Under reading of windspeed Tempest

I have had my tempest up and running for 2 days now and have noticed that the wind reading for speed is way off. Outside at the moment it is blowing about 15-25mph this is backed up by my local airport which is about 3 miles away. The wind direction to the unit is clear and no obstructions so nothing to affect the readings. Look at video below

A post was merged into an existing topic: Something Wrong With The Anemometer?