On June 9, 2019 several landspout tornadoes formed over Northeast Iowa near Cedar Rapids. NWS Quad Cities has listed these as EF0 tornadoes with max winds of 50 mph. However I'm under the impression that EF0 starts at 65 mph, so does anyone have any speculation as to how a tornado can be an EF0 with estimated winds below 65 mph?
Mods: I'm not sure whether this belongs in introductory or advanced weather. Feel free to move it to the correct section if need be.