Weather radars are used all around the world to detect rain, hail and snow, as it happens. However, there are times when the radar network can pick up other things as well. While you generally won't see aeroplanes on our radar images (the radar beam is usually beneath the flight path of most flights, and also our radars are calibrated to primarily pick up smaller objects, whereas radars at airports are calibrated differently to primarily pick up aeroplane-sized objects), there is a myriad of other things that can cause interference on our radar images, which I will explain in this blog.

If you were looking at radar imagery overnight Thursday 21 February 2013 or this morning (Friday 22 February 2013), you could be forgiven for thinking that there was quite a lot of light precipitation over the northern half of the North Island and west of Auckland.