Tuesday, 10 June 2008
Tornado alley
Some of the worst ever tornadoes have been whirling very close to the city of Chicago these last few days. Five smashed through the southern suburbs on Saturday evening with winds between 111 to 135 mph turning trucks over, tearing of roofs and knocking down walls.
Tornadoes are ranked from F0 to F5. Wind speeds of a F0 are between 40-72mph and a F5 has a ferocity of a scary 261mph to 318mph. Only once did Chicago suffer a F5 and that was in 1990 when a tornado formed to the south-west of the city and killed 29 people and caused $165m of damage.
Tornadoes develop several thousand feet above the earth's surface inside a severe rotating thunderstorm, known as a supercell thunderstorm. The tornado is basically a violently rotating column of air which descends from a thunderstorm to the ground actually only touching land for two to three minutes at a time. No other weather phenomenon can match the fury and destructive power of tornadoes.
The weekend's tornadoes were ranked as F2's. South of Chicago on the border of Indiana, a dozen homes in Richton Park were heavily damaged, the I57 was shut following a massive vehicle pile up, five steel transmission towers supporting high-voltage power lines, were severely damaged by the storm leaving hundreds of thousands of homes without power and severe flooding is crippling parts of Indiana
On Sunday further thunderstorms came through the Chicago area. I was sat at home watching the wind push the rain horizontally past my balcony. 60mph winds were recorded in the city and on the west side. The storm pushed Lake Michigan water ahead of it so that lake levels dropped by about 2 feet, triggering a warning from the weather service of possibly dangerous conditions when the water came sloshing back, an effect called a seiche.
According to the weather service, 112 people have died in tornadoes since the beginning of the year, the most in the United States in a decade.
A history of Chicago Tornadoes: NOAA ¶ 16:12
Some of the worst ever tornadoes have been whirling very close to the city of Chicago these last few days. Five smashed through the southern suburbs on Saturday evening with winds between 111 to 135 mph turning trucks over, tearing of roofs and knocking down walls.Tornadoes are ranked from F0 to F5. Wind speeds of a F0 are between 40-72mph and a F5 has a ferocity of a scary 261mph to 318mph. Only once did Chicago suffer a F5 and that was in 1990 when a tornado formed to the south-west of the city and killed 29 people and caused $165m of damage.
Tornadoes develop several thousand feet above the earth's surface inside a severe rotating thunderstorm, known as a supercell thunderstorm. The tornado is basically a violently rotating column of air which descends from a thunderstorm to the ground actually only touching land for two to three minutes at a time. No other weather phenomenon can match the fury and destructive power of tornadoes.
The weekend's tornadoes were ranked as F2's. South of Chicago on the border of Indiana, a dozen homes in Richton Park were heavily damaged, the I57 was shut following a massive vehicle pile up, five steel transmission towers supporting high-voltage power lines, were severely damaged by the storm leaving hundreds of thousands of homes without power and severe flooding is crippling parts of Indiana
On Sunday further thunderstorms came through the Chicago area. I was sat at home watching the wind push the rain horizontally past my balcony. 60mph winds were recorded in the city and on the west side. The storm pushed Lake Michigan water ahead of it so that lake levels dropped by about 2 feet, triggering a warning from the weather service of possibly dangerous conditions when the water came sloshing back, an effect called a seiche.
According to the weather service, 112 people have died in tornadoes since the beginning of the year, the most in the United States in a decade.
A history of Chicago Tornadoes: NOAA ¶ 16:12
