For those that read our latest article about Little Raith Wind Farm, you may have noticed a picture we captured, that we reckoned was the formation of a funnel of a tornado. At the time the sky darkened, and a funnel began to form, and from nowhere winds began to pick up speed and strength, but then dissipated as a torrent of rain was unleashed.
The image was captured on the 25th August 2012 at around 4:00-4:30pm.
We decided to send the images to a Lochgelly based meteorological expert, Graham Smith, who has built their own local weather station (http://www.fifeweather.co.uk/) and their own mobile weather tracking vehicle (http://www.weatherevents.net/), to get a better understanding of the storm weather system we witnessed, and if it was the formation of a tornado.
The short answer is no, however, if the weather conditions were correct, it could have formed into a tornado, but what we witnessed is termed as a ‘funnel cloud’. Graham has provided us with such an excellent explanation, we have decided to leave it completely to the expert to explain what was happening:
Funnel clouds are not terribly uncommon in the UK, and this summer has been particularly active across the UK for thunderstorms and tornadic events. That said, a majority of them occur in the South East of England. The more North and West you move through the country, the rarer these events become.
Several funnel clouds have been photographed across Scotland already this season, and unless your photos are also from the 14th of July, this would make the second funnel cloud on Fife soil this year (at least that I’m aware of – there might have been more!). So it would seem we’ve had a higher than average occurrence of funnel clouds in Scotland/Fife this summer.
Funnel clouds are not “Tornadoes” in their own right. Technically it can only be called a tornado if the circulation reaches the ground. A large majority of tornadic activity in the UK is not severe in nature but this year there has been damage attributed to tornadoes or severe thunderstorms in various parts of the UK. Sometimes the damage is not caused by the rotating winds, but rather by the sometimes-associated large-sized hail, which can destroy glass houses/conservatories and damage cars over a wide area, or flash flooding.
Funnel clouds generally form out of the motion produced inside a thunderstorm, starting with the convective action inside the storm system. If the right atmospheric conditions are present, an event lower in the atmosphere, such as a passing cold front, can create a situation where a parcel of warm, moist air is forced into a cooler, dryer region of the atmosphere. When this happens, the warm and wet parcel of air starts to rise through the cooler column of air through convection (think of a cork being held under water and then suddenly let go). As the parcel of warm, moist air rises, it starts to get cooled by the surrounding air, which causes the the water vapor in the air to condense and produce heavy rain. Depending on the state of the atmosphere and other factors (such as wind shear), this basic process can eventually lead to the development of thunderstorms.
Sometimes these thunderstorms grow so large, they begin to develop an internal convective “engine” and the storm is able to continue to build. As the rising and falling air within the storm becomes more organised, the central core of the storm can start to rotate, which can eventually lead to the development of a funnel cloud on the underside of the cloud-base(which can in turn “touch down” as a tornado). The physics associated with the entire process is quite complex and the above is a highly simplified version (I don’t pretend to fully understand every aspect!). Indeed tornado development is the subject of much ongoing research in America, and even here in the UK, by organisations such as Torro (TORnado and storm Research Organisation).
The position of the jet stream has tracked further south than usual this summer, for prolonged spells. This has allowed low pressure systems, which spin-up along the track of the jet stream, to bring sweeping weather fronts across the UK. These have often provided the “trigger” to start the convective process, when other atmospheric parameters have been favorable for thunderstorm development. Unfortunately, for the short term at least, it seems that the unsettled weather trend will continue.
So after that explanation, going back to your photographs, the fact you witnessed a funnel cloud does mean there was rotation present, sufficient to produce a funnel cloud which could have extended further to form a tornado, if the conditions were favourable. However as is often the case with UK funnel clouds, there was insufficient energy and organisation within the system to maintain the funnel structure long enough, to allow it to extend to ground level.
We would like to thank Graham for sharing his knowledge and time with us. For those interested to learn more about Graham and the work he does, you can view his websites and projects at:
- Fife Weather: Self built weather station for the Lochgelly area
- Weather Events: The UKs only purpose built mobile weather lab