The massive tornado that struck Moore, Oklahoma, on Monday was the fourth significant tornado to hit that city during the past 14 years, each during the month of May<\/p>\n
Moore, a city of some 55,000 people, is a suburb of Oklahoma City, which lies directly in the bull\u2019s eye of what is referred to as Tornado Alley, the area of the country most prone to producing tornadoes.\u00a0 Historically, Oklahoma City has had more tornado strikes than any other city in the United States, and many of those strikes have been large and deadly. \u00a0Within the past 14 years, Moore has been struck four times, each time during the month of May:\u00a0 May 3, 1999, May 8, 2003, May 10, 2010, and May 20, 2013.<\/p>\n
Monday\u2019s tornado was massive, measuring more than a mile wide, and was initially given a preliminary rating of EF-4 on the Enhanced Fujita Scale<\/a>.\u00a0 On Tuesday, however, the National Weather Service<\/a> upgraded its rating to an EF-5, the highest category on the scale, with minimum wind speeds of at least 200 mph.<\/p>\n Tornadoes are rated by the type of damage they produce (their \u201cstrength\u201d).\u00a0 Those rated in the EF-3 to EF-5 categories are considered to be the most \u201cviolent,\u201d seemingly able to bend the laws of physics\u2014pushing straws through thick tree trunks or scouring homes down to their foundations while leaving something as fragile as a small glass vase untouched in the same area.\u00a0 Fortunately, these types of monster storms are fairly rare.<\/p>\n According to NOAA\u2019s National Climatic Data Center<\/a>, an average of 1,253 tornadoes occur in the U.S. every year, with most of these tornadoes being categorized as \u201cweak\u201d (EF-0 to EF-1).\u00a0 \u201cThe remaining small percentage of tornadoes are categorized as violent (EF-3 and above).\u00a0 Of these violent twisters, only a few (0.1 percent of all tornadoes) achieve EF-5 status, with estimated winds over 200 mph and nearly complete destruction.\u201d\u00a0 Given these statistics, about 20 tornadoes per year \u201ccan be expected to be violent and possibly one might be incredible (EF-5).\u201d<\/p>\n Unfortunately for Moore, the \u201cincredible\u201d has now happened twice in 14 years, with the second EF-5 occurring Monday.\u00a0 Since the 1950s, there have been only 59 EF-5 tornadoes in the U.S.\u00a0 Moore now has the distinction of having been hit by two of those EF-5 tornadoes.<\/p>\n Many people in Moore who experienced the previous May 3, 1999, monster EF-5 tornado said that Monday\u2019s tornado \u201cappeared to be even worse.\u201d \u00a0The May 3, 1999, EF-5 tornado was also a mile wide, and produced an approximate recorded near-surface wind speed of 318 mph<\/a>, the highest winds ever recorded.\u00a0 And like the May 3, 1999, monster EF-5, Monday\u2019s tornado also tracked along a similar path.<\/p>\n So what is it about Moore that makes it so susceptible to such intense, violent storms?\u00a0 Could it all just be horrific coincidence or could it be its location?<\/p>\n Oklahoma leads the nation in the number of violent tornadoes per year, and Moore is situated within the crosshairs of Tornado Alley, which experiences more tornadoes than anywhere else in the world.\u00a0 During spring in this region, conditions are ideal for spawning tornadoes.\u00a0 Moist, warm air is drawn north from the Gulf of Mexico where it meets dry air coming down from the Rocky Mountains, which \u201clifts\u201d it aloft.\u00a0 The clash of these different types of air masses creates atmospheric instability which can produce dangerous supercell thunderstorms.\u00a0 Supercells contain deep rotating updrafts called mesocyclones, which can and often do produce tornadoes.\u00a0 Considering all of these factors, it becomes easier to understand why this area is so susceptible to such violent storms.<\/p>\n Robert Henson<\/a>, a science journalist and meteorologist working as an editor and writer at the National Center for Atmospheric Research<\/a> in Boulder, Colorado, says that \u201cIt\u2019s just the flat prairie of Oklahoma, with no particular features.\u00a0 Nobody\u2019s established in science why one spot gets hit more than another.\u00a0 This is simply the terrible luck of the draw.\u201d \u00a0\u00a0And for Moore, Oklahoma, that \u201cterrible luck of the draw\u201d played out on Monday.<\/p>\n