I was watching ABC news about the 900 mile swath of 21 tornadoes that were active from western Michigan to Missouri last night and remembered watching a special on TV about one of climatologist’s biggest fears, tornadoes that unite to become multi-vortex mega storms. Is this what we’re beginning to experience? The NOAA website reports: “There is a statistical trend (as documented by NSSL’s Harold Brooks) toward wide tornadoes having higher damage ratings. This could be related to greater tornado strength, more opportunity for targets to damage, or some blend of both. However, the size or shape of any particular tornado does not say anything conclusive about its strength.” So there is a trend but it appears to be downplayed, while tornadoes are becoming rampant across the heartland of our country, destroying more and more properties every year, and occurring out of season.
Residents in the Missouri area said they witnessed 4 distinct heads of the multi vortex tornado that covered a 5-mile swath of land. This tornado was also described by the newscaster as a bouncer, touching down, going up, and then touching down again. The same NOAA website states that tornadoes don’t literally skip. It says: “By definition [] a tornado must be in contact with the ground. There is disagreement in meteorology over whether or not multiple touchdowns of the same vortex or funnel cloud mean different tornadoes (a strict interpretation). In either event, stories of skipping tornadoes usually mean
1. There was continuous contact between vortex and ground in the path, but it was too weak to do damage;
2. Multiple tornadoes happened; but there was no survey done to precisely separate their paths (very common before the 1970s); or
3. There were multiple tornadoes with only short separation, but the survey erroneously classified them as one tornado.
So was this multi-vortex, bouncing tornado possibly a new phenomena? Is there anything that can be done to limit the increasing velocity and strength of tornadoes? Well, “Daniel Barrie and Daniel Kirk-Davidoff of the University of Maryland concocted an experiment. They took the pattern of expanding turbine fields to an extreme, and used a computer model to calculate what might happen if all the land from Texas to central Canada, and from the Great Lakes to the Rocky Mountains were covered in one massive wind farm,” according to an article on Discovery Channel website. It said, “[They] acknowledged the hypothetical wind farm was far larger than anything humans are likely to build. But meeting the Department of Energy’s goal of wind power generation by 2030 would require that scores of huge wind farms be built throughout the Midwestern United States. The total disturbance caused by turbines could be enough to steer storms.”
Interesting!
Although the NOAA website states that it is unlikely we could ever come up with anything that could stop a tornado that wouldn’t be worse than the tornado itself, it does talk about dissipating one, which means to slow down or cause it to break up. The website’s FAQ’s page said that tornadoes do need a source of instability and a “larger-scale property of rotation (vorticity) to keep going.” It went on to say that a lot of processes surrounding a storm could rob the area around a tornado of either instability or vorticity. Cold outflow is one. This is the flow of wind out of the precipitation area of a shower or thunderstorm. It’s been observed that cold outflow causes a tornado to go away. It also says: “For decades, storm observers have documented the death of numerous tornadoes when their parent circulations (mesocyclones) weaken after they become wrapped in outflow air — either from the same thunderstorm or a different one.”
Could that different outflow of air possibly be produced by large wind farms in the near future? Could they produce enough wind to replicate the outflow air of a thunderstorm? If so, it’s incentive enough to develop wind power. There are far too many homes and properties destroyed every year from increasingly bad weather. If we thought the stock market dive was bad, imagine insurance companies going bust?
http://abcnews.go.com/US/wireStory?id=7582543
http://dsc.discovery.com/news/2008/11/25/wind-farms-weather.html
