Setting the duration is required for every FARSITE simulation. This command brings up the "Simulation Duration" dialog box where you set the start and stop times of a simulation. Weather (.WTR) and Wind (.WND) Files must be loaded before the duration can be set.
The option to Reset Duration at Restart is found in the "Simulation Options" dialog box, (Simulate > Options menu command).
Specifying a fuel conditioning period is an option to adjust fuel moistures prior to the start of a simulation. When the Use Conditioning Period for Fuel Moistures check box is selected, FARSITE starts with values in the Initial Fuel Moisture (.FMS) File and calculates fuel moistures across the landscape based on elevation, aspect, slope, and shading before the Starting Time of the simulation.
If the Use Conditioning Period for Fuel Moistures check box is cleared, FARSITE begins the simulation with every point on the landscape using fuel moistures from the Initial Fuel Moistures (.FMS) File. Fuel moistures are then adjusted for topography and shading during the simulation, eventually equilibrating to the local environment.
Not specifying a fuel conditioning period may over or under predict fire behavior depending on the location used for the Initial Fuel Moistures. The effect of a conditioning period on long simulations (a week or longer) or fuel models with only 1 hr. fuels is very small. Conversely, shorter simulations with longer timelag fuels can show different results with and without a conditioning period. If the results of the Post-Frontal Combustion model are important, then perhaps longer Conditioning Periods to equilibrate 1000 hr. fuels and duff might be appropriate.
Weather and wind streams are required in the Weather (.WTR) and Wind (.WND) Files for the conditioning period. Also weather data is needed for a minimum of one day before you start the conditioning period.
Selecting the Use Conditioning Period for Fuel Moistures check box will display the earliest day available in the Weather (.WTR) File to begin the conditioning period. Conditioning periods are for whole days only. Conditioning begins at 0000 hrs. on the day specified, the dialog box will not accept hours and minutes input.
Starting and Ending times are simply set with the appropriate spin boxes. If zero is displayed in any of the text boxes, clicking the up or down arrows will insert the earliest available value. Minutes are optional.
The simulation ending time can be changed while the simulation is suspended. Simply bring up the "Simulation Duration" dialog box and lengthen or shorten the simulation. This can be handy for "testing" long simulations before committing to hours of computational time before realizing some options or adjustments were not set correctly.