The tornado that struck El Reno, Oklahoma, on the evening of May 25, 2019, was officially classified as an EF3 on the Enhanced Fujita scale. This rating signifies a powerful storm capable of causing severe damage, but it is not determined by simply measuring wind speed. The final EF3 designation resulted from a precise, post-disaster evaluation of the destruction left along the storm’s path. Trained surveyors use a standardized scientific process to analyze structural destruction and match the observable damage to an estimated wind speed range.
Understanding the Enhanced Fujita Scale
The Enhanced Fujita (EF) scale is the standardized system used in the United States to rate the intensity of tornadoes. This scale does not measure a tornado’s wind speed directly but instead estimates it based on the damage observed after the storm has passed. It is a damage scale, ranging from EF0 (light damage) to EF5 (incredible damage).
The EF scale employs a detailed system that uses 28 different Damage Indicators (DI), which represent various types of structures or objects. These indicators include mobile homes, residences, shopping malls, schools, and trees. Each Damage Indicator is then assigned a Degree of Damage (DOD) from a set of defined criteria, which describes the level of destruction observed.
This DI and DOD combination provides a range of estimated wind speeds for the damage at that specific point. For instance, an EF0 rating corresponds to estimated three-second wind gusts of 65 to 85 miles per hour (mph), while an EF5 rating indicates winds exceeding 200 mph. The EF3 category, the rating assigned to the El Reno tornado, is associated with wind speeds estimated to be between 136 and 165 mph.
The EF scale represents an improvement over the original Fujita scale because it accounts for construction quality and variability. This refinement ensures that the destruction of a poorly constructed building is not automatically rated the same as a well-built structure sustaining similar damage. The final EF rating assigned to a tornado is based on the highest wind speed estimate found anywhere along its track.
The Path and Impact of the Specific Tornado
The May 2019 El Reno tornado was a compact and short-lived event that occurred as part of a larger severe weather outbreak across the Plains. It touched down quickly late on a Saturday night, around 10:28 p.m. local time, embedded within a squall line.
The tornado’s path was short, extending only about 2.2 miles across the southern part of the city. At its widest point, the circulation was measured at a narrow 75 yards across. Despite its limited size and duration of only four minutes on the ground, the tornado struck a densely populated commercial area.
The storm’s worst damage concentrated around the intersection of Interstate 40 and Highway 81. This area included the American Budget Value Inn motel and the adjacent Skyview Estates mobile home park. The tornado’s impact was immediate and tragic, resulting in two fatalities and injuring 29 people.
The storm’s high winds and rapid onset caused catastrophic damage to the motel and completely destroyed numerous mobile homes. This sudden, nocturnal strike on occupied structures provided the localized physical evidence needed for the official rating determination.
Damage Indicators Used for the EF3 Rating
The official EF3 rating was assigned because the damage observed by National Weather Service survey teams met the criteria for estimated wind speeds between 136 and 165 mph. The most compelling evidence came from the destruction of the two-story American Budget Value Inn motel near the interstate.
The observed destruction of the two-story American Budget Value Inn motel met the Degree of Damage criteria for EF3 winds, serving as a key Damage Indicator for a small commercial building. Surveyors noted that the second story of the motel was largely leveled, with exterior walls collapsing. This level of damage, where a significant portion of the structure is destroyed but the foundation is not swept clean, is a clear marker for the EF3 category.
The motel’s partial collapse demonstrated the severe force required to compromise the structural integrity of a permanent building. Furthermore, the adjacent Skyview Estates mobile home park suffered near-total devastation. The complete destruction of these mobile homes provided additional confirmation of high-end EF2 to low-end EF3 wind speeds in that area.
The tornado also heavily impacted a nearby car dealership. Vehicles were tossed and severely damaged, and the building sustained significant structural damage, including the loss of roof structure and exterior walls. The combination of the motel’s structural failure, the devastation of the mobile home park, and the commercial property damage all consistently pointed to peak wind gusts within the 136 to 165 mph range.
The evidence did not support an EF4 rating, which requires more extreme damage. An EF4 classification typically involves well-built homes being completely leveled or the destruction of substantial commercial structures down to the ground level. Since the heaviest destruction centered on the collapse of the motel’s upper story and the destruction of less-resilient structures, the EF3 rating accurately reflected the most intense, verifiable damage observed along the path of the 2019 El Reno tornado.