Feds Say It Is “Premature” To Create An Atmospheric River Classification System Promised By BC After Floods

When torrential rains last fall caused widespread flooding and wiped out major highways through British Columbia, the provincial government was quick to signal the creation of a classification system for atmospheric rivers.

But eight months later, Environment Canada and its scientists say there is still no timeline for when such a system could be operational.

“A decision on whether or not to implement such a scale as an operational information product would be premature at this time,” Environment Canada said in a statement.

Public Safety Minister Mike Farnworth said the province could have a usable rating system for atmospheric rivers earlier this year.

“This will allow us, I believe, to prepare ourselves more effectively. My expectation is, from what I have been told, that it will come. Waiting to be implemented in early January 2022,” he said at a news conference on November 22.

In the previous days, around 20 rainfall records had been broken across the province. Landslides closed the Trans-Canada Highway and other key roads, and the Sumas Prairie was flooded when the dams were overwhelmed.

The rain was brought by an atmospheric river, in which humid tropical air travels long distances in a narrow belt. On the west coast of North America, the phenomenon is known as the “pineapple express” because it tends to originate near Hawaii.

An infographic showing what atmospheric rivers are.  They are about 1,600 km long and 640 km wide on average.  An average AR can result in rainfall for a month in just a few days.
Atmospheric rivers are large, narrow streams of water vapor that travel across the sky. (CBC)

The meteorological office said it is studying various rating scales to reflect the intensity of atmospheric rivers with a numerical value, but “there are no immediate plans to formally adopt such a scale operationally in the short term.”

The BC Ministry of Public Security did not directly answer questions about an updated timeline.

But Environment Canada said it was instead focused on analyzing the “relevance” of such a system to Canada and noted that all new products must undergo rigorous evaluation and peer review to ensure validity and validity. reliability before implementation.

“This is essential for public safety,” reads a statement.

“Much more frequent in duration and more severe”

Roxanne Vingarzan, senior manager of applied sciences at Environment Canada, said the researchers aim to include five to eight levels in the system, but that it is “very much in its research phase.”

“It is essential that any proposed scale, or specialized product designed to assist in emergency management, meet the decision-making needs of public authorities. This includes ensuring that information relevant to the situation is timely, accurate and well understood,” he said.

One aspect of the study aims to understand how warm weather will affect the severity and lifespan of atmospheric rivers, Vingarzan said.

‘Climate models indicate that severe storms are expected to become much more frequent in duration and more severe. This is one of the motivating factors behind our project because we expect these atmospheric rivers to not go away and, if anything,’ it will have a bigger impact in the future, ” he said.

A man in a high visibility jacket walks among the puddles of water.
A contractor walks along a flooded street in the Huntingdon neighborhood of the Sumas Prairie flood zone in Abbotsford, BC on November 29, 2021. (Ben Nelms / CBC)

Ruping Mo, senior researcher and operations forecaster at Environment Canada, said the classification system would be based on the same forecasting system that generates current forecasts and alerts. He said current weather models can provide “confident” weather forecasts on the river up to five days in advance.

“We will not increase the accuracy of the forecasting model, but it can help better communicate the impact of the storm and perhaps give an early warning to operational forecasts,” he said.

Vingarzan added that although a new classification system would not increase accuracy, it would provide a historical context for “identifying its rarity and potential impacts”.

“The accuracy of forecasts depends on weather models, which are constantly being improved by the Canadian Center for Meteorological Research in (Environment and Climate Change Canada),” he said in an email.

‘First Nations and local authorities are the experts’

Meanwhile, Emergency Management BC said the province is ready to use the existing Alert Ready system.

“The atmospheric river assessment system is not the only determinant of issuing a warning,” reads a statement. “If one or more communities should feel that there is an imminent threat to life or public safety, the province is ready to use the Alert Ready system.

“The First Nations and local authorities are the experts in the field and emergency managers, at the local and provincial levels, will continue to coordinate closely.”

Alert Ready is available throughout Canada and allows officials to issue public safety alerts via television and radio stations, as well as wireless devices.

Although the system is coordinated at the provincial level, it is up to local government officials to use it. In extreme cases, the province can step in and sound an alarm directly, Farnworth said in May. He noted that while officials were ready to use it in some areas if needed last fall, it is now in place for use across the province.

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