Road crews and emergency personnel were busy Saturday, Feb. 1, 2020 as streets in Chilliwack were closed to traffic due to fallen trees and downed hydro lines as a result of strong winds. Pictured is a section of Vedder Road, just north of the Vedder Bridge. (Jenna Hauck/ The Progress)

Road crews and emergency personnel were busy Saturday, Feb. 1, 2020 as streets in Chilliwack were closed to traffic due to fallen trees and downed hydro lines as a result of strong winds. Pictured is a section of Vedder Road, just north of the Vedder Bridge. (Jenna Hauck/ The Progress)

Chilliwack saw slides and water pooling from ‘atmospheric river’ of rain

The storm total of almost 85 mm in Chilliwack included a record rainfall on Jan. 31

Chilliwack managed to escape some of major damage seen elsewhere in the Fraser Valley from the record rain in the “atmospheric river” event.

A couple small slides, localized flooding and ponding, but no damage to infrastructure was reported according to City of Chilliwack officials.

There was a small slide on Promontory Road Friday afternoon, and another that closed Marble Hill Road, both of which were cleaned up on Saturday, said Glen MacPherson, director of Operations for the city.

“There are small pockets of localized flooding and ponding water all around town, but the drainage systems caught up after the rain stopped,” MacPherson said.

The storm saw 84.6 millimetres drenching Chilliwack from Jan. 30 to Feb. 1 in an “atmospheric river” that saw prolonged rain come down in a narrow corridor of concentrated moisture.

That made for a record rainfall in a short amount of time, said Roger Pannett, volunteer weather observer for Environment Canada.

“On January 31, a Category 4 atmospheric river produced a record rainfall of 65.2 mm with strong and very mild, gusty winds, raising the temperature to 14.2 C, which was 9.3 C above normal.”

So the storm total was 19.4 mm on the Jan. 30 and then another 65.2m on Jan. 31, for a total of 84.6 mm.

An “atmospheric river” is a term coined in 1998 by MIT researchers, to describe the rivers-in-the-sky phenomenon. It’s when columns of moisture gather over the Pacific ocean in warm water plumes and travel in a band of vapor.

READ MORE: Promontory Road closed after small slide hit

Promontory Road was closed Friday afternoon after debris and mud came down the hillside with the heavy rain. It was closed again as crews worked for much of Saturday on removing trees that had become unstable.

More than 13,000 households were without power in Chilliwack on Saturday.

Any areas of Chilliwack being watched?

“Staff are monitoring pumping at the City’s drainage stations at Collinson and McGillvray and we were patrolling the Rotary Trail this morning looking for signs of high water flow damage,” the city official stated.

“A couple of sections of trail near the Southern Rail Bridge over the Vedder River were under water and Operations staff are repairing the trail surface today and tomorrow where gravel was washed out.”

The previous record rainfall for Jan. 31 was 42.4 mm in 1924.

The record 65.2 mm of rain on Jan. 31 included overnight rainfall to 8 a.m. on Feb. 1.

So the storm total was 19.4 mm on Jan. 30 and 65.2m on Jan. 31 for a total of 84.6 mm.

On January 31, with the record rain in Chilliwack, the total recorded rainfall for the month was at 127.1 mm compared to the 30-year average of 37.1 mm, so it was the wettest January since 2011, said Pannett.

READ MORE: Columbia Valley resident fed up with local road flooding


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Chilliwack Progress