During 2004, the International Satellite Communication System (ISCS) – which services aviation weather needs throughout the Atlantic and Pacific regions as part of the World Area Forecast System (WAFS) -- underwent a fundamental change in communication protocol. The X.25 protocol, which for many years was the backbone of ISCS communication, was removed and replaced by TCP/IP. This change to TCP/IP rendered the existing processing and visualization (Star4) systems obsolete, which opened the door to new workstation technology that would improve meteorological analysis. For example, with the new workstation technology, it became possible to look at model data for an aerodrome in Time-Height cross-section, alert on parameter thresholds, or view Significant Weather (SigWx) or Wind-Temperature data over user-defined areas.

This paper will focus on how commercial software, WAFS-MetLab, interfaced to the ISCS in order to replace Star4 systems. WAFS-Metlab operates at key NOAA facilities that feed, service and monitor the ISCS. This paper will also address the changing needs of the ISCS, including the impending termination of T4 (Difax) charts, which for decades have been the basis for pilot briefings worldwide. When the T4 charts are terminated, Wind-Temperature charts will be made from GRIB data, and Significant Weather Charts will be made from BUFR data.