Welcome to the AngelSense Support Center

"Early Warning Mode" Overview

The AngelSense system has sophisticated algorithms to filter out false GPS readings given by GPS. GPS is limited indoors, regardless of AngelSense, and we use these algorithms to make the best of GPS technology to ensure accurate readings.  
Early Warning Mode basically relaxes the system when filtering out these readings so that you get faster notifications of exits. This is what the message refers to when enabling the Early Warning Mode about "a higher rate of false alerts". We have this mode to enable parents to have faster alerts because we know just how quickly a child can elope. Most parents prefer these occasional false alerts in order to receive faster alerts and then just determine if they are true or not.
If you receive many false alerts, enlarging the radius of the location may help. If you would prefer not to receive these occasional false alerts you can always choose to disable the Early Warning Mode. 

Related Articles:

Enabling "Early Warning Mode" for a place
Notifications delay
Notification types
Configuring arrival/departure notifications
Configuring reminder notifications
Handling False Notifications
Location via text
Runner Mode Overview
Transits Overview
Timeline Overview
Preserving Battery Life