B.C. could have atmospheric river rating system by early January

VANCOUVER -

The public safety minister has revealed British Columbia could have a rating system for atmospheric rivers as early as January, even though Environment Canada cautioned that might be an optimistic timeline. 

While University of California researchers have developed a one to five ranking system they regularly publish, much like those used for hurricanes, no government agencies have adopted the system – which could make B.C. the first. 

“The fact that Environment Canada is working on a ranking system that will allow us to have a better understanding of exactly what is going to be taking place is, I think, extremely important,” said B.C. Deputy Premier Mike Farnworth. “It will help us improve not just our notification but our response and help local governments, too, which are on the ground at the front lines, so that's all important."

Two more atmospheric rivers are headed to the province in the coming days.

When CTV News asked Farnworth whether the ranking system could help lead to B.C. finally utilizing the Alert Ready emergency text alert for flooding and other life-threatening weather events, as other provinces have been doing for years, he did not answer. 

Environment Canada not rushing implementation 

An hour after Farnworth announced the timeline, Environment Canada held an unprecedented technical briefing to describe the two atmospheric rivers sweeping toward the province and the implication for more water on soil fully saturated with the latest precipitation, which was badly damaged during earlier wildfires and drought in the summer.

“It is exciting, it’s just not quite ready,” said warning preparedness meteorologist and spokesperson, Armel Castellan, describing the January timeline as an internal government deadline. 

He said they are sending research to the American Meteorological Society as a flurry of behind-the-scenes work initiated to fast-track the implantation as a result of the widespread destruction of the mid-November atmospheric river.

“To be too quick to push that out would be irresponsible because it could have negative consequences so we want to take that very seriously and make sure that it's ready, that it can be socialized in the proper way, get the public education process going and make sure everybody is ready to take on that kind of rating system," said Castellan.

“At the end of the day, that’s where we want to be in that conversation, making sure that when we are raising an alarm or weather warning and it’s associated with a rating concept, it goes to behavioural change to save lives and property going forward.”

California university already issuing ratings

The University of California San Diego’s Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography developed the scale and is already publishing atmospheric river categorizations, while slowly building knowledge of the implications through media and agency outreach. No government organization has adopted the system yet. 

“Terrain on the west coast is very complex and when the atmospheric river is perpendicular to any mountain ranges, that’s really going to enhance the lift that’s caused by that terrain and can enhance the precipitation and can lead to significant enhancement of precipitation,” said Brian Kawzenuk, applications programmer at CW3E.

Kawzenuk and his team analyzed the system that brought catastrophic flooding and landslides to B.C. and concluded they were actually caused by back-to-back atmospheric rivers at category 4. They point out that the unusual route the weather systems took highlights the fact that the location and clustering of “families of ARs” can be more destructive than the AR5 that made landfall in California in late October.

At this point, they predict the incoming atmospheric rivers will reach B.C.’s South Coast at AR 1 or 2, with potential for AR 3 for the second one headed to Vancouver island, but he doesn’t want people to dismiss minor events or overreact to the term. 

“We don't want the public just because they see ‘atmospheric river' that they're panicking because the majority of them are beneficial,” he said. “We need to let them know when the big ones are coming, these are the ones that you need to be aware of and worry about."