A rare dazzling light show for the Inland Northwest

With crystal clear night weather, residents of the Inland Northwest were treated to a dazzling display of lights. This was caused by a rare, high-intensity geomagnetic storm that originated on the sun last Wednesday. Many people around the Coeur d’Alene and Spokane region posted spectacular photos of these “northern lights” that highlighted the green, purple and other colors across the night sky.

It appears that any major damage from this instance of high solar energy was avoided. However, there were reports of some irregularities in power grids and high-frequency communications, as well as GPS systems across the northern regions of the U.S. and Europe. The last time that satellites were exposed to this type of “extreme” event was in October 2003. This event was first rated a 4-out-of-5 in terms of severity when it began. Last Thursday evening, scientists upgraded the intensity to a 5, the highest level.

Despite this rare event of extreme solar intensity, flares and other related outbursts from the sun are more common than we may think. The most powerful types of solar flares are rated as “X-class flares.” In 2023, there were 12 instances, which was the most than the previous five years combined.

During a period of high solar activity, these auroras will literally “dance” around both of the Earth’s poles and are seen mostly in high latitudes. In our hemisphere, they are known as the “northern lights” or “aurora borealis.” In the Southern Hemisphere, where the same light shows were seen over the weekend, they are known as the “southern lights" or “aurora australis.”

These flares are often generated from sunspots, which are storms on the sun. During the height of a maxima cycle, its magnetic poles on the sun will usually flip as the North Pole becomes the South Pole and vice-versa. The last solar cycle, which was No. 24, began in late 2008 and ended in late 2019. That one was the weakest in recorded history and we’re now in Solar Cycle 25, obviously a much more active one. This is the 25th cycle since 1755 when extensive observations of the sun began.

Within the last year, the number of sunspots has been the highest since 2002. For much of 2023, the average number of sunspots reported per day on the sun has been close to 130. Since the beginning of the year, there has been an average of 125 sunspots observed each day. However, since the middle of April, there has been an average of about 185 sunspots reported daily. The highest number was 283 sunspots reported April 22, 23 and 25. Historically, the average number of sunspots is about 175 during each cycle when the sun is in its “maxima” phase. During the “minima” in the 2010s, the average number of sunspots was 81, but there were long stretches with no sunspots reported.

In addition to sunspots, the chances of CMEs are higher during this “maxima” cycle. A coronal mass ejection (CME) is a large release of plasma and accompanying magnetic field from the sun’s corona, which is the outer layer of its atmosphere. They will often follow solar flares and be released into the solar wind. They will travel away from the sun and can reach our planet as fast as 15-18 hours, but most will take up to several days. Since last Wednesday, the Space Weather Prediction Center observed an unusual cluster of sunspots on the sun that were approximately 17 times the diameter of our planet.

Fortunately, the magnetic field around our planet protects us from the harmful effects of the sun. Scientists say that it’s generated by the Earth’s liquid iron core. The core’s continuous cooling and crystallization lead to powerful electrical currents that generate our magnetic field into space. When charged particles from the sun interact with our magnetic field, they will give off light.

One of the strongest solar storms in recent history is the infamous Carrington Event in 1859 when a super-strong solar flare hit the Earth. During this period, auroras were seen in areas as far south as Cuba and Hawaii.

Scientists say that even the largest solar flare would not likely impact lifeforms on Earth. However, satellites, power grids and other forms of technology would be highly vulnerable, especially with another Carrington Event. If this were to happen again, damage from the flares could climb into the trillions of dollars.

There’s a decent chance that we could see more light shows in our region into 2025. This solar cycle is not expected to peak until at least late 2024 or 2025. There are many astronomical websites, including space.com, that will provide the probabilities of more northern light shows several days in advance.

In terms of our local weather, the last few days were perfect for viewing the incredible light show as skies were clear and highs managed to climb to near 80 degrees in most areas. Temperatures will be cooler this week along with the possibility of some scattered rain shower activity. There is a better chance of rain across the Inland Northwest as we get close to the full moon lunar cycle that begins May 23.

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Contact Randy Mann at randy@longrangeweather.com.