What is already known:
What this study adds:
Sergeant JP Finley used a 2 x 2 contingency table to forecast tornado occurrences. This table allowed a user to obtain probability of detection (POD), false alarm ratio (FAR), critical success index (CSI), Success ratio (SR), and the Bias. These metrics help evaluate help provide the value and quality of a forecast. Recent studies of national weather service tornado warning performance for the Central, Eastern, and Sothern regions from 1986 - 2011. This study found a major decrease in false alarm ratio (FAR), probability of detection (POD) starting 2012 for the Central region, while the Southern and Eastern region displayed no change in false alarm ratio (FAR) or probability of detection (POD) until the following year. A warning forecaster has lots of information to consider before issuing a warning. They have radar, spotter reports, environmental conditions, historical data sets, etc. These elements all play a role in the weight of evidence required to issue a warning or not. If there is enough weight of evidence to issue a warning that goes above the threshold set in place most times the forecaster will issue a warning. This of the paper will be the regional analysis of regional performance focusing specifically on the time-period around the change in 2012.