If you glance across Auke Nu Cove from the parking lot of the Juneau ferry terminal, you’ll notice a bizarre area of fallen treesapproximately a dozenwhich are scattered all over.
Jesse Escamilla drives by on his commute to work in the evening every day. He’s familiar with some fallen trees around the area of his Lena Point home, but the trees that fell on Auke Nu Cove seemed mysterious and distinct.
“It seemed odd, like it was not a part of the landscape,” he said. “I remember it appearing as if an excavating machine went in and deliberately flattened that entire area.”
Escamilla was born in Texas The pattern was reminiscent of the marks that tornadoes leave. This became part of one his main theories.
“Option one is Godzilla while option two could be a tornado” he stated. “Both of them are possible and, based on my experience, are viable.”
National Weather Service meteorologist Rick Fritsch says the fan of fallen trees may be evidence for one of the strangest wind-related phenomena.
“To me, it is a lot like a microburst” Fristch said.
The Southeast Alaska Land Trust manages the wetlands that are surrounded by trees. The conservation staff of the land trust said that the trees fell during the midst of a severe wind storm which occurred in the month of October 2021.
The storm destroyed hundreds of trees throughout town. They struck houses and smashed vehicles, and in certain areas, they caused lengthy blackouts. It took days to tidy up the debris of strewn branches and trees.
The powerful winds swept throughout Juneau. However, in the small region that surrounds Auke Nu Cove, the wind could have produced an erupting microburst that could cause a distinct damage.
Fritsch claims that a microburst is triggered with a powerful breeze that blows straight out of the sky.
“And it falls on the ground, and it strikes and then goes out every direction,” Fristch said.
When the wind blows outwards, they can reach 100 mph, generally causing lots of destruction within a tiny area. Similar to the one Escamilla discovered during the storm at Auke Nu Cove.
In other places, microbursts are linked to thunderstorms. When a storm develops an influx of warm air is raised to create clouds, which become massive as they are filled with hail or rain. If they are excessively heavy, they could release a massive wind that hurls towards the ground. It’s called microburst.
But storms aren’t commonplace in Juneau however, and that’s certainly not the case with the storm of October. Another possibility is much more fascinating. It’s all about the interaction between wind and the mountains of Juneau’s coast.
“We in business speak about straight-line winds, microburst wind and cyclonic wind, which are often associated with tornadoes. They are essentially they are circular.” Fritsch said.
Winds have basic, predictable directions, too. When a system is high pressure like the one that’s usually associated with clear skieswind patterns spiral clockwise, then outwards, creating gentle breezes. If a stormy low-pressure system is formed, the winds will spiral clockwise and inwards, increasing speed as they move.
These are the basic rules however they’re not enough for predicting precisely what the wind’s behavior will be.
“How do you make these winds flow in the manner they are?” Fritsch said. “The topography inside is the entirety.”
The weather — as with the other weather patterns that occurs in Southeast Alaska — is strongly influenced by the topography.
Straight-line winds are the most common type of wind. They’re powerful storm winds that move only in one direction. In the event of a storm they race through Gastineau Channel.
“So there’s a sea level there. Then we have 3,500 feet here, and the other side has 2,500 feet,” Fristch said, with a reference to Downtown Juneau as well as Douglas on the map. “And this is just the naturally flowing funnel.”
The funnel funnels powerful gusts over Mendenhall Peninsula and up the runway at Juneau International Airport — in the case of the October storm, for more than 24 hours. It prevented planes from landing and pushed a lot of the trees that lie at on the other side of the runway until the point of breaking.
Straight-line winds were the main cause of the tree falls that occurred during the storm, however the mysterious treefall in Auke Nue Cove can probably be connected to”the phenomenon of mountain waves..
When wind strikes the top of a mountain, it is pushed upwards. It then hits the stable air mass at the top of the sky pushing it downwards. These opposing forces make the wind to move in an upward and downward wave motion.
If there is a lot of intense winds, and there is a steady air mass surrounding Gastineau Channel, that wave action is what creates the infamous Taku Winds within downtown Juneau.
Mountain waves can also trigger microbursts. In some instances clouds can form beneath mountain waves. If the winds pass across the surface of a cloud the friction may result in the cloud begin changing direction.
“You don’t have to see it spinning like an elongated tornado,” Fritsch said. “But it’s rotating. This is the cloud of rotor.”
On the one side of the cloud near the mountain there strong updrafts, and on the other side, there are strong downdrafts. As the gusts move through mountain ranges, they could become caught in the rotating clouds, spiralling and accelerating into the downdraft-facing portion of the cloud. The downdraft could be able to break off and fall down in microbursts.
If this occurs, it has the potential for massive damage to the environment. Fritsch isn’t convinced that’s what did to the trees in Auke Nu Cove, but Fritsch says that’s the most natural explanation.
“It might have been because there was this air which hit on the Mendenhall Peninsula, and it was rising, and then it became stuck in a rotor” Fritsch said. “And at the opposite end of the rotor it fell directly down.”
Fritsch stated that the winds are leaving their marks on Alaska’s landscape daily.
“Somewhere there’s bound to be a wind anomaly in the vast massive, incredible state of Alaska that is likely to be unnoticed,” he said. “Because there’s no one there to witness it.”
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