Dynamic Alerts based on DAX measure

Hi All -  I'd like to set up "dynamic" alerts with a few of my dashboards that will trigger based on a dynamic threshold based on standard deviations from the mean. However, there appears to be a limitation with the current alerting capability in that it only allows the alert to be triggered on a static threshold. In my use case, the threshold will change (usually significantly) based on the most recent hourly refresh, so a static threshold would not suffice. Here's a screenshot of the alert interface I'm referring to. The '68.1' figure should instead be the "lower control limit" measure which already has been created in the underlying BI desktop file. Any ideas would be much appreciated!