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Setting up FSPro Winds
The FSPro simulation is greatly influenced by winds, so Fire Behavior Specialists must modify FSPro winds in order to generate good quality analysis data.
For each analysis, FSPro generates a time-series analysis based on historical wind data from the selected Remote Automated Weather Station (RAWS). These historical winds are used for all days outside of any forecast winds. For instance, a 14-day analysis may use 4 days of forecast winds and 10 days from the time series.
As you modify FSPro winds:
- Select a RAWS that is representative of the fire area. Consider the wind speeds and directions that influence observed and expected fire behavior. Ask local fire staff or meteorologists which station best represents winds at the fire location. In locations with terrain it is important to locate a station that is similarly aligned with the topography. Since weather (relative humidity, temperature etc.) are not incorporated into this RAWS selection, the best station for winds may not, necessarily, be the closest on to the incident.
- Ensure that the selected RAWS has sufficient historical data to support the time-series analysis. Some RAWS stations may only have a few years of data available (unlike the ERC station selection 10 years of data is not required). Generally, the more years of data that you can capture for winds the better. When making your RAWS selection, be aware of that there could be gaps in the data. You can talk with a local expert and/or download winds to look for these gaps.
- Test the year filter to determine the optimal timeframe for the historical winds data. The year filter can be set for as long as the station has data. Try different time frames to detect a difference in the wind bins.
- Review the Wind Rose. Winds are binned for computational efficiency. The values in the wind bins are the same as the graphical wind rose. The values in each bin display as percents.
- Select a Winds Type of “both” and Generate Wind Matrix when modeling "very high" to "extreme" conditions. Doing so increases wind speeds and includes a greater representation (higher percentages) in the higher wind-speed categories. Gusts only are also an option but use caution, selecting this option may cause the model to overpredict fire probabilities.
To set up FSPro winds:
- From the Analysis List page, select the FSPro analysis for which you want to modify the winds.
- Click View Information. The General FSPro Information page appears.
- From the left menu, select Winds. The FSPro Winds page appears.
- Verify that the selected RAWS is the one most appropriate for the analysis.
- Set the time filter, start date, end date, start hour, and end hour.
- The month filter is typically set to one month before and after the ignition, which is the default.
- The hour filter should only include the time when the fire advances (the burning period.)
- Select the Winds Type. For Weighted Winds, a calm weight and calm threshold is automatically calculated once the wind matrix is generated. You don't need to modify the Calm Weight or Calm Threshold unless you edit the matrix.
- Click Generate Wind Matrix. After a few seconds, the generated matrix appears. The bins display a percentage, expressed as whole numbers with two decimal places (e.g., 1.54% appears as 1.54).
- Click Wind Rose. A graphical represenation of the winds appears. You can use the rose to answer the following questions:
- Is the wind direction logical?
- Are the wind speeds realistic based on current conditions and historical observations?
- Click Save Winds.
- Document your decisions about winds in the FSPro analysis notes.
You can now modify the wind matrix to fit the analysis parameters you want to include. (See Editing the Wind Matrix for more information.)
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Last updated on 11/21/2017 3:02:58 PM.
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