Massive storm will drop entire summer’s worth of rain on Metro Vancouver
Environment Canada is predicting a massive shift in weather patterns, bringing virtually non-stop rain from Friday morning through to Monday. Between 80 and 140 mm of rain could fall between Friday and Monday
BY BETHANY LINDSAY, VANCOUVER SUN
METRO VANCOUVER — If the forecasters are right, this weekend is going to be a soaker in Vancouver.
Environment Canada is predicting a massive shift in weather patterns, bringing virtually non-stop rain from Friday morning through to Monday. The Vancouver Sun spoke with meteorologist Matt MacDonald to find out the five things you need to know about the coming deluge.
“It’s a pretty interesting system. It’s a big upper low that’s going to cross the south coast over the weekend,” MacDonald said.
The storm will be tapping into some leftover moisture from Tropical Storm Kilo, which hit Hawaii earlier this week. That extra vapour will deliver “copious” amounts of rain.
The storm will also bring slightly cooler temperatures in the 18 to 19 degrees C range, as well as windy conditions.
What to expect
Between 80 and 140 mm of rain could fall between Friday and Monday. To put that in perspective, the Vancouver area has only seen 41.6 mm since the beginning of June, and an average July or August has just 40 mm.
“This will be quite an impressive storm,” MacDonald said. “To get this type of storm is something you see typically in October or November, but to see this at the end of August is something else.”
The good news
“It will do wonders for the drought conditions,” MacDonald said.
The four-month period from April to July was the driest on record, with only 87.4 mm of rain. After those extremely parched months, this storm looks like it will bring total summer precipitation back up above the three-month average of 126.2 mm.
The storm will also be a relief for the Interior, where wildfire smoke from Washington State has caused hazy brown skies all week.
“This incoming storm will flush out all that smoke,” MacDonald said.
Southeastern B.C. won’t see the torrents of rain predicted for the south coast, but the expected 20 to 30 mm will definitely help with some of the local wildfires.
On Friday, the B.C. government rescinded the campfire ban throughout the Coastal Fire Centre because of cooler and wetter conditions in the forecast.
The bad news
All these long, dry months mean that the soil has lost much of its capacity to absorb water, which means a lot of the rain will just run off the surface. That could lead to flooding, landslides and blocked culverts.
Meanwhile, the drought has allowed contaminants to build up on the surface of the soil.
“All this rain is going to flush all of those contaminants into the rivers and into the oceans. From a water-quality perspective, there’s likely to be impacts,” MacDonald said.
Driving conditions may also be a bit hairy. During dry times, grime builds up on roadways, and when the rain hits that dirt, the streets and highways will get very slippery.
This weekend’s downpour will have many Vancouverites breathing a sigh of relief, but meteorologists are warning that the stage could already be set for another drought next summer.
Warm sea-surface temperatures near the equator are expected to bring the strongest El Niño season in almost two decades. That could mean above-average temperatures this winter and about 10 per cent less precipitation.
And even if the region experiences normal levels of precipitation, the warmer weather could mean that a large proportion of that falls as rain rather than snow.
“Fast forward to next spring, and we may not have much snow in the mountains to melt and in B.C., we rely a lot of snow melt to fill our rivers and reservoirs,” MacDonald said.
- Feb 01, 2024
- Nov 16, 2023
Our recent Annual Conference held on October 26th & 27th, 2023 at the Prestige Lakeside...
- Sep 13, 2023
We're hiring! The WSABC is looking for a contract Executive Director. This position looks after the society's...