(CNN) – Another atmospheric river will flow in western Washington and parts of British Columbia, Canada this week.
While back-to-back-to-back schemes seem a bit like a broken record for the region lately, the phenomenon is really significant.
Rivers in the sky have caused landslides to block roads, rivers to flood cities and, in one case, lead an old lake bed back into a lake.
In British Columbia, atmospheric river events typically occur in November, just like in the Pacific Northwest. The problem for both regions this year was the consistency of the systems without interruptions for drying.
“The first atmospheric river event hit us hard on November 13-16, bringing down an amount of 150-300 mm of precipitation in less than 48 hours,” said Johnson Zhong, meteorologist for Environment Canada.
In addition to fresh snow, it has rained as well, which exacerbated the flooding.
“There was up to 30-50 cm of fresh snow at an altitude of 1500-2500 meters,” he observed. “During one of our atmospheric river events, it rained much higher than 2500 meters, so the rain melted the snow and contributed to the flooding.”
One of the areas with the most flooding was the Sumas area, about 80 kilometers east of Vancouver.