Cumulus Support

https://xkcd.com/2737/

It's actually quite difficult to get really high speed readings just from a finger flick on the cups. I think the fastest I can do on a Davis anemometer is somewhere in the 15-20mph range. It's plenty enough to check that it's working but not remotely into hurricane/tornado speeds. MAybe others have stronger fingers.

Try using a hairdryer, or tyre inflation compressor!