It’s well-known that Texas is part of Tornado Alley, but are some counties more vulnerable than others?
An EF-4 tornado that hit Alabama on March 3, killing 23 people, inspired 19-year-old meteorology student Ethan Rogers to create his Tornado Vulnerability Index, according to The Washington Post.
Rogers, who attends Penn State University, used data from the Census Bureau and the National Weather Service to create a map of which U.S. counties have the most tornadoes, which experience the most intense tornadoes and where tornadoes can cause the most damage.
“I asked myself the question of who is most at risk to these types of tornadoes,” Rogers told the newspaper. “So many of those casualties were people who did not have a lot of money or lived in a mobile-home park.”
To create the index, Rogers analyzed four factors and weighed them equally: mean tornado frequency and intensity, population density, mean household income and mobile-home concentration.
"I picked all of these metrics because I believe that each one of them plays a major role in how much life and property is lost in the event of a tornado," Rogers told The Post. "The problem is not just a meteorological problem, it's also socioeconomic. Those who are poor and who can't afford houses that are structurally sound — or have basements or even shelters — are in much more danger."
So which North Texas counties are most vulnerable to twisters?
Dallas, Tarrant, Parker and Johnson counties all are considered highly vulnerable by the index.
From 1880 through June 19, the three counties are neck and neck in their tornado counts: Johnson County has 106 tornadoes on record, Dallas County has 101 and Tarrant County has 100, according to the weather service. Parker County has had 68.
Denton and Collin counties were labeled as moderately vulnerable in the index. In that same time span, Denton County has had 62 tornadoes and Collin 57.
With four tornadoes, Tarrant County has had the most so far this year, followed by Denton County with three, Dallas County with two. Collin County has had none.
North Texas has seen more severe weather than usual this year — especially during June, when severe weather typically dies down. The National Weather Service's office in Fort Worth has issued more severe weather warnings this month — 84 through Sunday — than in any other June since 2009, according to meteorologist Tom Bradshaw.
KXAS-TV (NBC5) chief meteorologist Rick Mitchell said a lingering El Niño this summer could be the driving force behind above-average rainfall and chances for more severe weather.
