Flood warnings were issued for several major rivers in British Columbia on Wednesday as a federal scientist says record rainfall and alpine temperatures are consistent with climate change.
Armel Castellan, Canada’s Environment and Climate Change Advisory Prep Meteorologist, said fall floods in the immediate aftermath of extreme summer heat are in line with expected trends.
“Unfortunately, this is consistent with what climate change has been projecting for all parts of Canada, including the mid-latitudes here in BC,” he told a news conference on Wednesday.
“It is not to say that it is always going to be so extreme all the time, we will see breaks, of course. But the frequency, amplitude of these events and their longevity individually will continue to increase in the coming years and decades.”
In November, record rains were recorded in places like Abbotsford, breaking previous monthly records by about 99 millimeters. Weather stations at Nanaimo, Victoria, Abbotsford and Vancouver Airport broke all seasonal precipitation records for September, October and November combined, he said.
Temperature records were also broken Wednesday, and Castellan said they could break records for December.
High-altitude heat is particularly problematic because the snow cover is thin, meaning it melts more easily, increasing runoff, he said. However, La Niña, cooler-than-normal waters in parts of the Pacific Ocean, should reinforce snow cover starting in January, he added.
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The anticipated thaw was one reason the Hope District placed 114 properties along the Coquihalla River on evacuation alert Tuesday.
On Wednesday, Coquihalla was one of the main waterways where the River Forecast Center updated flood alerts to warnings, meaning that river levels have exceeded their margins or will imminently exceed them, causing flooding in adjacent areas. .
Flood advisories were also issued for the Chilliwack River, the Lower Fraser tributaries, and the Tulameen, Similkameen, Coldwater, and Lower Nicola rivers, as well as Spius Creek.
Fall floods, summer heat in British Columbia in line with #Climate Change: Meteorologist. #BCFlood #BCStorm
Rivers were expected to rise throughout the day and the center warned that conditions were changing rapidly.
The flood warnings come as southern and coastal British Columbia entered the end of severe weather that meteorologists have described as a “parade” of storms with dozens of weather warnings across the region.
There were four dozen evacuation orders in southern British Columbia communities due to flooding and another 11 orders for landslides.
Some of the new warrants issued Wednesday covered around 40 properties near the Birken community due to a landslide hazard.
There are 12 evacuation orders involving 350 households in the Fraser Valley Regional District in its coverage area from Boston Bar to Abbotsford. Another 1,664 houses are on alert, most of them in the Hatzic Valley, where numerous rivers and streams are about to overflow.
Near Agassiz, a debris slide temporarily shut down traffic on Highway 7, which is the same artery where motorists were caught between two landslides last month.
A landslide also disrupted some people’s travel home Wednesday night on Canadian Pacific tracks that left the West Coast Express train unable to travel east of Maple Meadows.
More than two dozen weather advisories remained in effect in southern and coastal British Columbia, complicating cleanup efforts from previous floods and landslides.
Public Safety Minister Mike Farnworth said the province is doing everything it can to make sure people and communities have the resources and support they need.
He said uncertainty and anxiety are common during such an extremely challenging time and urged anyone struggling to use publicly available mental health supports.
“Please know that you are not alone,” Farnworth said.
While there was a hiatus in the weather on Wednesday, Farnworth encouraged residents of southwestern British Columbia to prepare for more rain ahead of an expected respite on Thursday.
Dave Campbell of the River Forecast Center said the additional rainfall could generate higher flows in several rivers during the day.
The central coast has seen moderate river rises, as expected, while rivers were growing rapidly in Howe Sound and parts of the Fraser Valley, he said.
The risk of additional flooding in Abbotsford due to the overflowing of the Nooksack River across the border with the United States was reduced on Wednesday, it added.
Abbotsford Mayor Henry Braun suggested conditions had stabilized in one of the worst affected areas of the province, though officials would be keeping a close eye on it overnight and localized evacuation orders remained in effect.
“If the weather continues to cooperate over the next few days, we hope we can begin to lift these and potentially other evacuation orders in areas as they become clear,” he said.
The city had 540mm of rain in November, about a third of its total annual rainfall, he said.
Flood alerts were in effect for the central coast, south coasts and Vancouver Island.
Environment Canada says the rain should subside on Thursday and Friday, but a smaller storm system is expected to hit the south coast late on Friday.
Trans Mountain Corp. said its pipeline is “just days away” from restarting after a preventive shutdown on Nov. 14.
The company said in an update that the latest round of rain and snow has caused no new concerns about the integrity of the 1,150-kilometer pipeline, which carries 300,000 barrels of petroleum products a day from Alberta to BC.
BC has imposed gas rationing due to the closure of the gas pipeline. Many residents of the southern province have been told to limit each fuel purchase to 30 liters.
This Canadian Press report was first published on December 1, 2021.
Reference-www.nationalobserver.com