In practicality this spike was brief and using the 15 minute threshold period (current is the average of the last 15 minutes) the value for calculating change would be 136 and the resulting change would be 36% so a Major event. The threshold period is dampening the spikes to remove brief changes and allow you to see changes which last longer.
Installing the Baseline Tool
Copy the file to the server and do the following, upgrading will be the same process.
tar xvf Baseline-X.Y.tgz cd Baseline/ sudo ./install_baseline.sh
Working with the Dynamic Baseline and Thresholding Tool