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[Datastream #DEJ-475879]: plea for Nexrad III help

> Hello:

Hi Lori, 

> 
> We are working with the SLC WFO on a fast running HMS model for flood
> warnings occurring on a 1 hour peak time.  They want a model in between
> a FFG response protocol and RFC response.
> 
Great!

> My hold up is their need to use Nexrad gribs. 

Do you really mean GRIB..i.e "gridded binary"?

WSR-88D provides binary radial scans, which is not "gridded".

Are you referring to some level III products (there are some gridded post 
processed products).

Are you hoping to use the level II data or the Level III products?

What files/products are you currently working with? Knowing this will help us 
better answer your question

 We can convert them in
> multiple steps to the format we run our Corps models but apparently
> the time intervals between the 5 minute radar sweeps are not exactly
> 5 minutes.

Nope, it varies due to the mechanical nature of the RADAR itself..also, clear 
air mode scans are nominally every 6 minutes.

> 
> I tried to fake out the start/end times on the 5 minute files but I
> guess there is a hidden binary stamp in the file that knows it is not
> exactly 5 minutes.

Correct

> 
> It is confusing how the RFC, WFO, and NCEI all have different formats.

They all use WSR-88D format, some use compression some do not.

Please see:

https://www.ncdc.noaa.gov/data-access/radar-data/radar-decoding

> Our experts wondered if the WFO could somehow convert these scans to
> XMRG on the fly.  We could then run a batch/cron to process these XMRG
> files every hour for them or as needed.

Sure seems reasonable, but that is obviously out of our control

> 
> No one seems to understand the details or format subtleties.  Can you
> refer me?

I would encourage you to view the ICD (Interface Control Document) located at:

 https://www.roc.noaa.gov/WSR88D/BuildInfo/Files.aspx

..or if you have more specific questions, hopefully we can answer them here  :)


> 
> Lori L. Schultz
> SPK-Hydraulic Analysis Section
> 916-557-7226
> 

Hope this helps you along, please let us know if we can help further

Jeff

Jeff Weber
Unidata User Support
http://www.unidata.ucar.edu

Ticket Details
===================
Ticket ID: DEJ-475879
Department: Support Datastream
Priority: Normal
Status: Open
===================
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