Tornados and Waterspouts
Tornado's
A tornado is a rotating funnel shaped cloud that extends from a Thunderstorm to the ground. When the funnel hits water it’s called a Waterspout. The winds within a tornado can reach 300 mph. The damage paths can be up to a mile wide and possibly up to 50 miles long.
Rain or cloud may hide the Tornado or they maybe clearly visible. It’s possible for Tornado’s to appear transparent until dust and debris is collected or a cloud forms within the structure.
The size of a tornado varies it’s possible that some maybe larger than a mile wide. The forward speed of a tornado maybe nearly zero but may even reach speeds of 70 mph.
While the US is one place most people think of when talking about Tornado’s the UK actually has more per square mile than the USA. An average 30 Tornado’s occur in the UK every year but these are much weaker than US equivalents.
A tornado is only formed when it hits the ground. If it doesn’t it’s called a funnel cloud. The picture below left shows a funnel cloud over the north Midlands.However despite being less powerful than the US equivalents they can still do a fair amount of damage. The picture bottom right shows the damage that happened in Birmingham 2005. This was an F2 Tornado which caused 40 million pounds of damage.
To confuse matters the US and the UK use different scales. The US uses the Enhances Fujitia Scale while the UK uses the T scale also know as the International Tornado Intensity Scale. The T scale was devised by Dr G Terrence Meaden back in 1972. IU've also included that table.
UK Hot Spots
Research by Manchester University produced the following map of UK Hotspots. This clearly shows the further south and east you go the more likely conditions will be more suitable for a formation of such a system
In the UK there is a research group called Torro The TOrnado and Storm Research Organisation who will be able to provide more information.. There web page can be found here http://www.torro.org.uk/
How Tornado's and Waterspouts form
How do Tornado’s form. The ingredients you need are warmth, Moisture, cold dry air above and winds that increase in strength and change direction with height. The updraught then rotates and the storm then becomes a supercell. The image below taken from National geographic shows this pretty well.
The power of a Tornado The Enhanced Fujita Scale
| Enhanced Fujita Scale | |
|---|---|
| Scale | Typical Observations |
| EF-0 | Enhanced Fujita Scale estimated wind speeds: 65 to 85 mph. Typical Observations: Light damage. Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over. |
| EF-1 | Enhanced Fujita Scale estimated wind speeds: 86 to 110 mph. Typical Observations: Moderate damage. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken. |
| EF-2 | Enhanced Fujita Scale estimated wind speeds: 111 to 135 mph. Typical Observations: Considerable damage. Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground. |
| EF-3 | Enhanced Fujita Scale estimated wind speeds: 136 to 165 mph.Typical Observations: Severe damage. Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance. |
| EF-4 | Enhanced Fujita Scale estimated wind speeds: 166 to 200 mph. Typical Observations: Devastating damage. Whole frame houses Well-constructed houses and whole frame houses completely levelled; cars thrown and small missiles generated. |
| EF-5 | Enhanced Fujita Scale estimated wind speeds: Over 200 mph. Typical Observations: Incredible damage. Strong frame houses levelled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (109 yd); high-rise buildings have significant structural deformation; incredible phenomena will occur. |
The International Tornado Intensity Scale
| The International Tornado Intensity Scale | ||||||
|---|---|---|---|---|---|---|
| Scale | Description | Wind Speed (T) | Description of Damage | Track Length | Track Width | Track Area |
| 0 | Light Tornado | 17-24m/s, 39-54mph | Loose light litter raised from ground level in spirals, Tents, marquees, awnings seriously disturbed. Some exposed tiles, slates on roofs dislodged, Twigs snapped; trail visible through crops. Wheelie bins tipped and rolled. Garden furniture & pots disturbed. | ≤215m | ≤2.1m | ≤464㎡ |
| 1 | Mild Tornado | 25-32m/s, 55-72mph | Deck chairs, small plants, heavy litter becomes airborne, Minor damage to sheds, More serious dislodging of tiles, slates, Chimney pots dislodged. Wooden fences flattened, Slight damage to hedges and trees, Some windows already ajar blown open breaking latches. | 216m-464m | 2.2m-4.6m | 465-2150㎡ |
| 2 | Moderate Tornado | 33-41m/s, 73-92mph | Heavy mobile homes displaced. Light caravans blown over, Garden sheds destroyed, Garage roofs torn away and doors imploded, Much damage to tiled roofs and chimneys, Ridge tiles missing, General damage to trees, some big branches twisted or snapped off, small trees uprooted, Bonnets blown open on cars, Weak or old brick walls toppled, Windows blown open or glazing sucked out of frames. | 465m-999m | 4.7m-9.9m | 2160-9990㎡ |
| 3 | Strong Tornado | 42-51m/s, 93-114mph | Mobile homes overturned / badly damaged. Light caravans destroyed, Garages and weak outbuildings destroyed, House roof timbers considerably exposed, Some of the bigger trees snapped or uprooted, Some heavier debris becomes airborne causing secondary damage breaking windows and impaling softer objects, Debris carried considerable distances, Garden walls blown over, Eyewitness reports of buildings physically shaking, Mud sprayed up the side of buildings. | 1.0km-2.1km | 10m-21m | 0.01-0.046㎢ |
| 4 | Severe Tornado | 42-51m/s, 93-114mph | Motorcars levitated. Mobile homes airborne / destroyed, Sheds airborne for considerable distances. Entire roofs removed from some houses, Roof timbers of stronger brick or stone houses completely exposed, Gable ends torn away, Numerous trees uprooted or snapped. Traffic Signs folded or twisted, Some large trees uprooted and carried several yards, Debris carried up to 2km leaving an obvious trail. | 2.2km-4.6km | 22m-46m | 0.047-0.21㎢ |
| 5 | Intense Tornado | 62-72m/s, 137-160mph | Heavier motor vehicles (4x4, 4 Tonne Trucks) levitated, Wall plates, entire roofs and several rows of bricks on top floors removed, Items sucked out from inside house including partition walls and furniture, Older, weaker buildings collapse completely, Utility poles snapped. | 4.7km-9.9km | 47m-99m | 0.22-0.99㎢ |
| 6 | Moderately-Devastating Tornado | 73-83m/s, 161-186mph | Strongly built houses suffer major damage or are demolished completely, Bricks and blocks etc. become dangerous airborne debris, National grid pylons are damaged or twisted, Exceptional or unusual damage found, e.g. objects embedded in walls or small structures elevated and landed with no obvious damage. | 10km-21km | 100m-215m | 1.0-4.6㎢ |
| 7 | Strongly-Devastating Tornado | 84-95m/s, 187-212mph | Brick and Wooden-frame houses wholly demolished, Steel-framed warehouse-type constructions destroyed or seriously damaged, Locomotives thrown over, Noticeable de-barking of trees by flying debris. | 22km-46km | 216m-464m | 4.7-21㎢ |
| 8 | Severely-Devastating Tornado | 96-107m/s, 213-240mph | Brick and Wooden-frame houses wholly demolished, Steel-framed warehouse-type constructions destroyed or seriously damaged, Locomotives thrown over, Noticeable de-barking of trees by flying debris. | 47km-99km | 465m-999m | 22-99㎢ |
| 9 | Intensely-Devastating Tornado | 108-120m/s, 241-269mph | Many steel-framed buildings demolished, Locomotives or trains hurled some distances, Complete debarking of any standing tree-trunks, Inhabitants survival reliant on shelter below ground level. | 100km-215km | 1.0-2.1km | 100-464㎢ |
| 10 | Super Tornado | 121-134m/s, 270-299mph | Entire frame houses and similar buildings lifted bodily from foundations and carried some distances, Destruction of a severe nature, rendering a broad linear track largely devoid of vegetation, trees and man made structures. | 216km-464km | 2.2-4.6km | ≥465 |