20010413: Fwd: GEMPAK & LDM help

George,

The IDD feed carries the NEXRAD products in the NEXRAD feedtype stream.
These are the SDUS5x wmo header products on NOAAPORT.

Here is the action I use for GEMPAK:
##########################################################################
# NIDS Data from NOAAPORT
##########################################################################
NEXRAD  ^SDUS5. .... ([0-3][0-9])([0-2][0-9])([0-6][0-9]).*/p(...)(...)
        FILE    -close  data/gempak/nexrad/NIDS/\5/\4/\4_(\1:yyyy)(\1:mm)\1_\2\3

For FTG NEXRAD for example, all NEXRAD products are:
SDUS55 KBOU DDHHNN /p(...)FTG

You really need to use the AFOS/AWIPS pil to identify which product is
being matched since every NEXRAD product from a given radar has the same WMO
header. Also, the "TTAAII CCCC" part of the WMO, where CCCC is the forecast
office is not necessarily the same as the NNNxxx of the pil. This is because
some forecast offices have more than one radar. Honolulu has 4. As a result,
the above pattern action uses the /p(...)(...) to match the procuct and
nexrad site respectively.

Also, the NOAAPORT data is in zlib compressed form. I added the ability to
handle products in this format in GEMPAK 5.6.A. The data on the
ftp://weather.noaa.gov ftp server is not compressed. But, that data has
the WMO and PIL distribution headers on it, eg:
SDUS55 KBOU DDHHNN
N0RFTG
(product)

I also added the ability to skip past these headers in GEMPAK 5.6.A. Otherwise,
for older versions of GEMPAK, just use the unix "tail +3" command to write
the data from the ftp server to a separate file starting at the NIDS
portion and not the WMO header. That is, the older versions of GEMPAK
expected just the NIDS product with no preceeding FOS/WMO lines since
the products we received did not have those).

At this point on NOAAPORT, the NEXRAD products available (eg the NNN part of the
PIL identifier) are:
N0R  N0S  N0V  NCR  NTP  NVL

These are tilt 0 reflectivity, storm relative velocity, radial velocity,
composite reflectivity, total precipitation and vertically integrated liquid
water.

NWS is in the process of adding the next 3 tilt products as well as
1 hour and 24 hour precip, and echo tops to NOAAPORT. The NWS web pages
provide NOUS/ADMN messages regarding adding those. The most recent I have is:
http://www.unidata.ucar.edu/glimpse/nws-changes-list/2752

Steve Chiswell
Unidata User Support




On Thu, 12 Apr 2001, George Huffman wrote:

> Steve - I should be more up on this, but I need a jump start here. 
> [Actually, I'm not sure if this should go to the mailing list or if 
> it's a support kind of issue.]  As you can see, I have a user who 
> wants to use the radar data that's starting to show up on NOAAPort. 
> Specifically,
> 1. Could you point me to comments about configuring the LDM to grab 
> the radar data?  If you want the routine stream of products for a 
> single site, I'm supposing you can just set the LDM and then pitch 
> what you don't want.
> 2. Could you point me to samples of how to get the raw radar files into 
> GEMPAK?
> 
> Thanks!
> GJH
> 
> >Date: Thu, 12 Apr 2001 10:44:11 -0400
> >From: Larry Belcher <address@hidden>
> >To: "Dr. George Huffman" <address@hidden>
> >Subject: GEMPAK & LDM help
> >
> >George,
> >Just wondering if you know of anyone I might contact for help on getting
> >the raw 88D data into a format that GEMPAK understands. I have discovered
> >that to archive the 88D data, we must request specific sites and times.
> >I've also found a NWS site from which I can ftp the data from. This will
> >probably be the best option, as the ldm must be switched on and off
> >everytime we would want radar data. However, I now have the data for a
> >selected case yesterday (KFTG snowstorm), but cant get the GEMPAK GUI to
> >display it. On the up side, I have learned how to plot surface METAR's
> >with the software, but just can't seem to figure out this radar thing. Any
> >suggestions would be appreciated.
> >Thanks,
> >Larry.
> >
> >
> >___________________________________________
> >Larry R. Belcher
> >Sci. Sys. & Appl. Inc.
> >NASA/GSFC
> >Greenbelt, MD 20771 USA
> >Fax:    +1 301-614-5492
> >Voice:  +1 301-614-6319
> >E-mail:  address@hidden
> >___________________________________________
> >
> >If we knew what we were doing, it wouldn't be called research!
> 
> George J. Huffman, Ph.D.  (Voice)  +1 301-614-6308
> Sci. Sys. & Appl., Inc.   (FAX)    +1 301-614-5492
> NASA/GSFC Code 912        (Email)  address@hidden
> Greenbelt, MD 20771 USA   (Office) Bld. 33 Room C410
>