Add a sudden rise in temperature to a forecast of buckets of rain coming on top of snow and ice, and Chilliwack could be looking at localized flooding.
It may happen, but residents shouldn't fear the perfect storm of eight years ago when record rainfall landed on record snowfall leading to mudslides in the Cultus and Eastern Hillsides areas, flooding in basements on Fairfield Island and elsewhere, and a situation so bad in Greendale the city called a state of emergency.
By noon Monday, the forecast rain had not yet arrived but Chilliwack residents were again reminded to clear the catch basins outside their homes as a warm and wet weather system hits the region.
According to Environment Canada, the cold temperatures that were a fixture for more than a month are about to be replaced by warm Pacific air originating in the Philippines.
More than 100 millimetres (mm) of rain is expected to fall over the next few days. Temperatures are also expected to climb to plus seven on Tuesday and as high as 12 C on Wednesday.
Additionally, the River Forecast Centre issued a high streamflow advisory for the south coast, including the Fraser Valley and including the Chilliwack River and surrounding creeks and tributaries
City of Chilliwack director of engineering David Blain said crews were out doing preparatory work, which includes putting the Collinson Pump Station in Greendale on its storm setting.
This also means ditches will be pumped ahead of time to avoid jamming from ice or debris in culverts.
And Greendale residents who remember 2009 will also be glad to know the city spent $2.5 million for a pump station upgrade in 2014 at Collinson, which flows into the Vedder Canal.
Also, even with 100 mm of rain, 2009 was a record year with much more precipitation. And there was more snow on the ground. On Jan. 5, 2009 there were 59 centimetres of snow, the largest total ever recorded for the city by that date.
Then, on Jan. 6 a record-breaking 83.7 mm of rain fell, another all-time record. On Jan. 7, a further 76.6 mm fell, another record.
Still, city hall said there could be localized issues with minor flooding and request residents and businesses to clear catch basin Monday and Tuesday as the rain arrives.
“Satellite imagery shows a plume of moisture originating near the Philippines streaming towards the BC coast,” said Environment Canada in a special weather statement updated Monday morning. “Rain associated with this plume is expected to begin today and to become heavy at times tonight. Strong southeast winds will accompany the storms. There is potential for the moderate to heavy rain to continue until Wednesday morning.”
Watch www.theprogress.com for updates as they become available.