Rainfall warnings in B.C. precede a sharp mid-week heat ridge

It’s a pattern you don’t expect to see in the beginning of June, but it’s one we’re very happy to see to kick off the start of the summer season.

An unusual jet stream pattern dipping over British Columbia will bring a stretch of wet weather to the South Coast over the next couple of days. Some areas could see June’s entire average rainfall in just a few days.

Enjoy it while it lasts, though, as the hottest temperatures so far this year are just around the corner.

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Rain arrives Sunday, continues into Monday

A large low-pressure system over the Gulf of Alaska will force several disturbances to pinwheel into the West Coast over the next couple of days. The rapid succession of systems will arrive Sunday and continue into Monday.

Plentiful moisture flowing in from the south qualifies as a relatively low-grade atmospheric river, providing the juice needed to fuel steady rains across much of southwestern B.C.

A rainfall warning is in effect for Metro Vancouver and parts of the Lower Mainland ahead of the rain’s arrival on Sunday.

“Heavy downpours can cause flash floods and water pooling on roads,” Environment and Climate Change Canada (ECCC) said in its warning. “Localized flooding in low-lying areas is possible.”

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Widespread rainfall totals of 50-75 mm are expected across the Lower Mainland and Vancouver Island, with higher totals expected at higher elevations and lower totals in the typical rain shadow regions.

These are impressive totals for June. Average rainfall totals for the month hover around 50 mm for Vancouver, with about 70 mm in an average June for Abbotsford and only 29 mm in the rain shadow over Victoria.

Even so, it’s likely that this rainfall event will fall far short of achieving any monthly rainfall records. Vancouver’s biggest monthly rainfall total for June stands at 142 mm, with a monthly high-water mark of 83 mm in the gauge down in Victoria.

Agriculture Canada reports that the South Coast has seen 50-70 mm of rain over the past week. Raw and rainy weather is unpleasant at first, but it’s early June and we’re in wildfire season. Additional steady rain on the way is great news to alleviate dryness and improve wildfire conditions.

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This unusual pattern is going to flip in a hurry and tilt conditions toward the hottest readings of the season.

A sharp ridge building over the western shores of North America will send daytime high temperatures soaring by the middle of the week and into next weekend. Readings could climb into the 30s for the Lower Mainland, with readings pushing 40 south of the border.

Stay with The Weather Network for all the latest on conditions across B.C.

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