**Step 1: **Determine Reference Fuel Moisture (RFM)

Day Time Hours 0800 – 1959 (Table A)

Night Time Hours 2000 – 0759 (Table B)

- Dry bulb Temperature is determined for the time period in question either by measurement or forecast.
- Using the intersection of dry bulb temperature (F) and Relative Humidity (%) determine reference Fuel Moisture (RFM) in percent.

**Step 2:** Using the Dead Fuel Moisture Content Corrections, match the table having Spring/Fall months (Table C), summer months (Table B) or Winter months (Table D) with the appropriate month.

- Determine if your Fine Dead Fuels are shaded (
__>__50% shading of surface fuels) or exposed (<50 shading of surface fuels). Shading can be due to cloud cover and/or canopy cover. - Determine the aspect of the point (area) for which you are calculating Probability of Ignition (PI).
- Determine the slope: (0-30%) or (>30%).
- Calculate the Dead Fuel Moisture Content Correction for each aspect, slope, appropriate time of day, and the elevation differences between the location of the projection point and the RH/Temp site location

- A – 1000 feet – 2000 feet above site
- L – 1000” of site location
- B – 1000 feet to 2000 feet below site

**Step 3:** Determine Fine Dead Fuel Moisture by adding the Reference Fuel Moisture (step 1) with the Fuel Moisture Correction (step 2).

**Step 4:** To determine Probability of Ignition:

- Use the Fine Dead Fuel Moisture (Step 4), shading present (Step 2a), and the dry bulb temperature (step 1b)
- Using the Probability of Ignition Table to determine your PI.

**Step 5:** Nighttime Calculations

- Use Table E for Reference Fuel Moisture
- Use Table F for Dead Fuel Moisture Content Corrections
- Use Probability of Ignition Table as in Step 4.