Arguably, the most intense weather event that takes place on Earth is the rare occurence of a tornado that reaches EF strength on the Enhanced Fujita Scale or F5 on the original Fujita Tornado Damage Scale. Winds within these monsters have been measured as high as mph by Doppler radar Bridge Creek, Oklahoma, on May 3, , pictured above but winds likely have exceeded mph on other occasions in tornadoes that were not so closely observed.
The United States and Canada are the only countries in the world to have verified reports of tornadoes with a classification of F5 or EF5 strength. The reason for this lies with North America's unique topography. Only in North America does a solid land mass stretch from the subtropics to the arctic with no mountain barriers to inhibit the mixture of air masses from these two regions. When the conditions are just right normally in the spring extraordinary supercells can develop in the central portion of the country and can occasionally spin out a tornado of EF5 intensity.
The "single" deadliest tornado in U. At least people died in Missouri, Illinois and Indiana when a F5 mile-wide monster carved a course that was apparently miles through the three states. Modern research, however, suggests that this was likely a series of tornadoes developing from a single supercell traversing the area.
Other oddities include two cities that were struck twice: Waco, Texas and Moore, Oklahoma. Waco, TX had F5 tornadoes in killing and in May on the ground only yards and causing no injuries or fatalities. Moore, Oklahoma a suburb of Oklahoma City has also been hit twice and both twisters were devastating.
Moore was hit in May 36 killed and again in May 24 killed. Just like the long major hurricane U. The last EF-5 tornado to hit the U. There will be another one, but one good thing about these huge tornadoes is that they are easy to warn for, easy to see on Doppler radar and they usually come with a strong dynamic weather system that can be forecast days in advance. Meteorologists from the National Weather Service survey areas where tornado damage has occurred.
They then use the Enhanced Fujita Scale to estimate the maximum winds in the tornado. Daily 12 Today. Tornado Central. The last EF5 tornado in the U.
However, we can assume that the strength of F5 and EF5 tornadoes is roughly comparable; only the estimated wind speeds have changed. The acknowledged world expert on tornado history is independent researcher Thomas P. He is an acolyte of the famous University of Chicago researcher Theodore Fujita, the pioneer of modern tornado science and the one who developed the original F-scale in Grazulis is the author of the epic page book Significant Tornadoes: updated through in an addendum. In the first table below, I list all of the tornadoes from to that Grazulis has classified as F5 strength and described in detail in his book.
Only about 0. However, the s, s, and s seem to be especially active for violent tornadoes. Could it be that when the NWS began classifying tornadoes by the F-scale, it was not as stringent in its damage analysis as it has since been over the past four decades? There is some evidence to support this idea, according to Dr. Harold Brooks, an expert on tornado climatology at the University of Oklahoma.
Brooks said in an email that the initial F-scale ratings for most tornadoes from through were done by students hired in the summer of They were given the text description of the damage and Fujita's canonical pictures and text description of the damage scales.
It appears they overrated the tornadoes, relative to the ratings. Brooks and Jeffrey Craven showed that the number of U. At least people died in Missouri, Illinois, and Indiana when a F5 mile-wide monster carved a course that was apparently miles through the three states. Modern research, however, suggests that this was likely a series of tornadoes developing from a single supercell traversing the area.
0コメント