can be 100% certain of what you are looking at when it comes to these SREF probability forecasts. I am not surprised that g2ctl is confused. 

 --Jennifer

p.s. This time axis covers all the timesteps in the forecast: TDEF 30 linear 15Z04jun2014 3hr


On Jun 6, 2014, at 12:34 PM, Perry, Aaron @ LSC wrote:

> Hi Jennifer,
> 
> Here is the output from gribmap -v:
> 
> [aaron at arrakis 09Z]gribmap -v sref_prob.20140606.09z.ctl
> Invalid command line argument: sref_prob.20140606.09z.ctl Ignored.
> 
> Enter name of Data Descriptor file: sref_prob.20140606.09z.ctl
> gribmap: scanning GRIB2 file: /home/aaron/grads/data/sref_prob/20140606/09Z/sref_prob.20140606.09z.grib2
> 1.1: lev1=1,0 a1,1.27 var=0,1,8,1 MATCH
> 2.1: lev1=1,0 a1,12.7 var=0,1,8,1 MATCH
> 3.1: lev1=1,0 a1,0.25 var=0,1,8,1 MATCH
> 4.1: lev1=1,0 a1,38.1 var=0,1,8,1 MATCH
> 5.1: lev1=1,0 a1,2.54 var=0,1,8,1 MATCH
> 6.1: lev1=1,0 a1,101.6 var=0,1,8,1 MATCH
> 7.1: lev1=1,0 a1,12.7 var=0,1,8,1 MATCH
> gribmap: Writing out the index file
> 
> For the record, when I automatically run the grib2 through g2ctl/gribmap, it automatically sets the date to 1 day ahead (09Z07jun2014 instead of 09Z05jun2014), sets TDEF to 10, not 27 and only has one variable, APCP, so I have to copy/paste the 7 defined variables of QPF probability.
> 
> 
> 
> 
> Onward and Upward,
> 
> Aaron D. Perry
> Atmospheric Sciences
> Lyndon State College
> Class of 2016
> Boston, MA 
> Twitter: @AaronPerryLSC
> Mobile: 617-780-4312
> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
> Sent: Friday, June 06, 2014 12:15 PM
> To: GrADS Users Forum
> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
> 
> OK, so what about the output from gribmap with the new TDEF?  --Jennifer
> 
> 
> On Jun 6, 2014, at 12:12 PM, Perry, Aaron @ LSC wrote:
> 
>> Sorry about that.
>> 
>> Specifically, I am trying to get the QPF probabilities GRIB2, which to my understanding is located at:http://ftp.ncep.noaa.gov/data/nccf/com/sref/prod/sref.20140604/15/ensprod/sref.t15z.pgrb132.prob_3hrly.grib2
>> 
>> I've then been using g2ctl/gribmap to create the necessary .ctl/.idx files, though more recently with all this troubleshooting, I've just been editing one control file. 
>> 
>> Originally, I tried using the method that was posted here (http://gradsusr.org/pipermail/gradsusr/2011-November/031529.html)
>> 
>> 
>> Onward and Upward,
>> 
>> Aaron D. Perry
>> Atmospheric Sciences
>> Lyndon State College
>> Class of 2016
>> Boston, MA 
>> Twitter: @AaronPerryLSC
>> Mobile: 617-780-4312
>> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
>> Sent: Friday, June 06, 2014 11:03 AM
>> To: GrADS Users Forum
>> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
>> 
>> Aaron, there are quite a file subdirectories under http://ftp.ncep.noaa.gov/data/nccf/com/sref/prod/sref.20140604/15. Could you please be completely specific about the URL that points to the file you are trying to read?  Also, your TDEF starts 00z01jun with only 10 3-hour time steps -- this will not cover the apparent time range of your data, it won't even come close to the initial time of your forecast: 15z4jun2014. 
>> 
>> What is the output from gribmap -v on you descriptor with a tdef that looks like like this: 
>> 
>> TDEF 27 linear 15z4jun2014 3hr 
>> 
>> This time axis starts at the initial date of your data file and extend to 21z07jun2014, which is the apparent valid time of the final record in your file. 
>> 
>> --Jennifer
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> On Jun 6, 2014, at 6:40 AM, Perry, Aaron @ LSC wrote:
>> 
>>> Hi Jennifer,
>>> 
>>> Here's my data source:
>>> 
>>> http://ftp.ncep.noaa.gov/data/nccf/com/sref/prod/
>>> 
>>> 
>>> 
>>> Onward and Upward,
>>> 
>>> Aaron D. Perry
>>> Atmospheric Sciences
>>> Lyndon State College
>>> Class of 2016
>>> Boston, MA 
>>> Twitter: @AaronPerryLSC
>>> Mobile: 617-780-4312
>>> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
>>> Sent: Friday, June 06, 2014 6:31 AM
>>> To: GrADS Users Forum
>>> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
>>> 
>>> Can you point me to the source of your data file? --Jennifer
>>> 
>>> On Jun 5, 2014, at 1:29 PM, Perry, Aaron @ LSC wrote:
>>> 
>>>> Jennifer,
>>>> 
>>>> After carrying out your suggestions, I am still getting the "Data Request Warning/Cannot Contour" errors.
>>>> 
>>>> I've attached the control file and the GrADS script that I'm using to try and plot, at this point, anything.
>>>> 
>>>> 
>>>> 
>>>> Onward and Upward,
>>>> 
>>>> Aaron D. Perry
>>>> Atmospheric Sciences
>>>> Lyndon State College
>>>> Class of 2016
>>>> Boston, MA 
>>>> Twitter: @AaronPerryLSC
>>>> Mobile: 617-780-4312
>>>> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
>>>> Sent: Thursday, June 05, 2014 6:49 AM
>>>> To: GrADS Users Forum
>>>> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
>>>> 
>>>> Looks like you need to change your time axis to be 3 hourly and extend it to 00z21jun. --Jennifer
>>>> On Jun 4, 2014, at 8:46 PM, Perry, Aaron @ LSC wrote:
>>>> 
>>>>> Hi Jennifer,
>>>>> 
>>>>> I just went back and fixed those variables in the control file.
>>>>> 
>>>>> Here's the output from gribmap -v:
>>>>> 
>>>>> 1.1: lev1=1,0 a1,1.27 var=0,1,8,1 MATCH
>>>>> 2.1: lev1=1,0 a1,12.7 var=0,1,8,1 MATCH
>>>>> 3.1: lev1=1,0 a1,0.25 var=0,1,8,1 valid time 2014060606:00 (t=7.5) has non-integer grid index
>>>>> 4.1: lev1=1,0 a1,38.1 var=0,1,8,1 valid time 2014060612:00 (t=8.5) has non-integer grid index
>>>>> 5.1: lev1=1,0 a1,2.54 var=0,1,8,1 valid time 2014060700:00 (t=10.5) is outside grid limits
>>>>> 6.1: lev1=1,0 a1,101.6 var=0,1,8,1 valid time 2014060709:00 (t=12) is outside grid limits
>>>>> 7.1: lev1=1,0 a1,12.7 var=0,1,8,1 valid time 2014060721:00 (t=14) is outside grid limits
>>>>> 
>>>>> Looks like variables 5-7 are giving me issues, possibly THE issue?
>>>>> 
>>>>> 
>>>>> Onward and Upward,
>>>>> 
>>>>> Aaron D. Perry
>>>>> Atmospheric Sciences
>>>>> Lyndon State College
>>>>> Class of 2016
>>>>> Boston, MA 
>>>>> Twitter: @AaronPerryLSC
>>>>> Mobile: 617-780-4312
>>>>> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
>>>>> Sent: Wednesday, June 04, 2014 6:36 PM
>>>>> To: GrADS Users Forum
>>>>> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
>>>>> 
>>>>> Hi, Aaron -- 
>>>>> You don't need the alias syntax with grib data. The var1.1 syntax is just a dummy variable name that is designed to be unique to the record. You can use use "p1" instead of "var1.1=>p1". 
>>>>> 
>>>>> What is the output from gribmap -v? 
>>>>> --Jennifer
>>>>> 
>>>>> 
>>>>> On Jun 4, 2014, at 6:25 PM, Perry, Aaron @ LSC wrote:
>>>>> 
>>>>>> I took a look at the suggestion documentation and ran grib2scan. Below is a copy/paste link of the output. After reviewing the output, I was able to come up with this modified control file:
>>>>>> 
>>>>>> grib2scan Output: http://paste2.org/zE92be26
>>>>>> 
>>>>>> Modified Control File (Not working):
>>>>>> 
>>>>>> dset /home/aaron/grads/data/sref_prob/20140604/15Z/sref_prob.20140604.15z.grib2
>>>>>> index /home/aaron/grads/data/sref_prob/20140604/15Z/sref_prob.20140604.15z.grib2.idx
>>>>>> undef 9.999E+20
>>>>>> title /home/aaron/grads/data/sref_prob/20140604/15Z/sref_prob.20140604.15z.grib2
>>>>>> * produced by g2ctl v0.0.9
>>>>>> * command line options: /home/aaron/grads/data/sref_prob/20140604/15Z/sref_prob.20140604.15z.grib2
>>>>>> * griddef=1:0:(697 x 553):grid_template=30:winds(grid): Lambert Conformal: (697 x 553) input WE:SN output WE:SN res 8 Lat1 1.000000 Lon1 214.500000 LoV 253.000000 LatD 50.000000 Latin1 50.000000 Latin2 50.000000 LatSP 0.000000 LonSP 0.000000 North Po
>>>>>> dtype grib2
>>>>>> pdef 697 553 lccr 1.000000 214.500000 1 1 50.000000 50.000000 253.000000 16232.000000 16232.000000
>>>>>> xdef 1415 linear 148.637041 0.147586114443721
>>>>>> ydef 573 linear 0.896436 0.147563636363636
>>>>>> tdef 10 linear 15Z04jun2014 6hr
>>>>>> zdef 1 linear 1 1
>>>>>> vars 7
>>>>>> var1.1=>p1 0,1,0 a1,1.27 0,1,8,1 Probability of event above 1.27
>>>>>> var2.1=>p2 0,1,0 a1,12.7 0,1,8,1 Probability of event above 12.7
>>>>>> var3.1=>p3 0,1,0 a1,0.25 0,1,8,1 Probability of event above 0.25
>>>>>> var4.1=>p4 0,1,0 a1,38.1 0,1,8,1 Probability of event above 38.1
>>>>>> var5.1=>p5 0,1,0 a1,2.54 0,1,8,1 Probability of event above 2.54
>>>>>> var6.1=>p6 0,1,0 a1,101.6 0,1,8,1 Probability of event above 101.6
>>>>>> var7.1=>p7 0,1,0 a1,12.7 0,1,8,1 Probability of event above 12.7
>>>>>> ENDVARS
>>>>>> 
>>>>>> Unfortunately, I am still receiving the "Cannot Contour Grid/Data Request Warning" errors. None of the variables will plot. 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Onward and Upward,
>>>>>> 
>>>>>> Aaron D. Perry
>>>>>> Atmospheric Sciences
>>>>>> Lyndon State College
>>>>>> Class of 2016
>>>>>> Boston, MA 
>>>>>> Twitter: @AaronPerryLSC
>>>>>> Mobile: 617-780-4312
>>>>>> From: gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] on behalf of Jennifer Adams [jma at cola.iges.org]
>>>>>> Sent: Wednesday, June 04, 2014 11:31 AM
>>>>>> To: GrADS Users Forum
>>>>>> Subject: Re: [gradsusr] Getting SREF Probability Variables To Plot In GrADS
>>>>>> 
>>>>>> Aaron, 
>>>>>> Have a look at the doc page on descriptor file elements, under 'vars' and then 'additional codes'.  grib2scan in verbose mode should give you a suitable entry for the descriptor file. 
>>>>>> --Jennifer
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> On Jun 4, 2014, at 8:50 AM, Perry, Aaron @ LSC wrote:
>>>>>> 
>>>>>>> Good Morning All,
>>>>>>> 
>>>>>>> I've followed the steps that were outlined in this post (http://gradsusr.org/pipermail/gradsusr/2011-November/031529.html) a while back regarding getting SREF probabilities to plot in GrADS. I keep getting the "Cannot contour grid/data request" error and I was wondering if someone might know of solution.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> Onward and Upward,
>>>>>>> 
>>>>>>> Aaron D. Perry
>>>>>>> Atmospheric Sciences
>>>>>>> Lyndon State College
>>>>>>> Class of 2016
>>>>>>> Boston, MA 
>>>>>>> Twitter: @AaronPerryLSC
>>>>>>> Mobile: 617-780-4312
>>>>>>> _______________________________________________
>>>>>>> gradsusr mailing list
>>>>>>> gradsusr at gradsusr.org
>>>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>> 
>>>>>> --
>>>>>> Jennifer M. Adams
>>>>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>>>>> 111 Research Hall, Mail Stop 2B3
>>>>>> George Mason University
>>>>>> 4400 University Drive
>>>>>> Fairfax, VA 22030 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> _______________________________________________
>>>>>> gradsusr mailing list
>>>>>> gradsusr at gradsusr.org
>>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>> 
>>>>> --
>>>>> Jennifer M. Adams
>>>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>>>> 111 Research Hall, Mail Stop 2B3
>>>>> George Mason University
>>>>> 4400 University Drive
>>>>> Fairfax, VA 22030 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> gradsusr mailing list
>>>>> gradsusr at gradsusr.org
>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>> 
>>>> --
>>>> Jennifer M. Adams
>>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>>> 111 Research Hall, Mail Stop 2B3
>>>> George Mason University
>>>> 4400 University Drive
>>>> Fairfax, VA 22030 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> <sref_prob.20140604.15z.ctl><sref_qpf_prob.gs>_______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>> 
>>> --
>>> Jennifer M. Adams
>>> Center for Ocean-Land-Atmosphere Studies (COLA)
>>> 111 Research Hall, Mail Stop 2B3
>>> George Mason University
>>> 4400 University Drive
>>> Fairfax, VA 22030 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>> 
>> --
>> Jennifer M. Adams
>> Center for Ocean-Land-Atmosphere Studies (COLA)
>> 111 Research Hall, Mail Stop 2B3
>> George Mason University
>> 4400 University Drive
>> Fairfax, VA 22030 
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
> 
> --
> Jennifer M. Adams
> Center for Ocean-Land-Atmosphere Studies (COLA)
> 111 Research Hall, Mail Stop 2B3
> George Mason University
> 4400 University Drive
> Fairfax, VA 22030 
> 
> 
> 
> 
> 
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr

--
Jennifer M. Adams
Center for Ocean-Land-Atmosphere Studies (COLA)
111 Research Hall, Mail Stop 2B3
George Mason University
4400 University Drive
Fairfax, VA 22030 





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