[Met_help] Using MET with fcst_lead >= 100 h

Thu Jan 7 12:14:55 MST 2010

John,

No those "HH" arguments to PCP-Combine should be fine.  Perhaps listing the HH as 2-digits is misleading, but it'll read the integer number of hours (any number of digits) and handle them correctly.

To make sure, I ran PCP-Combine on some that that included accumulations intervals > 100 hours.  All three commands (sum, add, and subtract) worked fine even when the accumulation interval on the
command line was > 100.

Please let me know if anything else comes up.

John

John Henderson wrote:
> Hello again John,
> 
> Regarding the > 99-h forecast lead time problem from a couple of weeks
> ago... I believe that PCP_COMBINE will also need to be modified since
> there is an argument to the code that is of the format HH (for the 'sum'
> option: out_accum).
> 
> Please let me know if this is actually the case.
> 
> Thanks.
> 
> John Henderson
> 
> On 12/23/09 5:46 PM, John Halley Gotway wrote:
>> John,
>>
>> I checked and found out that this really is a problem for the
>> STAT-Analysis and MODE-Analysis tools.  When I ran STAT-Analysis and
>> specified a lead time of "-fcst_lead 114", it errored out with an error
>> message about not being able to parse that time.
>>
>> So I modified the library code which parses these strings to allow for
>> the
>> lead hours to be either 2 or 3 digits long.
>>
>> I've posted the fix to:
>> http://www.dtcenter.org/met/users/support/known_issues/METv2.0/index.php
>>
>> Thanks for pointing out this problem, and please let me know if you
>> uncover any more issues.
>>
>> Thanks,
>> John
>>
>>   
>>> John,
>>>
>>> Thanks for the clarification of everything.
>>>
>>> I'll let you know if I uncover any other problems with triple-digit lead
>>> times, but, otherwise, I'll await your fix.
>>>
>>> Thanks for the quick responses!
>>>
>>> John
>>>
>>> On 12/23/09 4:37 PM, John Halley Gotway wrote:
>>>     
>>>> John,
>>>>
>>>> Regarding WPP, I really don't think that you'll have a problem.  I'm
>>>> currently working on a project with folks from NOAA where we're
>>>> creating
>>>> forecasts out to 114 hours and are running the most recently released
>>>> version of WPP just fine.  You would only potentially have an issue if
>>>> you
>>>> were running your forecasts out>   255 hours.
>>>>
>>>> Regarding issues with MET, you're probably correct.  I think this would
>>>> come up in your use of the MODE-Analysis and STAT-Analysis tools.
>>>> That's
>>>> the place you'd be specifying the forecast lead time in the config file
>>>> or
>>>>    on the command line.  I believe it would be a pretty easy fix
>>>> involving
>>>> changes to the "timestring_to_sec" routine in the file
>>>> METv2.0/lib/vx_cal/time_strings.cc.
>>>>
>>>> However, before making any changes, I'd like to do some testing to make
>>>> sure it really is a problem.  And once I verify that, I'll work on a
>>>> fix.
>>>> If I isolate the problem and come up with a fix, I'd post it to the MET
>>>> website and update the package of bug fixes.
>>>>
>>>> I'll let you know how it pans out.  Please let me know if, in your use
>>>> of
>>>> MET, you find another place where it's a problem to have forecast
>>>> hours>
>>>> 99.
>>>>
>>>> Thanks,
>>>> John
>>>>
>>>>
>>>>       
>>>>> Hello John,
>>>>>
>>>>> Thanks for the prompt response. Perhaps I had briefly come across the
>>>>> WPP email and thought it was actually related to MET...
>>>>>
>>>>> I believe - according to the user manual - that MET allows the user to
>>>>> specify forecast lead time as HH[MMSS], which seems to me to prevent
>>>>> leads times>   99h. Am I mistaken?
>>>>>
>>>>> Regarding WPP...I intend to verify precip accumulation in MET for a
>>>>> year-long series of 5.5-day forecasts that overlap at the beginning of
>>>>> each forecast run to avoid spin-up problems. It's a pretty standard
>>>>> way
>>>>> of generating year-long WRF simulations. However, that means that I
>>>>> will
>>>>> be applying WPP to WRF forecasts with forecast lead times of 12 h to
>>>>> 132
>>>>> h. I hadn't anticipated any problems with WPP, unfortunately. I have a
>>>>> vague memory that someone had come up with a fix for the long-lead
>>>>> time
>>>>> problem, but I'm not sure. Would you be able to investigate the status
>>>>> for me?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> John
>>>>>
>>>>> On 12/23/09 2:51 PM, John Halley Gotway wrote:
>>>>>
>>>>>         
>>>>>> John,
>>>>>>
>>>>>> I looked back through the old MET-Help emails and couldn't find
>>>>>> anything
>>>>>> that would explain a problem of using fcst_lead>= 100 hours.  So I'm
>>>>>> not
>>>>>> aware of a problem with that.  I did find one email
>>>>>> related to this but I believe that was due to an incorrectly packed
>>>>>> GRIB
>>>>>> file, not a problem in MET itself.
>>>>>>
>>>>>> However, there are some issues in WPP (WRF-PostProcessor) for
>>>>>> accumulated precip when the forecast lead time extends beyond 255
>>>>>> hours.
>>>>>>    The time value of 255+ overflows the single byte that's
>>>>>> allocated in the GRIB record to store that time info.  This is mostly
>>>>>> an
>>>>>> issue for accumulated precip since you have to store 2 times in the
>>>>>> GRIB
>>>>>> record - accumulation starting and ending times.  I'm
>>>>>> not sure of the status of this issue, but if you run across it, I can
>>>>>> look into it more.
>>>>>>
>>>>>> I'd say, proceed with trying to use MET to verify forecasts>= 100
>>>>>> hours.
>>>>>>    And if you run into any problems, just let us know through
>>>>>> met_help at ucar.edu.
>>>>>>
>>>>>> If you haven't already done so, I would suggest retrieving the latest
>>>>>> set of bug fixes for METv2.0 from:
>>>>>> http://www.dtcenter.org/met/users/support/known_issues/METv2.0/index.php
>>>>>>
>>>>>>
>>>>>> Hope that helps,
>>>>>> John Halley Gotway
>>>>>> johnhg at ucar.edu
>>>>>>
>>>>>> John Henderson wrote:
>>>>>>
>>>>>>
>>>>>>           
>>>>>>> Hello,
>>>>>>>
>>>>>>> When first I installed WRF-MET I believe I saw a discussion
>>>>>>> somewhere
>>>>>>> about how to apply WRF-MET to forecasts that require a fcst_lead of
>>>>>>> at
>>>>>>> least 100 h, however, I can't seem to find it now. Can you point me
>>>>>>> in
>>>>>>> the right direction?
>>>>>>>
>>>>>>> Thanks.
>>>>>>>
>>>>>>> John Henderson
>>>>>>> AER, Inc.
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Met_help mailing list
>>>>>>> Met_help at mailman.ucar.edu
>>>>>>> http://mailman.ucar.edu/mailman/listinfo/met_help
>>>>>>>
>>>>>>>
>>>>>>>              
>>>>>          
>>>>
>>>>        
>>>      
>>
>>    