Coordinate System For NREL Wind Resource Database

I’m working with geospatial windspeed data from the NREL Wind Resource Database, but it’s not clear what coordinate reference system is being used. I found on their GitHub that they use a “modified Lambert-conic” system, but none of the various Lambert-conic EPSGs or PROJ strings I’ve found online seem to be correct.

Does anyone know how I can find out what’s the exact CRS they used? Thanks 🙂