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.
Situation Awareness: Sound waves move at different rates based on atmospheric conditions. Take the storm precautions below as soon as you hear thunder, not when the storm is upon you. Do not resume work in exposed areas until 30 minutes after storm activity has passed.
- Take shelter in a vehicle or building if possible.
- If outdoors, find a low spot away from tall trees, wire fences, utility lines and other elevated conductive objects. Make sure the place you pick is not subject to flooding.
- If in the woods, move to an area with shorter trees.
- If only isolated trees are nearby, keep your distance twice the tree height.
- If in open country, crouch low, with feet together, minimizing contact with the ground. You can use a pack to sit on, but never lie on the ground.
- If you feel your skin tingle or your hair stand on end, immediately crouch low to the ground. Make yourself the smallest possible target and minimize your contact with the ground.
- Don’t group together.
- Don’t stay on ridge tops, in wide open areas, or near ledges or rock outcroppings.
- Don’t operate landline telephones, machinery, or electric motors.
- Don’t handle metal hand tools or flammable materials in open containers.
Incident Management Situation Report (IMSR)
10 Standard Firefighting Orders, PMS 110
18 Watch Out Situations, PMS 118
10 & 18 Poster, PMS 110-18
NWCG Incident Response Pocket Guide (IRPG), PMS 461
RT-130, Wildland Fire Safety Training Annual Refresher (WFSTAR)
Interagency Standards for Fire and Fire Aviation Operations (Red Book)
Wildland Fire Lessons Learned Center