Tom McDermott <tmcderm@xxxxxxxxxxxxxxxxxxxxx> wrote:
I gathered from one of the messages last week, I believe it was Dan Vietor's,
that NWS will continue to have DIFAX tiff files available at their web sites
even if FOS transmission is terminated as today's notice threatens. If not,
ftp'ing those files is certainly no long-term solution to the dilemma created
by Alden's demise.
It's our understanding from talking to the NWS that the charts on the FTP and
Web servers will go away on April 30 also. We had pushed for that info to be
included in the announcement, but perhaps it will be in the future
notifications indicated in the announcement. The key thing to read in the
announcement is that DIFAX is no longer required to support NWS operations. To
me that would say that they will stop producing DIFAX maps since the products
are available in modern formats (e.g. Redbook Graphics).
In any case, relying on the DIFAX products is a dead end. The Unidata User's
Committee is exploring options for community generated products. I was just at
UW-Madison and looked at the charts they produce using GEMPAK. They've done a
good job and their scripts are available as one of the options that Unidata has
To me, these are much better than using the old DIFAX maps. You can't get
ensemble forecast charts on DIFAX.
Additionally, from a pedagogical view, using the tools that Unidata provides to create and print custom displays seems a better alternative to using DIFAX anyway for exploring the atmosphere. We all went through the process of shading in areas of NVA and PVA on the NGM charts. Wouldn't it be better to use GEMPAK to generate maps with quantitative contours of NVA and PVA rather than use the subjective hand analyses? With DIFAX, the views are dictated by the products that the NWS creates. Those views haven't changed in 30 years, but our knowledge of how best to look at features has. The tools we have can generate the "old" views, but also new views (isentropic analyses, ensemble forecasts, etc). Perhaps using them will help advance the knowledge and science.