The wx radar does not have a good echo. I flew this latest COB version of the 717 into an airport with 0SM because of rain. The radar was only giving me very lite and scattered returns. I boosted the gain and it made a very small improvement but if you are flying thru heavy rain at varying airspeeds, the radar return should be solid green with some yellow and red cells where the pockets of moisture (rain) are higher.
Possible solution: As developers, Can you simulate a big rain event in another study level add-on plane and see how their radar gives you a return? After doing so can you figure out how to re-program the wx radar for more accurate returns?