How to plot GOES-17 Full Disk Imagery in GEMPAK 7

How to fix the map in full disk GOES-17 GEMPAK plots

By default, the new GOES-17 full disk level 2 satellite data is improperly mapped by GEMPAK 7.5.1. From a level 2 netcdf4 file with this name: OR_ABI-L2-CMIPF-M6C14_G17_s20192821810340_e20192821810340_c20192821810340.nc you get the image below on the left. Note that Africa and Asia are plotted on the globe as if seen from the opposite side of the earth. By editing a shapefile, hipowo.gsf, and removing all areas outside the longitude range of the satellite view, I have been able to create the image below on the right.
My edited shapefile, hipowo.g17 is available here. An edited shapefile for GOES-16 (which may also be useful) is found here.

The procedure for creating the shapefiles is this:

  1. used GEMPAK gsfssf program to convert hipowo.gsf to an ascii file.
  2. wrote a simple FORTRAN code, mapasciitoascii.f that skipped any areas that were beyond 90 degrees of longitude off of GOES-17's center longitude of -137.
  3. took that hipowo.a17 ascii file and converted it back to binary format using: $GEMEXE/ssfgsf -o hipowo.g17 hipowo.a17

Note, the underlying problem with GEMPA 7.5.1 seems to be that it is not properly handling the x coordinate (longitude) of these satellite projections. You can see this by choosing smaller GAREA values. For example:
garea = 10;130;40;70
behaves as if you had specified negative longitudes, i.e., it gives you what you'd expect to get if you had entered
garea = 10;-130;40;-70
I do not know exactly how to fix this in GEMPAK, so that is why I came up with this workaround.

David Ovens
Department of Atmospheric Sciences
University of Washington
October 28, 2019