Doppler Radar Indicated Tornadoes - The "Hook Echo"

During tornadic events, it is very common to hear "National Weather Service Doppler radar indicated a severe thunderstorm capable of producing a tornado." One of the signatures of a developing tornado is a "hook echo" on radar. The hook on radar is caused by rain, hail or debris being wrapped around rotation. A tornado may be forming, or already be formed.

On January 7th, 2008 at around 6:05pm, an EF-2 tornado with windspeeds around 125 MPH touched down in Republic, MO. The below image is the hook echo on radar from 6:00pm as the storm is entering the city limits of Republic. If you click on this image, you will get a pop-out image that you can mouse over and see roads and cities in relation to the hook echo.

As you can see by the mouse over, highly populated areas of Springfield were spared as this tornado moved northeast and lifted over the city. Unfortunately, other areas were not so fortunate. This is the storm that caused two fatalities in the Strafford and Marshfield area after hitting Republic and lifting over Springfield.

Note: The dark circle in the middle is the center of the radar site near at the National Weather Service by the Springfield-Branson Regional Airport.

Click on image to see a mouse-over version with roads and cities.

-- Jeff - KB0WVT