By:
Bob Henson
4:03 PM GMT on March 26, 2015
Two Oklahoma suburbs took the brunt of damage from a rapid-fire severe weather outbreak that developed Wednesday afternoon. At least one person was killed and another critically injured when a tornado and/or accompanying downdraft winds
moved across a manufactured home park in Sand Springs, just west of Tulsa. A number of mobile homes were reportedly destroyed in the high winds. Just south of Oklahoma City, the long-suffering town of Moore--struck by catastrophic F5/EF5 tornadoes in 1999 and 2013 and a deadly tornado that produced F3 damage in Moore in 2003--experienced
yet another twister, though fortunately a much weaker one than its predecessors. Overall, the severe weather on Wednesday covered a swath from central Oklahoma to southeast Missouri, producing
a preliminary count of 8 tornadoes and more than 110 reports of severe hail, some as large as baseballs.
Figure 1. First responders work to free a man from a pile of rubble after a round of severe weather hit a trailer park near 145th West Avenue and West 17th Street in Sand Springs, Okla., Wednesday, March 25, 2015. (AP Photo/Tulsa World, Matt Barnard)
Wednesday’s damage in Sand Springs is a painful reminder of our lack of national policy on mobile home safety in tornadoes. Winds of no more than 110 mph (a
borderline EF1/EF2 on the Enhanced Fujita Damage Scale) can
destroy the roof and walls of a typical manufactured home, or cause it to roll over. Although
just 5% of Americans live in mobile homes, anywhere from 25% to 50% of tornado-related deaths in a typical year occur in such homes, including 17 of 47 U.S. deaths
in 2014, 17 of 55 deaths
in 2013, and 48 of 68 deaths
in 2012, according to data from NOAA’s Storm Prediction Center. Thousands of mobile home residents live on acreages with no ready source of safe shelter, but even those who live in mobile home parks often lack an underground refuge. Although
the state of Minnesota and some localities mandate shelters, safe rooms, and/or an evacuation plan when mobile home parks reach a certain size, there is no such national requirement. Where shelters do exist, they often fall prey to vandalism or are used for other purposes. One Sand Springs resident told the Tulsa World that as Wednesday’s tornado bore down, she discovered that her RV park’s designated shelter was
“full of washing machines”.
Figure 2. The paths of the Moore, Oklahoma tornadoes from May 3, 1999 (green); May 8, 2003 (blue); and May 20, 2013 (red), together with the preliminary path of the March 25, 2015 tornado (yellow). This year’s tornado crossed the path of the 1999 tornado near the northwest edge of Moore and intersected the 2013 path near Interstate 35. Image credit:
NWS/Norman and
NWS.
Few if any cities have experienced the kind of protracted bad luck with tornadoes that Moore has had to deal with (see Figure 2). The city endured major twisters on
May 3, 1999 (killing 36 and injuring 583 along its full path);
May 8, 2003; and
May 20, 2013 (killing 24 and injuring 377 along its full path). Wednesday’s tornado was
far less destructive, mostly knocking out windows and destroying carports and trees, although it blew over some vehicles and
knocked out the three transmission towers of the radio station KOKC (formerly KOMA, which broadcast from a separate tower in the mid-1950s that was the world’s largest structure at the time).
TWC's Jon Erdman has a nice article on the
Moore and Oklahoma City Tornado History.Bob Henson