Some facts, reactions to thunder, lightning

Kirk Ericson | May 18, 20230

You might not know this about thunder:

“Thunder is created when lightning passes through the air,” according to the National Weather Service. “The lightning discharge heats the air rapidly and causes it to expand. The temperature of the air in the lightning channel may reach as high as 50,000 degrees Fahrenheit, five times hotter than the surface of the sun. Immediately after the flash, the air cools and contracts quickly. This rapid expansion and contraction create the sound wave that we hear as thunder.”

The unusually intense lightning storm that marched through the region late Monday night and early Tuesday morning was the talk of the neighborhood coffee shop several hours later. A barista said one of the strikes knocked out the transformer in her area. “It was so loud,” she said, “it literally scared me to death.”

“The birds were extra loud this morning,” one customer said. “It smelled and felt like a tropical climate.”

A few complained of not getting enough sleep — it was that kind of loud. It was the kind of loud that breaks things. It was the kind of loud that made our cat follow me around the next morning like he was a duckling reunited with mom. Mr. Cool Cat was now Mr. Scaredy Cat.

I live barely east of Interstate 5 in Thurston County and, according to the National Weather Service, the most intense strikes of the storm tracked from eastern Lewis County north through eastern Thurston County, Pierce County and into King County, south of Interstate 90.

I spent some of that night driving our youngest son back to college in Seattle. We left at 9:15 p.m. and could see lightning flashes in every degree, except to the southwest where Kitsap and Mason counties lie. When I got home around midnight, the noise and light amped up, before petering out around 1:30 a.m.

My son and I learned we don’t know much about lightning, so I called Reid Wolcott, who’s the warning coordination meteorologist in the Seattle office for the National Weather Service.

The unusually high temperatures during the previous four days contributed to the creation of the storm, Wolcott explained. The high heat, “combined with the increasing moisture, led to a considerable amount of instability,” he said. “And instability is one of those critical ingredients you need in order for thunderstorms to develop. You also need ample moisture and a source of lift. Yesterday, we had that combination of that instability, moisture and lift.”

The electrical storm covered the Northwest, from Montana through Idaho and into northern Oregon and up into Washington. The western half of Washington, excluding the Cascade crest, had about 1,300 lightning strikes, Wolcott said.

Wolcott explained the three types of lightning.

“You have the in-cloud variety,” he said. “That’s when lightning jumps from one cloud to another or across a single storm system. That’s the most common type. It never reaches the ground. Then you have a negative cloud-to-ground strike. Those are the most common cloud-to-ground type strikes. Then we have what are called positive lightning strikes. And those are on the order of about 10 times the power of a negative lighting strike. If you’re near one of those when they hit, they carry more energy with them, so they can be louder. About 5% of lightning strikes are positive strikes.”

Positive lightning strikes originate in the top reaches of a cloud, where it’s the coldest, Wolcott explained. The top portions of clouds, “typically have a lot more ice and the potential for interaction, which causes the electricity to build up within a cloud. The cloud essentially acts as a big battery. The more ice you have, the more charge you can generate and the more lightning you can generate from that.

“When the ice particles crash into each other, it’s like rubbing your feet on carpet,” Wolcott said. “You get a little static charge, right? When ice bangs together in a cloud it causes an electrical charge.”