Input > Define Weather/Wind Types

About This Command

The purpose of this utility is to define weather/wind types associated with different types of fire activity. These definitions can be pieced-together for a series of dates that will automatically generate the required WTR and WND files for a FARSITE simulation.

The idea is to characterize fire weather as it pertains to fire activity. Your options are None, Low, Moderate, High, Extreme, and Other. These will be specific to your location, elevation, the time of year, and perhaps topography. You will then use these "types" to generate a complete stream of weather and wind inputs for a range of calendar dates by just indicating a weather/wind "type" for each day. Of course, you can always edit the Weather (.WTR) and Wind (.WND) Files in any ASCII editor.

For each weather type;

 

  1. Make sure you have selected the proper Weather Type (upper left) and the correct Units (lower left).

  2. Adjust the high temperature, the low humidity and adjust the times at which these maxima and minima occur. These adjustments are above the graph.

  3. Adjust the low temperature, the high humidity and adjust the times at which these occur. These adjustments are below the graph.

  4. Adjust the elevation and rain amount,

  5. select the wind observation interval (ie. 6hr, 4hr, 2hr....) under the Winds -> button

  1. Press the Winds -> button to open the wind definition dialog box. You will notice that a time template will be created with your specified intervals.

  2. Input the speed, direction, and cloud cover for each wind observation time. (Use the TAB key to switch among these input text boxes).

  3. Click the Next button to advance the row of wind observation times. You can also use the vertical slider to the left of the date range.

  4. When finished press OK.

  5. Return to the weather definition dialog box, verify that the wind definitions have been "defined" for that weather type, and select another Weather Type.

 

When Finished with all Weather Types;

Make sure that you save this as a Wind and Weather Definition (.WWD) File. You will need this file for generating the Weather (.WTR) and Wind (.WND) Files using the Input > Generate from Types command.