I have been working on a separate wind speed and direction instrument based on an Arduino controller and a simple numeric LCD display. The Arduino is hooked up to a rotary knob encoder to allow configuration for the RPM factor and impulse count of the attached anemometer. The vane input is a simple 5V range ADC input and the firmware can learn the range and offset from the vane output.
The display updates at a one-second interval with a 10 minute window for gust peaks. With the 8 pole opto- interrupter in the anemometer the resolution is about 0.3Mph.
I designed this as a handy tool to check out the function of wind trees and because of that I have not made a housing for it, but if there is interest, I could create an Arduino shield and maybe add a Barometer/Temp sensors plus a SD card to the mix to make it something a storm tracker could put together.
Documentation and Arduino Sketch can be found here