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Re: description of NAM



Hi Geoff,

I've made the documentation changes you requested to the underlying
files. I will push them out to our server shortly.

The "Best Time Series" aggregation is generated by our FMRC (Forecast
Model Run Collection) aggregation. The FMRC takes a time series of runs
from a given model and creates several virtual aggregated datasets
including a 2 time dimension, 5-D dataset and several datasets with a
single time dimension. This AGU poster describes the different single
time dimension datasets

http://www.unidata.ucar.edu/staff/caron/presentations/FmrcPoster.pdf

For all the NCEP model data we serve
(http://motherlode.ucar.edu:8080/thredds/idd/models.html ), the
underlying data is the GRIB data we get from NOAAPORT and CONDUIT. We
read from those data files (for which we have built indexes) to satisfy
requests for data from the virtual datasets.

Since the spatial domain of the FWIS can change for each run, we won't
be able to do a full FMRC aggregation. Each FMRC aggregation expects all
the data for each run of the model to be on the same grid. So, we can
serve the data from each FWIS run on its own. But we'll have to think
about what else it makes sense to do, e.g., "Best Time Series". I'll
touch base with Rich and ask what he is trying to do with the data, how
he would like to access it.

Geoff, can you explain how the location of each FWIS run is determined?
Is it an automated process? Or does someone/group decide? Also, are
there times when the location stays the same across runs? Is the
information on the domain for each run available somewhere besides the
grid description in the resulting GRIB files?

Thanks,

Ethan

On 12/1/2011 7:51 AM, Linda Miller wrote:
> Hi Geoff,
> 
> Comments inline below.
> 
> On 12/1/2011 7:31 AM, Geoff DiMego wrote:
>> Linda;
>>
>> Hope all is going well for you and yours especially now that the
>> hectic holiday season is upon us ^_^
>>
>> I hate to be a bother, but I have a favor (yes ANOTHER one!) and a
>> question to ask.
> No apologies needed
>>
>> A USGS user had asked me whether we would be making "Best Time Series"
>> aggregations for the new NAM nests (4 km CONUS, 6 km Alaska, 3 km
>> Hawaii & 3 km Puerto Rico-Hispaniola).  I pleaded ignorance.  He
>> pointed me at
>> http://motherlode.ucar.edu:8080/thredds/catalog/fmrc/NCEP/NAM/CONUS_12km/catalog.html?dataset=fmrc/NCEP/NAM/CONUS_12km/NCEP-NAM-CONUS_12km-noaaport_best.ncd
>>
>> which I admit I was unaware of - my bad, but I recognize the unique &
>> useful aspect of this product which you are constructing.
> 
> If  you ever get to Boulder, you should plan to visit Unidata.  We could
> bring you up to speed with what;s going  on here.  You might find some
> of the projects of interest to NCEP.
> 
>>
>> The favor is to update the 3rd Summary bullet under Documentation to:
>> NCEP Nonhydrostatic Multiscale Model on B-grid (NMMB) running in the
>> NOAA Environmental Modeling System (NEMS) infrastructure, and
>> Gridpoint Statistical Interpolation (GSI) analysis.  You could also
>> add a bullet called NCEP Analysis documentaton / tutorial and link it
>> to http://www.dtcenter.org/com-GSI/users/tutorials/11_2.php .
> 
> I'm sure we can do that.  I've cc'd Doug Dirks and Ethan Davis who can
> check it out and make the appropriate edits.
> 
>>
>> My question comes from the one the USGS guy asked: are you planning to
>> aggregate Best Time Series for the new NAM nests?
> 
> I'll bet the "USGS guy" is Rich Signell, who is a liaison to our Users
> Committee.  He definitely keeps us on our toes.  I'll defer your
> question to Ethan.
> 
> Hope  your holidays are joyful!
> 
> Linda
> 

-- 
Ethan Davis                                       UCAR Unidata Program
address@hidden                    http://www.unidata.ucar.edu