The twister in the talehttps://indianexpress.com/article/news-archive/print/the-twister-in-the-tale/

The twister in the tale

Three storm chasers died chasing the tornado that tore through Oklahoma last week,caught in a bumper-to-bumper snarl of storm chasers and their vehicles. With storm chasers exploding on the scene,the question scientists are asking—are they furthering science or just seeking a churning thrill?

Who are storm chasers?

Scientists,meteorologists,forecasters,weather reporters,extreme weather enthusiasts interested in understanding and forecasting tornadoes,super storms and hurricanes. For most chasers only 1 in 5 or 10 trips results in tornado sighting

The 1996 flick Twister and the Nat Geo TV show such as Storm Chasers have inspired hundreds of people to chase storms from March to July in the Tornado Alley of US

First storm chasers

Roger Jensen,believed to be the first storm chaser,chasing tornadoes in the 1940s. Jensen’s big tornado moment was on June 28,1975 when he captured a barrel-shaped tornado in Minnesota. The tornado was rated F-2 on the Fujita measurement scale

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David Hoadley,(in pic) the ‘pioneer’ storm chaser,chasing storms since 1956. He founded Storm Track in 1977,a newsletter to connect the chaser community. He’s seen 200 tornadoes and travelled 12,10,000 km chasing storms

AND THE STORMs THEY CHASE

Not fully understood,tornadoes usually form from huge super-cell thunderstorms that take shape when warm,moist air from Gulf of Mexico meets cold,dry air from the Arctic

Air rises from the ground moving slowly to the bottom of a thunderstorm cloud

Changing wind speeds cause air to rotate vertically creating a vortex or mesocyclone

The funnel created by the vortex at the ground forms the cloud base

Funnel spins at tremendous speeds,transparent at first,getting visible as it picks debris on its path

Gearing up

Doppler on wheels: Mobile weather radars that put instruments into supercell thunderstorms. Can scan tornadoes,make 3D maps of wind and debris. DOWs have mapped out multiple vortices,debris clouds,and the genesis of tornadoes

VORTEX 2: The Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2) is the largest tornado research project in history to explore how,when and why tornadoes form. When V2,with a fleet of 40+ vehicles,pulled into small towns in the US,they more than doubled the population

TAKING MEASURE

Tornadoes have occurred on every continent,except for Antarctica

United States records 1,200 tornadoes a year. Canada is a distant second with 100 tornadoes a year

Current tornado warnings have a 13-minute average lead time and a 70 per cent false alarm rate

Tornadoes last from several seconds to more than an hour. Most tornadoes last less than 10 minutes

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The deadliest tornado in US history was in 1925,when a tornado ravaged Missouri,Illinois,and Indiana moving at 97 to 113 kmph—twice the forward speed of a tornado. 2,000 people were injured and over 700 people died

Compiled by Priyanka Kotamraju