FSPro (Fire Spread Probability) is a fire modeling system that calculates the probability of fire spread from a fire perimeter or ignition point for a specified time period. Combining landscape data layers (crown base height, crown bulk density, etc.), current weather forecasts, historical weather scenarios, fuel moisture classifications, fire history, and wind speed and direction, FSPro can produce fire probability projections for 7 to 10 days and perhaps as far out as 30 days. The model is designed for situations when managers don't have a high level of confidence in weather projections, or for periods when long-term weather projections aren't available. The system starts with current weather forecasts and integrates historical data from a nearby weather station with similar topography to create many different weather scenarios. The fire spread is simulated using each of the potential weather scenarios. This document is intended to be a user?s guide for FSPro analysis in Alaska. It is not intended to be a cookbook of ingredients to be added to FSPro but rather, a starting point for analysis. This summary includes working guidelines and calibration techniques used in Alaska from 2008 through 2011 along with information gathered from the Help Menu in WFDSS, materials from S-495, documents written by analysts for Alaska, and published papers.