B MAPPER

What happened was the change from the RAP version 1 to RAP version 2 occurred on Feb 25th. Gridded data (GRIB files) that Dr Jack downloads contain many parameters. But, when a major revision occurs, the order of parameters that Dr Jack must use for calculations changes. So, his decoders broke at that point. Noticed that he got things working again by Mar 5th.

Something similar happened when NOAA changed from the RUC to the RAP. I worked with him a bit to find out what changed, looked at the code, and gave up trying to figure out how to modify it. Dr Jack figured it out and got the RAP working fairly quickly. This time, it only took him a day or two to make the necessary changes.

NOAA NWS announced the change in the RAP in a technical note around Jan 25th. They point out that GRIB decoding should not depend on the order of the parameters. It would take a tremendous amount of work for Dr Jack to modify his code... something that's not likely to happen. Fortunately, major changes to these models doesn't occur that often.

Walt Rogers WX