EC2 Auto Scaling now publishes predictive scaling policy’s forecasts as a CloudWatch metric, enabling you to analyze, monitor, and set alarms on the accuracy of predictive scaling. Predictive Scaling is a scaling policy that proactively increases the capacity of your Auto Scaling group ahead of predicted demand, improving the availability of your application while reducing the need to stay overprovisioned that otherwise would have increased your EC2 bill. As predictive scaling only increases the capacity for your Auto Scaling groups, applying it to your current scaling configurations strictly enhances your application availability. However, an inaccurate prediction can potentially increase your cost. Now, you can use the extensive list of CloudWatch features to measure accuracy of predictions, view forecasts using the familiar CloudWatch graphs, and also set automatic alarms and notifications when predictions are above your desired levels.
Source:: Amazon AWS