Tornado Wind Speeds Explained

Wind Speeds by EF Rating

The Highest Wind Speed Ever Measured

On May 3, 1999, during the Bridge Creek-Moore F5 tornado, mobile Doppler radar operated by Dr. Josh Wurman measured winds of 301 mph +/- 20 mph. This remains the highest wind speed reliably measured on Earth in any weather phenomenon.

The measurement was taken about 105 feet above ground level - above the surface friction layer where winds are strongest. Because of the height and instrument uncertainty, the NWS does not use this reading in its official record, but the meteorological community treats it as the reference value.

Second Place: El Reno 2013

The May 31, 2013 El Reno tornado was measured at 296 mph by mobile Doppler radar. Despite this measurement, the tornado was rated EF3 - because the EF Scale is damage-based, and the tornado did not encounter engineered structures capable of showing EF5 damage.

Radar-Measured Winds vs. Damage Ratings

The EF Scale rates tornadoes based on damage, not on measured winds. This means:

• A tornado with 296 mph radar winds can be rated EF3 if damage indicators don't support higher
• A tornado over open country can only be rated EF0 no matter how strong
• Modern Doppler radar sometimes measures winds above what the tornado's damage suggests

Meteorologists frequently debate whether the EF Scale should incorporate radar-measured winds. For now, damage remains the standard.

Sub-Vortex Winds

Multi-vortex tornadoes contain smaller sub-vortices rotating within the parent circulation. Where a sub-vortex overlaps with the parent tornado's peak winds, total wind speed can briefly reach 400+ mph. These localized peaks are what produce the extreme damage patterns seen in Jarrell 1997 and other extreme events.

How Winds Are Measured

Mobile Doppler Radar (DOW)

Research vehicles carrying mobile Doppler radars can measure tornado winds directly from close range. This is how the 301 mph and 296 mph readings were obtained.

Fixed Doppler Radar (NEXRAD)

The national NEXRAD network can detect tornado rotation but not always the peak winds - the radar beam is too far away and too high for most tornadoes.

Damage Surveys

Almost all tornado wind estimates come from post-event damage surveys. Surveyors use the EF Scale's 28 damage indicators to work backward from observed destruction to inferred wind speeds.

Direct Anemometer Measurements

Almost never work. Any weather station in a tornado's direct path is typically destroyed. A handful of measurements have been made by chase-deployed instruments (TIV, TWISTEX probes), but the values are limited.

Wind Speed vs. Damage Threshold

• 65 mph: Loose shingles start peeling
• 90 mph: Mobile homes begin failing
• 110 mph: Trees begin snapping; well-built homes lose windows
• 135 mph: Roofs torn off well-built homes; mobile homes destroyed
• 165 mph: Entire stories of well-built homes destroyed
• 200 mph: Well-built homes leveled off foundations
• 250+ mph: Foundation-sweeping; reinforced concrete failure; asphalt scoured

How Fast Can a Tornado Get?

Theoretical maximum tornado wind speed is somewhere around 350 mph based on the amount of angular momentum available in a supercell mesocyclone. No wind speed above 320 mph has ever been reliably measured. Whether a future tornado will exceed the 1999 Moore record is unknown but not physically impossible.

Compare to Hurricanes

• Category 5 hurricane: 157+ mph sustained wind
• Strongest hurricane ever measured: Patricia 2015 at 215 mph
• EF5 tornado: 200+ mph 3-second gust, potentially 300+ mph

Peak tornado wind speeds substantially exceed peak hurricane wind speeds. However, hurricane winds cover thousands of square miles for hours or days, while tornado peak winds are limited to a small area for minutes.