DIFAX

Greetings:

By now it is common knowledge that Alden is no longer a supplier of Difax 
products. This has brought to the forefront the larger question of the future 
of Difax, along with a flurry of healthy email about the role of Difax and the 
creation of difax-like products by the community.  Let us first recognize that 
the days of Difax are limited (Alden or not).  I believe that the fading of 
Difax affords us the opportunity to build a better mouse trap. Here are some 
things that have been going on to treat the symptoms of Difax withdrawal.

Unidata staff, notably Jeff Weber, have been busy compiling community-generated 
alternatives that can be employed to create Difax-like products.  Jeff has added a 
link to these alternatives that can be accessed via www.unidata.ucar.edu go to 
community, then Difax alternatives 
<http://unidata.ucar.edu/community.difax.html>. These scripts, some 
Unidata-produced and others home brew, can be used to create Difax-like products on 
your home server using the IDD datastream, thus eliminating the need for Difax. But 
this is only part of the effort.

Many users may be interested in learning of the initiative by the University of 
Wisconsin (UW), notably Pete Pokrandt, in cooperation with Unidata, to create a 
full suite of difax-like products (about 100) on a UW server, and make those 
products available to the user community.  Testing has been going on for about 
a week at Millersville, Lyndon State, and UC San Diego to obtain Difax-like 
products created at UW, and so far the results have been very positive. 
Currently, the number of products is limited to ETA and MRF runs, surface maps, 
and ETA initializations on constant pressure surfaces, but this number is being 
expanded almost daily.  The maps created by UW are of very high quality, and 
printable on 8.5x11 or 11x17 postscript printers. The topology for product 
distribution has not been ironed out yet, but Unidata and UW are working on it. 
It is likely that the products will be piped into the IDD system. A general 
announcement to the Difax community regarding the availability of these 
products will be forthcoming when a topology has been worked out.

In addition to the UW/Unidata initiative, the user community can, and should, 
participate in generating specialized products that could be distributed to 
other institutions using the IDD topology. Wisconsin should not be seen as 
providing one-stop-shopping for the variety of specialized products that the 
user community may want. Most sites receive the data needed to create the 
charts and could run the scripts that generate them at their own installation. 
That would give the community more control over what is produced, enable us to 
generate products specific to our region, and eliminate a single point of 
failure in the system by providing alternate IDD sources for the maps. Unidata 
can assist institutions interested in developing such products with getting 
those products to the IDD for community-wide distribution.  (Remember that 
Unidata's business is the management of data and software, not the generation 
of products, per se.) Again, if you want to replicate what Wisconsin is doing, 
or create specialized products, you can start the process by obtaining scripts 
using the web link given above.

We have an opportunity to create a suite of valuable products through the spirit of 
cooperation that has become the cornerstone of the Unidata/User Community 
relationship.  Wisconsin is poised to deliver a suite of general products in the near 
future that, if the test products are any indication, should satisfy the most 
discerning user. In addition, specific products and replicates of the Wisconsin suite 
of products can be generated at the local institutions and distributed to others.  
Many believe this is the appropriate path to follow, but Unidata and the UserComm 
continue to solicit your comments through the Difax email list, 
<difax@xxxxxxxxxxxxxxxx>

On behalf of the Unidata UserComm, I would like to extend a sincere thanks to 
Jeff Weber, Pete Pokrandt, Linda Miller and other members of the Unidata staff, 
the test site point persons, and the contributors to the Difax, ldm-users, and 
usercomm email dialogue for their combined efforts. There is still much that 
can be done, but it appears that we are making progress. Unidata staff will 
continue to provide updates as necessary. If you want to participate in the 
ongoing dialogue regarding difax, please subscribe to the difax email list 
(www.unidata.ucar.edu, go to support, then click email lists).

Thanks,
Rich Clark
Unidata UserComm Chair.