1. Moving Area Blocks How do moving area blocks work with Preset Polygons
Alert Message Polygons
Subject event Polygons

2. Preset polygons translate to geocodes in a CAP file that then make heavy use of lookup tables (common in non-GIS CAP based systems)

3. Preset polygons change to reflect the new time period by adding or deleting new polygons to the list of affected polygons

4. Alert message polygons define the area to be alerted (used when mapping to broadcast assets within the affected area)

5. Alert message polygons change to reflect the new area to be alerted (used when mapping to broadcast assets within the affected area)

6. Subject event polygons define the threat zone of the hazard as it exists at T+0 and the motion vector provides advanced systems with the information needed to progress the polygon through time

7. Subject event polygons define the threat zone of the hazard as it exists at T+0 and the motion vector provides advanced systems with the information needed to progress the polygon through time

8. Questions?
Originators and Distributors will make assumptions realizing later several approaches exist
Preset polygons deprecated?
Alert message/Subject event polygons result in a distribution asset that is discontinued by not mapping as an asset in the polygon rather than an expires or cancel
Alert message/subject event polygons result in a message possibly starting, continuing and ending for a specific location without an Alert or Cancel involved?
Subject event polygons may require more frequent updates
Will likely require the use of an PTF (Protocol Transfer Function)