From GEMPAK to MetPy: An Updated Tool for Teaching Synoptic Meteorology (and Much More)

For the past thirty years synopticians have had access to GEMPAK as a tool to conduct a wide-range of meteorological analyses, which became invaluable to both teaching and research. This package, developed by NMC (now NCEP) and brought to the University community through Unidata, provides two primary methods for conducting analyses, 1) a (relatively simple) declarative syntax that has a moderate learning curve and 2) a series of GUI interfaces to access and create analysis graphics. In 2008 it was announced that NCEP would no longer actively develop the program; however, Unidata declared it would continue to support the program until suitable replacements were ready.

Over the intervening decade, the Unidata version of GEMPAK has continued to be well utilized across the community, but the inherent limitations that accompany a stand-alone analysis tool with a difficult to maintain data format makes its use outside of the academy very limited. Increasingly the larger scientific community has adopted Python as their preferred computing language and as a result there is a wealth of modules that are focused on scientific computing (e.g., numpy, scipy, scikit-learn, astropy, etc.). Over the past decade, and especially over the past three years, focused efforts at developing the next-generation tool for meteorological analysis has been taking place within the Python ecosystem. Specifically, a meteorologically-focused analysis package (MetPy) has been actively developed at Unidata to meet the needs of the atmospheric science community by developing calculation parity to GEMPAK and a simplified syntax to reduce to the initial learning curve associated with using Python and the many modules associated with scientific computing and visualization.

This paper highlights the progress made on the development of MetPy as an updated tool that will serve the meteorological community for the next generation. Specifically, examples of how MetPy can be used to teach a wide range of synoptic meteorology topics will be shown including quasi-geostrophic analysis, isentropic analysis, potential vorticity analysis, skew-T/log-p diagrams, and satellite imagery.