Environment Canada backing away from atmospheric river rating system

As a powerful atmospheric river begins sweeping toward British Columbia, CTV News has learned that the federal agency responsible for developing a ranking system for the weather events is now downplaying the benefits of such a system and suggesting it may not implement one at all.

Despite public comments from provincial officials and the agency’s own staff, Environment Canada said a scale to easily express the intensity or impact of the rain storms remains in the research phase, and downplayed the idea of a ranking system as unreliable.

The attitude is in stark contrast to the discussion of such a system a year ago, on the heels of widespread destruction from landslides and flooding caused by back-to-back atmospheric rivers in the province. At the time, the idea of an easily understood scale, like that used to categorize hurricanes, was welcomed by B.C.’s public safety minister and other emergency preparedness officials. https://bc.ctvnews.ca/b-c-could-have-atmospheric-river-rating-system-by-early-january-1.5677217

“This work is still at the research stage and it is not possible to say today whether it will be something that could be incorporated into operations at some point in the future,” wrote an Environment Canada spokesperson. “A rating scale would not improve the predictability of a storm system.”

The provincial government, which handles much of the big-picture coordination, supplies, and funding to respond to natural disasters has been depending on Environment Canada to develop the scale since it’s the agency responsible for meteorological monitoring.

“Obviously we would like to see a ranking system, a made-in-Canada ranking system,” said Public Safety Minister Mike Farnworth, when CTV News notified him that there were significant delays with a system he’d been anticipating would be ready by last January.

WHAT HAPPENED?

In November of last year, Environment Canada’s emergency preparedness meteorologist for B.C. told journalists there was significant work being done behind the scenes to meet what he described as an internal government deadline to implement a scale like the 1-5 ranking system used by American researchers and increasingly getting grassroots uptake from meteorologists and journalists across Canada and the U.S.

“It is exciting, it’s just not quite ready,” said Armel Castellan a year ago. “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.”

His peers have published academic papers in support of such a system, and a University of Victoria climatology professor championed the idea as a way of explaining the potential impacts to the public, with the same caveats and cautions we’ve become used to when it comes to hurricane rankings; namely, forecasted predictions subject to change.

Why Environment Canada would be luke-warm to such a common-sense approach to communication around atmospheric rivers is a mystery, since the agency refused CTV News requests for an interview to speak with someone on the matter to better understand why the shift in approach.

“There are many factors that will lead to flooding and cause damage and disruption that are not captured by the rating system including: quantity of snow in the mountains, moisture in the soil from recent rains, amount of water in reservoirs, height of the freezing level and wind speeds,” wrote a spokesperson via email.

The spokesperson suggested that since a ranking scale can’t take into account all the impacts, it is “therefore not a reliable measure” and that “applied scientists are investigating new formulations of an Atmospheric River rating scale to see if they can incorporate some of the other important impact factors.”

The scientists and researchers at the Center For Western Weather and Water Extremes at the Scripps Institution of Oceanography continue to offer forecasts on their 1 to 5 scale, which may become the de facto system the public and governments come to rely on in the face of Environment Canada delays and disinterest.

The incoming atmospheric river has been assessed as a 2 or 4 on their scale, with impacts varying from parts of British Columbia to Washington and Oregon states.