EF Scale for TORNADO Damage FUJITA SCALE DERIVED EF SCALE OPERATIONAL EF SCALE F Number Fastest 1/4-mile (mph) 3 Second Gust (mph) EF Number 3 Second Gust (mph) EF Number 3 Second Gust (mph) 0 40-72 45-78 0 65-85 0 … Continue reading Tornado EF Wind Scale