Potential Rate Of Spread (PROS) Risk Assessment Process

A “Potential Rate of Spread Chart” (PROS) has been developed in an effort to assist firefighters in better understanding the significance of the dynamic environmental conditions they are working in. PROS is designed to help firefighters identify when they are approaching or working in environmental conditions where there is little room for error, and minutes and seconds may be the difference between life and death when things go wrong.   To use the PROS chart, first record weather observations. This should be done at least hourly.  Locate the temperature on the left side of the chart, and the relative humidity on the right side of the chart.  Then draw a line between the two.  Next, determine the slope percent at your location, and the current average mid flame wind speed.  Then draw a line between the two points. The point where the two lines intersect is the Relative PROS Value.  Detailed instructions for use are included in the download file!

Potential Rate Of Spread from Probability of Ignition (PROS-PI) Risk Assessment Process

The PROS-PI chart was developed for more experienced firefighters and provides a more precise assessment of the risk associated with the environmental conditions found on the fireline.  It does so by utilizing fine fuel moisture and Probability of Ignition values determined for a specific location.  Detailed instructions for use are included in the download file!

Download PROS & PROS-PI Files 1/2/2008

19,929 kb self-extracting zip file

To download click on the Download link and save the file to your computer.  Double click the filename on your computer to extract files.  The default location for the files will be C:\PROS.  You can select another location if you prefer.  Thank-you for your interest in PROS!