Collision areas are marked with the number of seconds since the issue time to the time of that collision. The collision information is placed on a grid in a given storm's final extrapolated position. Other Information Other information is calculated in bdryStormCol that deals with boundary storm characteristics. For each storm, the boundary that is closest to the storm, within some maximum allowable distance, is identified, if it exists. The distance from the leading edge of the storm to that boundary is calculated.
Vector addition is used to calculate the relative speed and direction of the boundary to the storm.