How bad was the flooding in the Pacific Northwest?

Floods and landslides have devastated the West Coast of Canada and the United States just months after a record heatwave, raising alarms about the worsening situation of climate change.

What is happening?

The Pacific Northwest is a coastal region located in the western part of North America. The largest cities in the region are Vancouver, British Columbia (Canada); Seattle, Washington and Portland, Oregon (USA).

Since September, heavy storms have dumped record amounts of rain on the wetlands of British Columbia (Canada) and Washington state (USA).

Floods engulf the city of Vancouver in the province of British Columbia, Canada.

The flood caused equally heavy damage in the Washington state area, USA. (Photo: ABC News).

Thousands of people were forced to leave their homes, others were stranded on roads cut off by floodwaters and landslides, and some towns were without power altogether. Mud and landslides have severely damaged major highways. British Columbia Premier John Horgan declared a state of emergency on November 17, and deployed military forces to rescue those still trapped.

The Port of Vancouver, the largest port in Canada, was forced to suspend all rail services, disrupting already strained global supply chains. The city itself is also completely cut off from the rest of Canada. At least one person has been confirmed dead and countless others are still missing.

In Abbotsford, a town of 160,000 people just east of Vancouver, many farmers ignored government evacuation orders and desperately tried to save livestock from rising waters, tying ropes around their cows' necks and pulling. they go to higher ground.

Desperate residents try to save livestock during rising water in the town of Abbotsford, Canada.

Desperate residents try to save livestock during rising water in the town of Abbotsford, Canada. (Photo: CBC).

Why was the flood so bad?

The area has been hit by unusually heavy rains since September, as one meteorologist has called them a 'parade of storms'. More and more rain fell than usual in Bellingham, Washington state throughout November.

This historic flood is the result of a combination of heavy rainfall and 'atmospheric rivers'. The 'atmospheric river' is known as a large dense band of clouds, compared with its width and length, it resembles a large river crossing the sky, carrying a larger amount of water vapor than ordinary clouds. That amount of water is enough to flood many cities for long periods of time.

"Atmospheric river" is a large cloud band as dense as a large river crossing the sky (Image: NOAA).

Hurricane scientist Jeff Masters described the phenomenon as 'a river in the sky, a pipeline that transports large amounts of water vapor out of the tropics'.

Flooding is made even worse by rampant logging, which affects slope stability, the rate at which water is absorbed into the ground, and the ability to hold soil in the root system. Without trees, heavy rains can wash large amounts of silt into nearby water systems, choking creeks and streams and causing them to quickly flood into residential areas.

Rampant logging in the province of British Columbia has made the flooding worse than ever.

The risk of landslides is also increased due to summer wildfires in the area. 'There is a very clear link between a bushfire occurrence and the risk of landslides,' ranger Thomas Martin warned. 'If you burn more trees, grass and shrubs, there will be less living things to stop the water flow. It will flow directly at great speed away from the mountain. Moreover, fire can make the soil dry, no longer able to absorb water, so the amount of water will flow out even more'.

What happened in the area this summer?

The storm is making landfall in the same area that just five months ago was hit by an extreme heatwave, causing wildfires that destroyed large swaths of forests. In June, the small mountain town of Lytton recorded a temperature of 49.6 degrees Celsius, pushing back Canada's national heat record.

Consecutive wildfires in Canada have destroyed the protective wall for residential areas. (Photo: NPR).

Multiple police stations and hospitals have reported a soaring heat death toll, reaching 486 in British Columbia and dozens more south of the border. Most of them are elderly and the main cause of sudden death is heat stroke.

The extreme hot weather is the result of an extended 'heat dome' over the Pacific Northwest. Although not an official term, 'heat dome' refers to a weather phenomenon created when high pressure in the upper atmosphere acts as a kind of lid, preventing hot air from escaping outside. Combined with the high temperatures inherent in summer, hot air sinks to the surface, causing extreme heat levels.

The 'heat dome' prevents hot gases from escaping into the atmosphere, causing the temperature in the northwest Pacific Ocean to reach a record high.

Links to the climate crisis

Scientists who analyzed heatwaves in the region found that human-caused climate change makes extreme weather at least 150 times more likely. Referring to both the heatwave and the storms, Joe Boomgard-Zagrodnik, an agricultural meteorologist at Washington State University, told NBC: 'It's usually very hot and dry in the summer, and public This rule has been reversed. They are certainly more in line with what climate models show for the future of this region - hotter, drier summers and wetter winters'.

Humans are the main cause of the climate crisis on Earth.

As the climate warms, scientists predict that "atmospheric rivers" will form successively and faster, growing more intense, becoming longer, wetter and wider. According to Environment Canada, there are five rivers in the atmosphere this season, a very unusual sign.

The way summer fires exacerbate winter floods is a prime example of a mixed climate disaster.