(WWLP) – The June 1, 2011 tornado caused a lot of damage across the Pioneer Valley. 22News Storm Team Meteorologist Allison Finch breaks down how tornados form and how fast their wind speeds can get.
Most to all tornadoes form from thunderstorms. Within a thunderstorm, on the surface, or ground, winds are fairly light but once you get into the atmosphere and closer to the cloud base, the winds are stronger and faster.
The difference between the speed and heights of the wind is called wind shear. This difference actually helps create a rotating column of air, which spins horizontally. The updraft or upwards current of air from the thunderstorm takes this rotating column of air and makes it vertical, creating a column of air embedded within a thunderstorm.
This vertical rotation will then start to form a wall cloud, which will look like it is rotating from the ground. From this wall cloud, a funnel cloud is formed. This is the long column of air coming down from a thunderstorm. It is not considered to be a tornado until the funnel cloud makes contact with the ground. Once it makes contact with the ground, a tornado can last from a few seconds to hours, but on average they only last 10 minutes.
There are different classifications of tornado wind speeds. We classify them on the Enhanced Fujita Scale, which ranges from zero to five. EF0 and EF1 tornadoes are considered “weak” and have wind speeds of 65 to 110 mph. EF2 and EF3 tornadoes are considered “strong” and have wind speeds of 111 to 165 mph. Lastly, EF4 and EF5 tornadoes are considered “violent” and have wind speeds of 166 to 200 mph or more.
The Springfield tornado in 2011 was classified as an EF3 tornado and it had wind speeds of up to 160 mph.
All of these steps can happen within a matter of minutes, so it is important to stay weather-ready when severe weather hits.