Why Trees Blow Up When Hit By Lightning And Where To Be If It Strikes Near You

Jun 26, 2015

If you live in the Pacific Northwest, a scary lightning strike isn’t very likely.

But there was one recently in Seattle’s Arboretum that could be a case study in a text book.

“The lightning bolt went right down the moist center of the tree, blew the tree out and so it just spread apart,” Mass said.

He says in this case, the lightning hit just right and heated up the moisture at the core of the tree, causing steam to form and blast it into pieces.

“Pieces of that tree were sent off as projectiles, hundreds of feet away,” and embedded themselves deeply into the ground because of the force of the blow.

“It was amazingly dangerous,” Mass said.

“And there’s been explosive trees around here before; this is not the first incident. But it’s probably the most dramatic I’ve ever seen,” he said.

He says he’s never seen anything like it, at least not in nature.

“It looked like one of those onions you get at Safeco Field,” he said.

In this week’s episode Mass explains why lightning strikes are relatively rare here, why the recent one near the Arboretum visitor center was so forceful and how to position yourself on the off chance that you do get caught in a lightning strike.

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The weekly KPLU feature "Weather with Cliff Mass" airs every Friday at 9 a.m. immediately following BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KPLU Environment Reporter Bellamy Pailthorp. Cliff Mass is a University of Washington Professor of Atmospheric Sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to a podcast of “Weather with Cliff Mass” shows.