Tree, Suspiciously Alone During a Thunderstorm

Lightning strike mechanics on isolated tall structures, side-flash arcing, and the 30-30 rule

// IMMEDIATE ACTIONS

Execute these steps in order:

MAX PRIORITY

01
EVACUATE TREE VICINITY IMMEDIATELY

Move away from any solitary tree to a distance of at least twice the tree’s total height to avoid deadly side-flashes.
02
SEEK ENCLOSED BUILDING OR METAL VEHICLE

Head directly to a substantial building or hard-topped vehicle; if in a forest, seek a uniform stand of shorter trees away from edges.
03
CROUCH WITH FEET TOGETHER IF CAUGHT IN OPEN

Squat low on the balls of your feet with heels touching to minimize step potential.

// CRITICAL MISTAKES (DO NOT)

✕ Do not shelter under lone trees, small groves, open picnic pavilions, or tent canopies.
✕ Do not touch tree trunks or lean against bark during a storm.
✕ Do not believe old folklore

WHY: such as "avoid oaks, seek beeches"—lightning strikes any tall species indiscriminately
✕ Do not hold open umbrellas with metal poles near tall trees.

MEMORY HOOK (THE ONE THING TO REMEMBER)

“An isolated tree is a natural lightning rod with explosive side-flashes; keep a distance equal to twice the tree’s height.”

Tall isolated trees are natural electrostatic focal points during electrical storms. Elevated high above surrounding flat terrain, tree canopies launch powerful positive upward streamers toward descending storm leaders.

The Physics of Side-Flash and Steam Explosions

When a multi-kiloampere lightning return stroke attaches to a tree trunk:

Steam Detonation: Tree sap within the cambium layer absorbs extreme resistive energy, instantaneously vaporizing into high-pressure steam that shatters the bark and hurls sharp wood shards in all directions.
Side-Flash Arc: Wood is a relatively poor electrical conductor. The human body—composed of salty electrolyte-rich water—presents a path of far lower electrical impedance. Current readily jumps (arcs) sideways across several meters through the air from the trunk into a human sheltering underneath, entering through the head and exiting into the ground.

Maintain a distance of at least twice the height of any isolated tree or mast.

EMERGENCY DISPATCH NUMBERS