Wednesday, April 21, 2021

The Arctic has seen an increase in lightning

by Randy Mann
| April 5, 2021 1:06 AM

It may be a month with near-to-below normal precipitation totals across North Idaho and the rest of the Inland Empire. There is a chance of some showers this week, but moisture totals are expected to be on the light side. However, there is another system that has a better chance of producing some rain later this weekend and toward the middle of the month. In terms of snowfall, there is still a chance we’ll see a few flakes around the middle of April, but mainly over the mountains.

The normal precipitation for this month is 1.77 inches. Last year, Cliff measured 0.99 inches in April. Our March of 2021 total was only 1.05 inches of rain and melted snow compared to the normal of 1.94 inches. The first three weeks of March were the driest and most snowless in history. We still see a pattern with periods of extended dry and only occasional wet weather this spring season.

There continues to be a huge drought pattern in the western U.S. that has expanded into the central portions of the country. Not much moisture is expected in California this month as its rainy season is coming to an end, so, unfortunately, it looks like another rough fire season ahead. North Idaho seems to be on the edge of this weather pattern, but we do see the big high-pressure ridge weakening from time to time over the next three months to occasionally allow some moisture into the region.

We’re also coming into the time of year when we often see more thunderstorm activity. Last year was below normal for instances of lightning in our region, and 2021 should be similar. However, in the Arctic regions where lightning strikes are considered to be “historically rare,” a new study in Geophysical Research Letters says that these flashes in regions above the 65-degree line of north latitude have tripled from 2010 to 2020. According to the study, the actual number of lightning strikes went from about 18,000 in 2010 to over 150,000 in 2020.

Data was used from the World Wide Lightning Location Network (WWLLN), which maps lightning strikes across the globe. The increase in activity in the Arctic is likely due to the increase in temperatures, especially during the summer months. It’s also possible that with better technology, instruments are more sensitive to these events resulting in slightly higher readings.

Although a lightning strike only lasts for mere microseconds, a typical bolt contains approximately 1 billion volts. The average bolt is estimated to power a 100-watt lightbulb for 3 months. The speed of a lightning flash is at the speed of light, which is 670 million miles per hour. However, a lightning strike to the surface travels close to 270,000 miles per hour.

Each day there are approximately 3 to 8 million flashes across the globe. They can seem quite large when viewing from a distance, but the width of a typical bolt is about an inch. The length can stretch for up to 2-10 miles. The duration of a lightning flash is about one-fifth of a second. The typical bolt of lightning is about 40,000 to 50,000 degrees and is about four to five times hotter than the surface of the sun.

Damage costs from lightning are estimated at $4-5 billion each year in the U.S. And, there are more than 10,000 forest fires caused by lightning. In the Inland Empire, many of our large fires in the summer and early fall seasons have been caused by dry thunderstorms that were generated from numerous lightning strikes.

Lightning is the most dangerous and frequently encountered weather hazard that people experience. It is the No. 1 cause of storm-related deaths and Americans are twice as likely to die from this phenomenon rather than from a hurricane, tornado or flood. Twenty percent of all lightning victims die from the strike while seventy percent of survivors will suffer serious long-term effects. Many survivors of lightning strikes report immediately before being struck that their hair was standing on end and they also had a metallic taste in their mouth.

The odds of being struck by lightning is about 1 in 10,000. However, a gentleman by the name of Roy Sullivan was hit by lightning on seven different occasions and survived all of them.

And, with lightning comes thunder. We hear the thunder as a superheated lightning bolt of up to 50,000 degrees that produces a rapid expansion of the air. The rapid compression of the air often creates a sonic shock wave, similar to a sonic boom. Many of those thunderous booms can range from a sharp, loud crack to a long, low rumble.

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