Re: DIFAX situation

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Hi Pam-

Thanks for your reply regarding the DIFAX situation. In fact, I was copied on the message containing the alternate sites, and have been using the Unidata site for class to some extent. It does not contain all I need (specifically upper air maps and analyses, with actual data, and not model data), and, more importantly, we have had a hard time getting in. One day we could not get maps from either the Unidata site or the HPC graphics site, which was my fallback.

That's why generating the products locally is the best option.

That leaves the other two locations which cannot be readily viewed. I have asked Mark to explore those sites which involve uncompressing, FTP'ing, etc, and am eagerly awaiting an example to examine from those two sites.

University of Wisconsin-Madison has offered to make the scripts they use to 
generate the PostScript files of their DIFAX-like products available to anyone 
who wants them. Mark should contact Pete Pokerant (poker@xxxxxxxxxxxxxxx) to 
get copies. These will have to be tailored to your own needs, so it's not just 
plug and play. Alternatively, you could talk to Pete P. about having the 
products automatically shipped to you via LDM as they are generated. I'm not 
sure what his reaction to that would be, but this possibility has been 

While McIdas may be able to fill in to some degree once the proper batch files are written (you mentioned some scripts from SSEC?), we cannot print from GARP, which renders it minimally helpful (also, the upper air data plots, but it cannot be contoured in GARP).

I would suggest using GEMPAK, not McIDAS to create the products (that's what UW 
is doing) because GEMPAK has a PostScript driver that provides cleaner images.  
The scripts would run from cron to generate products.  You could also have them 
create GIF's to put on a local Web site if you wanted.

GARP was never intended to be a product generator, just a product viewer, 
that's why printing capabilities are not available.  You could save the plot as 
a GIF and then print the GIF. However, the quality is poorer than GEMPAK 
PostScript output.

Bottom line....I do not currently see any product that can adequately substitute for DIFAX

That seems to be the general consensus among those who still use DIFAX.  
However, there will be a day when there is no DIFAX so other substitutes will 
be necessary.

(not to mentiont that products like the 700mb Vert Displacement Chart are 
essential to me, and I can't imagine will be available from any of the sources 

It should be available from the NWS site.  Their web page:

says "The latest version of each weather chart available for distribution from the 
NWS Telecommunication Gateway on the DIFAX satellite broadcast system to the WSFOs is 
available on this server."  I'm not sure which chart you are actually talking about, 
so I can't give an exact URL.  (Do you mean the 700 mb Vert Vel panel on the models? - if 
so, it is available at:  BTW, a note went 
out from UMass-Lowell to the difax@unidata list yesterday explaining how they are FTPing 
the charts from the NWS site automatically and either printing or viewing the charts on 
screen.  You could contact Frank Colby (Frank_Colby@xxxxxxx) for more information.

Again, once DIFAX goes away, it is our understanding that the charts on their 
web site will also disappear, so using that site is not a long term solution 
and other alternatives will be necessary. All the data necessary to create the 
non-manual charts is available in the datastream.

   OK....enough venting....Thanks again for your reply, and I will continue to 
pursue solutions at this end.

I understand your frustration. This issue has consumed a awful lot of the User 
Committee's (of which Bill is now a member) and the UPC staff's time and 
energy. We can't change the NWS's mind on terminating DIFAX which is no longer 
needed for their operations (in some ways I wish they'd just pull the plug 
already rather than drag this out). All we can do is help sites effectively use 
the plethora of data that they receive via IDD to create similar products 
locally or help them find other sites that are willing to pregenerate products 
if they do not have adequate local expertise with McIDAS and GEMPAK.  That is 
the crux of Unidata - a community of sites working together to solve problems.  
The UPC is a facilitator in this community interaction, but the hard work needs 
to be done by the community members.  Sites like UW have stepped up to help 
solve the demise of DIFAX.  We hope others will do the same and then share 
their work with the rest of the community.


"Pam Grube" <grubep@xxxxxxxxxxxxxxxx> wrote:


Thanks again....I will continue to investigate some of these options, as my teaching depends on a suitable solution.

Pam G.

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