Month: August 2022

Two dead after Thursday night lightning strike near White House

Lightning is an electrical discharge and nature’s balancing mechanism for distributing charge throughout the atmosphere.

Thunderstorms become electrified when electrons, which are negatively charged particles, are shaved off one water particle — like a raindrop, snowflake or hailstone — and end up on another, leaving the former with a net positive charge and the latter a bit extra negative. Generally speaking, ice crystals acquire a positive charge, while raindrops take on a negative charge.

That makes the top of a cloud, where temperature are well below freezing, positively charged. Below that is a more expansive “central negative” within the storm. A shallow, broad positive charge sits at the storm’s base like the bottom of a hamburger bun.

Most lightning we see is either intracloud (within the cloud) or takes the form of cloud-to-ground bolts, most commonly originating from the middle negative charge. The greater the electrical field within a cloud, the more “sparky” the storm will be.

Getting an electric spark to jump through thin air is tricky. The ambient electric field has to be great enough to overwhelm the “dielectric breakdown strength” of air.

Think of a dam. It prevents water from flowing beyond it, unless the volume of water behind it reaches a threshold sufficient to burst the dam. Then the stored-up water can break through unimpeded.

For air, that magic number is 3 megavolts (or 3 million volts) per meter for dry air (it will change some in a storm). Charge accumulating on the surface will begin to bleed into thin air in a fine stream of electrons known as a “corona” discharge. That heats the adjacent air, lowering the resistance and making it possible for that spark to begin spreading in jagged increments.

It’s unclear what processes unfold within a cloud, but eventually what’s called a “stepped leader” of electricity races toward the ground, leaping in a branched, fractal pattern.

What I learned from 20 years photographing lightning in DC

“Upward streamers,” or narrow tendrils of electricity, reach skyward from the surface, akin to a group of students raising their hands. Eventually, the downward stepped leader connects with one of the upward streamers to create an unbroken channel of electricity between the cloud and the ground. Current pulses surge through the channel, each causing a burst of light. That’s why lightning appears to flicker.

Surprising facts about lightning

• Lightning isn’t that thick. In fact, it’s only an inch or two across. It just looks wider because of luminosity.
• Lightning is five times hotter than the surface of the sun. Within that narrow lightning channel, the electricity heats the air to nearly 55,000 degrees. That causes a rapid expansion of the air, which produces the atmospheric shock wave we hear as thunder.
• Lightning can be triggered. Researchers at Los Alamos National Laboratory in New Mexico use rockets to trigger lightning, and then employ high-speed cameras and instruments to collect data. It’s also well-established that airplanes, helicopters, tall man-made structures and even wind turbines can spark their own strikes.
• “Upward lightning” is a thing. It’s exactly what it sounds like — lightning that leaps from the ground to the cloud, fanning outward along the cloud’s expansive lower positive charge. In fact, self-initiated upward leaders are common from man-made transmission/broadcast towers, and are an area of ​​emerging research.
• Some lightning is more likely to spark wildfires. Although lightning is extremely hot, it is also brief. That limits its window of opportunity to ignite a wildfire. But instead of current flowing between the sky and ground in a brief series of staccato bursts, some lightning takes the form of a “continuing current” discharge. That means the current flows over longer-duration pulses. Because the current is heating the ground for longer, the odds of a wildfire climb markedly.
• Men are struck roughly four times as often as women. In the United States, men account for 84 percent of lightning fatalities, and women make up the remaining 16 percent.
• Lightning fatalities are trending downward. Because of improved forecasts, education and awareness, lightning fatalities have decreased significantly in recent decades. An average of 43 people died of lightning strikes annually in the United States between 1989 and 2018, but the average dropped to 23 between 2012 and 2022. A record low 11 deaths occurred in 2021.

Tips and facts to know for staying safe when there’s lightning

• Never shelter under a tree. If lightning strikes a tree, the charge can flow through the trunk and laterally strike individuals beneath it, or also spread through the ground. Many lightning tragedies have stemmed from individuals seeking shelter beneath trees. The previous lightning fatality in DC, which took place on May 17, 1991, occurred when a group sheltered beneath a tree during a lacrosse game.
• Leisure activities — especially fishing and boating — are the greatest sources of lightning fatalities. “[F]ishermen and boaters are likely to be out in the open and more vulnerable to a direct lightning strike,” a report from the National Lightning Safety Council from 2020 stated.
• Lightning can strike even in blizzards. Thundersnow is real and it can be dangerous. On Jan. 25, 1990, lightning hit a light pole during a thundersnow storm in Crystal Lake, Ill. The charge traveled through the frozen ground and injured 11 people nearby shoveling snow or pushing stranded motorists.
• Lightning can travel 10 or more miles away from a parent thunderstorm and even strike in clear air far from any rain. These “bolts from the blue” are often more powerful and potent, since they originate from the positively charged top of a thunderstorm. These are among the most dangerous, since they can strike in otherwise tranquil conditions. That’s why experts recommend sheltering at the first sign of thunder, as that’s a sign that you’re close enough to be struck by lightning.
• Ninety percent of lightning-strike victims survive. There are an average of 30 lightning fatalities in the United States every year. The lightning strike near the White House on Thursday brought this year’s fatality count to 11.

Read more about lightning …

‘Gigantic jet’ lightning is a mystery. These researchers are solving it.

Jonathan’s story: After tragic ‘bolt from the blue,’ two simple rules that could save your life

Bolts from the blue: Here’s how lightning can strike when a storm is tens of miles away

Where lightning hit the most in the US in 2021

“Before the 2020 election, I said that if I could know one single fact about the results, I could tell you who was going to win Pennsylvania. Whoever wins Erie County will win Pennsylvania,” Fetterman said in a statement announcing the rally. “Erie County is Pennsylvania’s most important bellwether county. I’ve visited Erie dozens and dozens of times in the past, and I am honored and proud to be returning to the campaign trail here.”

Donald Trump won Erie County in 2016, and Joe Biden captured it in 2020.

Fetterman faces celebrity doctor Mehmet Oz in the November election. Oz has remained active on the campaign trail since prevailing in the Republican primary, although he has faced criticism for reportedly taking trips to Ireland and Palm Beach, Fla.

Despite his absence from the campaign trail, a recent poll showed Fetterman with the advantage. Fetterman held an 11-point lead over Oz, 47 percent to 36 percent, in a Fox News poll released July 28. Three percent backed independent candidate Everett Stern, and 13 percent supported someone else or were undecided.

In an interview late last month with the Pittsburgh Post-Gazette — his first media interview since his stroke — Fetterman said he felt ready to return to the trail.

“I might miss a word every now and then in a conversation, or I might slur two words. Even then, I think that’s infrequent,” Fetterman said. “So I feel like we are ready to run, and that’s the only issues I have. That’s the absolute truth, 100 percent.”

Fetterman’s campaign office announced on May 15, two days before the primary, that he had suffered a stroke “caused by a clot from my heart being in an A-fib rhythm for too long.” The doctors worked to “quickly and completely remove the clot, reversing the stroke, they got my heart under control as well,” Fetterman said in the statement released by his campaign. Doctors attached to a pacemaker with a defibrillator.

He told the Post-Gazette that he has “no physical limits,” walks four to five miles each day in 90-degree heat, understands words properly and hasn’t lost any of his memory. He said he is working with a speech therapist and sometimes struggles with hearing.

The race to fill the seat held by retiring Sen. Patrick J. Toomey (R) is considered one of the most competitive in the country and will help determine majority control of the Senate.

The National Republican Senatorial Committee, the GOP’s campaign arm, has been mocking Fetterman with a count of his days off the trail and an image of him with the words “Have You Seen This Person?”

It sent out another release hours before the Fetterman campaign announcement, saying, “Another Fetterman-Less Friday.”