As weather forecasters, here at MetService we spend a lot of our time poring through data: data from weather stations, data from satellites and radar, from weather balloons and also webcams. This information is all useful for understanding what the weather is doing right now – but how do we know what might happen in the future? Understanding the current weather helps us understand what might come next, but information from numerical weather models also plays a very important part.

You’ve probably heard the phrase ‘heat wave’ bandied about in the news, and perhaps wondered what exactly it means. Does one hot day constitute a heat wave? And how hot is hot? Does New Zealand really get that many heat waves? If you’ve ever found yourself wondering about these things, then look no further!

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.

An explanation of wind speeds and the Beaufort Scale

Sometimes in MetService forecasts, you will see a forecast for “fresh northerlies”. But what exactly does the word ‘fresh’ mean? For many people, the word ‘fresh’ carries connotations of cool or clean air (eg the phrase ‘fresh air’). However, the word ‘fresh’ also has a more technical definition, that comes from the Beaufort Scale.

Mean Wind Speeds vs. Gust Speeds

March 23rd is World Meteorological Day, a day when National Weather Services around the world commemorate the establishment of the World Meteorological Organisation (WMO), which occurred on this day in 1950. WMO is a global agency which co-ordinates meteorological and hydrological activities. Having international collaboration is very important, as weather will not stop and wait at the border between two countries!