How to Use the Tornado Simulator
Complete guide to using our tornado simulator: click anywhere to place a tornado, adjust EF rating, path, wind speed, and see real damage estimates for your area.
Quick Start
- Click anywhere on the map - places a tornado at that location
- Adjust wind speed slider - changes EF rating from EF0 to EF5
- Set path length and width - varies the tornado's track
- View results - fatalities, injuries, damage in dollars
Understanding the Results
Fatalities and Injuries
Estimated using peer-reviewed casualty models:
- Simmons & Sutter (2005) - shelter type effect on fatalities
- Ashley (2007) - nighttime tornado 2.5x lethality multiplier
- NOAA data - ~15:1 injury-to-fatality ratio
Structural Damage
Uses HAZUS-MH structure fragility curves - the same tornado wind engineering data FEMA uses. Different structure types have different failure thresholds:
- Mobile homes: ~70% destruction at 100 mph
- Wood frame: ~55% destruction at 150 mph
- Brick masonry: ~35% destruction at 150 mph
- Reinforced concrete: ~30% destruction at 200 mph
Economic Impact
Combines residential loss, infrastructure damage, vehicle destruction, crop losses, livestock, business interruption, and emergency response costs.
Advanced Features
Multi-Segment Paths
Draw a tornado path with multiple points. The simulator will calculate damage for each segment using local population density from that specific county.
Time of Day
Set the tornado to occur at specific times. Nighttime tornadoes will show significantly higher fatality estimates.
Warning Lead Time
Vary the warning lead time from 0 to 60 minutes. Longer warnings reduce fatalities per Simmons & Sutter research.
Structure Mix
Adjust the housing mix in the tornado path - percent mobile homes, wood frame, brick, concrete. Explore how construction quality affects casualties.
Sub-Vortex Boost
Adds intensity peaks matching multi-vortex tornado behavior. Simulates events like Jarrell 1997 or the 1999 Bridge Creek-Moore F5.
Interpret the Results
Compare your simulated tornado to historical events:
- Under 5 killed: Weak or rural event
- 5-25 killed: Moderate event (e.g., Moore 2013 EF5)
- 25-100 killed: Major disaster (e.g., Tuscaloosa 2011)
- 100+ killed: Historic catastrophe (e.g., Joplin 2011)
Use Cases
- Emergency planners - visualize damage scenarios for exercises
- Teachers and students - understand tornado meteorology
- Insurance professionals - model exposure to specific tornado scenarios
- Homeowners - understand what an EF3 vs EF5 could do to your neighborhood
- Storm chasers and meteorologists - explore scenario space
Data Sources
Our simulator uses:
- US Census Bureau ACS 5-Year (2022) - 3,143 US counties
- Statistics Canada 2021 Census - 288 census divisions
- HAZUS-MH - FEMA structural fragility data
- Simmons & Sutter (2005) - casualty models
- Ashley (2007) - nighttime lethality
- NOAA Storm Data - historical event data
What the Simulator Won't Tell You
- Specific individual outcomes - it's a statistical estimate
- Exact building types in your path
- Real-time weather forecasts
- Actual tornado predictions
Do not use the simulator as a substitute for real NWS tornado warnings. If a warning is issued for your area, seek shelter immediately regardless of what any simulator says.
Educational Applications
Teachers using the simulator: consider having students simulate:
- The Joplin 2011 tornado at Joplin's coordinates
- The Bridge Creek-Moore 1999 tornado at Moore
- Multiple locations to compare damage differences by geography
- Different EF ratings on the same location
Try the interactive simulator
Place an EF0–EF5 tornado anywhere in the world and see modeled fatalities, structural damage, and economic loss based on real census data.
Launch simulator →Try the interactive simulator
Place an EF0–EF5 tornado anywhere in the world and see modeled fatalities, structural damage, and economic loss based on real census data.
Launch simulator →