Watch Out Situation #4:  Unfamiliar with weather and local factors influencing fire behavior.

Thunderstorms cause significant hazards for wildland firefighters, including downbursts. Downbursts can cause extreme fire behavior and lightning. When thunderstorm development is likely, lookouts should be aware of the signs.

Approaching thunderstorms may be noted by a sudden reverse in wind direction, a noticeable rise in wind speed, and a sharp drop in temperature. Rain, hail, and lightning occur only in the mature stage of a thunderstorm.

Spot weather forecasts should be requested or submitted online for those fires that have potential for extreme fire behavior, exceed initial attack, or are located in areas where Red Flag Warnings have been issued.

The 10 Standard Firefighting Orders and the 18 Watch Out Situations, as referenced in the NWCG Incident Response Pocket Guide (IRPG), PMS 461, provide wildland firefighters with a set of consistent best practices and a series of scenarios to be mindful of when responding to a wildland fire.

The National Fire Danger Rating System (NFDRS) PocketCard is a tool for field personnel to locally track fire potential throughout the season. It is based on historical weather and fire occurrence for a localized area. The PocketCard displays a general assessment of the fire potential and identifies combinations of local weather and fuel conditions that might contribute to severe fire behavior.

Spot fires occur when embers land on the unburned side of a fireline. This Watch Out depicts an engine crew attempting to contain several spot fires which are increasing in size while the main fire is also growing.

Fire managers make decisions throughout the day on how to suppress fires and best use resources while protecting life and property. This Standard Firefighting Order depicts a firefighter observing increased fire behavior during a time of day when temperatures are high and relative humidity is low.

Changes in fire behavior have always been present in cases of shelter deployment. Firefighters maintain a heightened awareness of daily fluctuations in live and dead fuel moistures, along with current and predicted weather conditions. Other inputs like fuel type and topography add to the picture. Firefighters must cultivate a healthy respect for these factors. When fuel moistures, fuel type, weather conditions, and topography align, extreme fire behavior is likely.

Use the NWCG Incident Response Pocket Guide (IRPG), PMS 461, to review and discuss the five major common denominators of fire behavior on fatal and near-fatal fires. These common denominators have been identified through studies of tragedy fires. It is important for firefighters to readily recognize them to prevent future tragedies.