Grapher Article Firing Up Grapher for Windows A number of physical factors can change the behavior of a brush fire or forest fire, and Grapher can help track and analyze the ways a fire changes. Some of the factors influencing a fire are slope, slope aspect, weather, time of day, fuel temperature, fuel type, and topography. These factors can affect the fire's rate of spread, spotting, and flame lengths, and can cause erratic fire behavior. Slope affects fire behavior because fire can preheat the fuel in front of it and create a chimney effect, making the fire burn faster uphill.
Unstable atmosphere caused by weather can trigger erratic fire behavior.
For example, wind can either fan a fire or be so strong that it snuffs out the fire. A large, complex fire can even create its own weather, further influencing fire behavior. The temperature and type of fuel also affect the fire. As you can see from Figure 1, fuel temperature increases through the middle of the day. Fuel type determines whether the fire carries horizontally or vertically or both.