GEMPAK, the GEneral Meteorology PAcKage, is an analysis, display, and product generation package for meteorological data. It is developed by NCEP (the National Centers for Environmental Prediction) for use by the National Centers (Storm Prediction Center (SPC), Tropical Prediction Center (TPC), Aviation Weather Center (AWC), Hydrologic Prediction Center (HPC), Marine Prediction Center (MPC), Environmental Modeling Center (EMC), etc.) in producing operational forecast and analysis products such as those distributed as Redbook Graphics and others displayed on the NWS web pages and utilized internally within the centers. Graphical User Interfaces provide convenient access to interactive data manipulation. A comprehensive set of decoders enables integration of real-time and archive data, products, and bulletins. The GEMPAK distribution consists of a suite of application programs, Graphical User Interfaces (GUIs), meteorologic computation libraries, graphic display interfaces, and device drivers for the decoding, analysis, display and diagnosis of geo-referenced and meteorological data.
The Unidata Program Center distributes and provides support for GEMPAK to our member sites. Membership in Unidata is open to U.S. colleges and universities, and is free of charge. GEMPAK is also available as unsupported software without charge to organizations which do not participate in Unidata through the limitations specified in the Unidata participation policy. The Unidata program center release of GEMPAK/NAWIPS incorporates several additions developed both locally and at other locations to enhance the use of real-time data aquired through the Unidata IDD, and through instructional case studies such as those developed at COMET.
GEMPAK provides a powerful interactive user environment for research and education in addition to operational forecasting. Many sites also utilize GEMPAK's text interface programs for classroom and web product generation as well as research and operational/real-time displays through scripts and product generation files. An example of GEMPAK utility within the Unidata community is the IDD data stream delivering facsimile replacement products (eg, the DIFAX feed) generated at the University of Wisconsin. GEMPAK is also being used to generate radar mosaics for the Unidata IDD FNEXRAD data stream by compositing individual NIDS products into a common projection and data set. These products are available to Unidata sites both in the form of images, as well as numerical grids which can be used in diagnostic calculations with other gridded data sets to produce additional value added data.