From Chuck:
Natlie et al. FYI, that the document “displaying_wind_vectors_in_ArcMap.pdf” in the \WindNinja\WindNinja-3.11.1\share\windninja\doc\ location is no longer valid.
ArcMap has been deprecated by ESRI and the current version of ArcGISPro being supported by the USFS and others is version 3.3.
ESRI has changed so much of the look and operation of the symbology in ArcGISPro to rotate and scale the wind arrows that the ArcMap version of the document is no longer helpful.