there is a solution for this and doesnt require firmware filtering . i started something many months ago but i seem to get preoccupied and forget to publish my findings . i added some very fine plastic thin mesh , i cut it to a slightly larger diameter and place those over the four transducers holes my initial findings were good no wind drop outs during heavy rainfall unfortunately i never took it any further or did any more probably some other teething issue arised and i put it to one side. the idea was after studying how more expensive wind sonic products try to deal with it. not all do it some use a plastic dome shape cover to allow rain splashes to roll and some use a simple plastic thin grill mesh type . i mean very thin ,… a google search on sonic transducers will return many different approaches thats where i found it and initial tests proved ok … beauty of it if your prepared to experiment you are not taking apart or dismantling the product your simply placing a small mesh over the transducers… whilst its not 100% proof of eliminating water splashes but certainly reduces chances of build up …note small mesh gauge …