Dec 21, 2010
Tornadoes are nature’s most violent storms and is categorized as a violently rotating column of air extending from a thunderstorm to the ground. Typically tornados appear as rotating, funnel like clouds which extends from within a thunderstorm to the ground. Pretty to look at but devastating on nature with severe winds which can reach speeds of 300 miles per hour. Studies have shown that Tornadoes are more likely to form between the hours of 3pm and 9pm although it the results are caveated in that tornados can occur at any time and occasionally, tornadoes develop so quickly that little, if any at all, advance warning is possible.
The average advancing speed of a tornado is around 30mph however this can vary
significantly from an almost motionless speed to acceleration of up to 70mph in addition to rotating winds in excess of 250mph. If these forces of nature were not enough, a strong Tornados can also accompany tropical storms and hurricanes as they begin to move onto land.
So what causes Tornados?
Tornados are caused by cold and warm air joining together violently including fronts, lows, highs, and prevailing wind patterns. The arch nemesis of the Tornado, the Supercell often forms from a regular thunderstorm, although can be generated independently. Supercells in contrast typically produce substantial amounts of rain, severe winds,
enormous air downdrafts, hail, as well as tornadoes themselves.
Tornado Watches and their immediate alerts signify that there is a potential of tornadoes forming in the local area. Individuals within a particular watch area when notified of a tornado should be ready to react quickly should a warning be issued or if they believe that a tornado is approaching. In most countries where tornados and
hurricanes are prevalent National Weather Services typically issue tornado
watches/alerts whenever tornadoes are possible within the local vicinity. Being prepared for these alerts is crucial and it is recommended that individuals whom reside in high risk areas should review their disaster plans to include the safety and location of family members, access to radio or televisions well before any alerts are issued.
Under typically circumstances, ocean water needs to achieve a temperature above 79 degrees for a hurricane to form, as a consequence, Hurricanes generally develop during the late summer months into the early fall when atmospheric and water temperature conditions are at their optimal. Hurricanes and tropical storms can also help develop
microburst’s, and storm surges which is effectively a rapid rise in water levels which is generated from the winds pushing the water inland. These and storm surges which impact coastal regions, cause extensive damage from heavy rainfall. Although
immensely powerful a beautiful sight is the tranquil centre of a hurricane named the eye, this is one of the most
recognisable aspects of these storms being a very distinctive picture within the many satellite images taken during the storm seasons.
- Category Five – sustained winds of 156mph +
- Category Four – sustained winds from 131 to 155mph
- Category Three – sustained winds of up to 111?130mph
- Category Two – sustained winds of up to 96?110mph
- Category One – sustained winds of up to 74?95mph