Wind Vectors are a unique type of FlamMap vector file. A Wind Vector is a combination of the Wind Direction and Speed grids displayed as an arrow.
The display of Wind Vectors can be modified in the "Wind Vectors Legend" dialog box.
Wind Vectors can be created in several ways,
NOTE: Wind Vector shapefiles cannot be used for fire behavior calculations in FlamMap, only Wind Grids or the WindNinja Option can be used to calculate fire behavior outputs.
The Wind Ninja Options button is activated when the Generate Gridded Wind radio button is selected on the Inputs tab of the "Run:" dialog box. More information on WindNinja can be found at the Wind Ninja website.
Clicking the Wind Ninja Options button opens the "Wind Ninja Options" dialog box.
The basic Wind Ninja Option is to simply select a resolution for the Wind Grids/Vectors and click the OK button. Your resolution should be larger than the landscape resolution or Resolution of Calculations setting (Minimum Travel Time or Treatment Optimization Model tabs). Typically 2x or 3x the landscape resolution will give good results. However if your computer memory is limited you should adjust the Resolution: to keep the Number of Wind Ninja cells: under 200,000.
For runs not using Diurnal Simulation a Calculation Date/Time is not required. Wind Ninja simply calculates the Wind Grids/Vectors given the landscape terrain and the Wind Speed/Direction entered in the spin boxes on the Inputs tab.
A simple model has been included in Wind Ninja to simulate diurnal slope winds. It is designed to compute small scale slope winds, but not larger scale valley winds. The slope winds will have some effect of producing valley winds, but it will be slight. Also, the model will not simulate other buoyancy driven flows such as sea or land breezes.
For a Wind Ninja Diurnal Simulation select the Use Diurnal Simulation check box and use one of the following options to fill in the Air Temp and Cloud Cover spin boxes.
Remember Wind Ninja calculates the Wind Grids/Vectors given the landscape terrain and the Wind Speed/Direction entered in the spin boxes on the Inputs tab. During the wind computation, these winds will be combined with the diurnal winds to produce the final wind field. Output of simulations done with light domain average winds (say 1-5 mph) will show significant effect of the diurnal winds. Strong domain average wind cases will not show much diurnal effect because they are overpowered.
WARNING: When manually entering Diurnal Settings be careful that the fuel moistures are calculated at the same simulation time as the Diurnal Simulation winds! i.e. using mid-afternoon fuel moistures with nighttime diurnal simulation could result in unrealistic or bizarre results.
Three items make up the gridded wind outputs for a FlamMap run.
The display
properties of 
♦Wind Vectors can be modified in the same
way as Spread and Max Spot Vectors. The ♦Wind
Speed and ♦Wind
Direction display can be changed
like any other grid.
A Farsite simulation can utilize gridded winds to adjust the weather stream winds to the terrain for each timestep. The Wind Ninja Options button is activated when the Generate Gridded Wind from Weather Inputs radio button is selected on the Weather Inputs tab of the "Farsite Run:" dialog box.
Clicking the Wind Ninja Options button opens the "Farsite Wind Ninja Options" dialog.
The Farsite Wind Ninja resolution should be larger than the simulation's Perimeter Resolution and Distance Resolution settings. (Farsite Model Settings tab). Typically 2x or 3x those resolutions will give good results.
It's important to realize that Farsite will create a separate Wind Ninja run and store the results in memory for each weather record within the burn periods. This can result in dozens of Wind Ninja runs for a single Farsite simulation. This will often cause your Farsite simulation a long time to complete. If you are in a hurry or are using a computer with limited memory you should adjust the Resolution: to keep the Number of Wind Ninja cells: under 200,000.
A simple model has been included in Wind Ninja to simulate diurnal slope winds. It is designed to compute small scale slope winds, but not larger scale valley winds. The slope winds will have some effect of producing valley winds, but it will be slight. Also, the model will not simulate other buoyancy driven flows such as sea or land breezes.
Remember Wind Ninja calculates the Wind Grids/Vectors given the landscape terrain and the Wind Speed/Direction from the loaded Weather Stream (.WXS) file. During the wind computation, these winds will be combined with the diurnal winds to produce the final wind field. Output of simulations done with light domain average winds (say 1-5 mph) will show significant effect of the diurnal winds. Strong domain average wind cases will not show much diurnal effect because they are overpowered.
To add Wind Ninja Diurnal Winds to a Farsite simulation simply select the Use Diurnal Simulation check box.
The "Farsite Progress..." dialog shows the progress of the Wind Ninja portion of the simulation, all Wind Ninja runs are completed before Farsite begins calculating fire behavior.
More information concerning WindNinja performance can be found in the Computational Performance topic.
Wind vector outputs for a Farsite run are a compilation of all the different wind grids used in the run. Only the individual wind cells used for each timestep perimeter are shown as vectors. So wind vectors in different timesteps are from different landscape wide wind grids.
The display properties of Farsite Wind Vectors can be modified in the same way as Spread and Max Spot Vectors.
The complete set of wind grids can be saved in GeoTIFF format and used in other applications like a GIS.