Deadly El Reno tornado downgraded

Watch: El Reno tornado caught on camera (May 31)

TORONTO – The May 31 tornado that killed eight people including three professional storm chasers in El Reno, Okla., has been downgraded from an EF5 to an EF3.

The National Oceanic and Atmospheric Administration (NOAA) made the decision after surveying the damage.

Tornadoes are classified on the Enhanced Fujita (EF) scale based on the damage caused by its winds. Winds on the scale range from EF0 to EF5.

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Why the downgrading of the tornado?

“Despite the radar-measured wind speeds, the survey team did not find damage that would support a rating higher than EF3.”

Though NOAA considers mobile radar reliable, the National Weather Service (NWS) policy is to base EF ratings on the amount of damage on the ground.

The NWS is a branch of NOAA.

Pirtle said that NWS is exploring revising its policy to allow the use of experimental radar data in the future.

The El Reno tornado was responsible for killing veteran tornado chasers, Tim Samaras, his son Paul, as well as Carl Young. The tornado goes down as the widest tornado in U.S. history, measuring 42 km across.