Tornado chart is used to Sensitivity Analysis. It is one of the tools in Quantitative Risk Management phase of Risk Management. A good introduction about Tornado Chart is at https://en.wikipedia.org/wiki/Tornado_diagram
The Tornado Chart template can be download from Template 05 - Tornado Chart
You just need to input Low, Base (Medium) and High values of the impact of the variables on your project objective for which you are doing the sensitivity analysis.
And you, will get the Tornado Chart.