"As a kid in the 1970s, I was pretty terrified of thunderstorms - used to do all that hiding behind the sofa stuff! Then in 1980 I had a bit of an epic involving lots of very close lightning strikes while on a climbing holiday in the Austrian Alps. That didn't do much to alleviate the fear.

In the mid-late 1990s I rented a place attached to a hill-farm near Machynlleth with big, big views to the north and east. The summers of the mid-90s featured some spectacular storms and we would often sit outside late at night, watching the lightning play about the hills.

During this time, my terror of storms was replaced by a deep fascination with this atmospheric violence. As my interest in storms grew, I found myself grabbing the camera whenever a storm was passing. A few of these early results were OK, looking back - just pot luck!

By 1999, I'd discovered the weather resources on the Internet and had started browsing through American storm-chasing websites. Seeing the amazing images on some of these sites prompted me into learning a lot more about the weather and to go out deliberately to intercept storms picked up on the rainfall radar or the lightning-detection plots available on the web.

In August 2000, this finally paid off when an intercept to the SE of Machynlleth produced a superb funnel-cloud descending from the base of the parent Cumulonimbus storm-cloud. After that I was hooked!

Today, there is a growing community of storm-chasers here in the UK. We swap data and forecasts via several email message-boards and several of us run our own severe weather dedicated websites. My site is dedicated to Mid-Wales, which is not the easiest area in which to chase.

Successful storm chasing requires safe vantage-points with open views. On Mid Wales' main roads - a lot of which run through hills and wooded valleys - this can be difficult. You can't just stop if there's something good up ahead: it needs to be a safe place. So places to stop safely with a decent view have to be found and remembered for future occasions.

A typical day's chasing (and it is only worthwhile a few days in any one year) begins with an early look on the Internet, downloading all the data and forecasts and poring over the details. After an hour or two I will have made my forecasts for Mid-Wales: usually there is a particular time of day that is likely to produce results.

As this time approaches all the new data - rainfall radar, satellite & lightning - are double-checked and a target area is selected, often at quite short notice. Then it's off in the car with camera to intercept the selected feature.

On arrival in the target area it's often a waiting game as the weather approaches. Sometimes we get it all wrong and the storm fizzles out. But sometimes it's spot on and I'm clicking away like mad! The power of the Internet is amazing. I get emails from all over the world from people who have seen the site and the images.

Quite a few emails come from Welsh people now living overseas, who appreciate the images of home. Others come from seasoned Tornado Alley chasers. Over there a big storm may attract dozens of chasers in vehicles so well equipped that they resemble mobile weather stations! Over here it's likely that a lot of big storms go un-photographed, or there's just me or one of the other UK chasers in position with camera at the ready!

A word about safety. Storm-chasing has to be done responsibly which means driving carefully. It means understanding what is going on so that a controlled storm intercept can be made without racing like a demon in the direction of the nearest black cloud. The precipitation cores of storms, where you get all the heavy rain and hail, are generally avoided, because a) they make driving hazardous and b) the visibility is poor so photography is impossible.

Lightning is another factor. If lightning is striking in the area it is essential to stay under cover in the car. Big, organised storms are potentially very dangerous and should be treated with due respect. But if common sense is used, storm-chasing can be an extremely rewarding branch of landscape photography - and you learn a great deal about meteorology in the process!" By John Mason from Machynlleth .