If you no longer want to receive alerts notification for a monitored condition set in an custom alert, all you need to do is remove the alert from your account.
System Alerts monitor your AcuRite devices, which are the heart of the My AcuRite monitoring solution, therefore they cannot be removed. If you do not want to receive notification for a System Alert, you can set the notifications to be silenced.
From the tab / navigation bar, select (Settings menu).
Select Manage Alerts.
Select the name of the alert to be removed.
From the upper right corner, select the icon.
Select Yes, Delete.
The Alert is removed from your account and any notifications generated by the Alert are also removed from your Alerts menu.