Finally, a big storm shows up: 07 October 2013

All I can say about today is just WOW!! After more that two weeks of quiet, sunny weather, Pretoria was finally treated to what I can only describe as a true Highveld thunderstorm. I must admit though, I didn't have much hope of anything happening today. We'd had other days in the past two weeks when thunderstorms were forecast but then nothing happened. I figured today would be another one of those days. Am I glad I was proven wrong.

Shelf cloud approaching

In many ways, it was the calm before the storm. And when the storm finally arrived, boy was it something. The shelf cloud was absolutely spectacular as it rolled over the horizon and approached. The lightning was also a hell of a sight to watch.  

At first I thought the storm was part of a squall tine. But I heard from one of my contacts on Facebook that it was part of something called a QLCS or quasi-linear convective system, http://www.meteor.iastate.edu/~ralliss/qlcsmesovorticies.pdf. Today's weather didn't disappoint. Some areas even got hail, although I wouldn't really look forward that. The satellite and radar images for this weather system were absolutely impressive, showing a line of storms stretching from south eastern Botswana all the way through Swaziland to the nothern KZN coast. This was a huge system indeed.

Satellite and radar map from 07 October 2013, showing the quasi-linear convective system over the north eastern part of South Africa. The capture on this map is 20:00. By now the system  had mostly moved on from Gauteng and was largely affecting Mpumalanga, parts of Limpopo and Swaziland. (Courtesy of Kobus Botha Weather, http://www.weatherphotos.co.za/photos/rain_severe_new.jpg)

It was quite amazing how quickly it moved once it had formed. The time that elapsed from the first photo to the last one was less that 10 minutes. During that time, the shelf cloud kept evolving and taking on different forms and the whole system itself looking really menacing as it inched ever closer. Eventually the lightning eventually begun striking a little too close for comfort and I had to pack up my equipment and head for shelter. Storms can very exciting to watch and document but they're also extremely dangerous and every precaution has to be taken to stay safe when outdoors during a storm. Safety always comes first. I shot these photos from the balcony of the first floor of the local shopping centre just outside the gym and as you can see, it left me dangerously exposed to the storm. Add to that the fact that I had a tripod with a remote trigger connected to the camera and the danger was upped tenfold. As soon as I realised that the lightning was dangerously close, I immediately went into action and took shelter. In fact I should have actually taken shelter the first moment I saw the storm on the horizon, but then that would have meant missing out on all the action, and I couldn't let that happen. However, it is still important to take shelter as soon as you see a storm approaching.   

If you would like to know more about quasi-linear convective systems, you can look up Ron Przybylinski, an American meteorologist who is also a leading expert on QLCS and other associated weather phenomenon. You can find one of his many studies on these often mysterious weather systems at this link: http://www.crh.noaa.gov/lsx/?n=qlcslatest