There are many way to do this. The best way? Depends on your exact use case and equipment.
In general, you have to find a way to transport the desired data from the device weewx is running, to the display.
Basically, what you will have to do is to configure a report for the max wind speed and the average, output is simple text. On top of that you will, you will listen to windSpeed/windGust/windDir in the loop and display these values on the display.
Still, there are 1001 way to achieve this.