B.C.’s week splits in two with rain to start, heat to finish

British Columbia will experience the duality of weather this week as a raw and rainy setup to start the week gives way to a hot ridge of high pressure by next weekend.

Rainfall warnings continue for portions of the Lower Mainland heading into the work week as periods of steady rain wash into the South Coast.

The rain will stick around into Tuesday before conditions improve and tilt toward sizzling sunshine.

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Rain 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. Rain that arrived Sunday morning will continue through Monday afternoon.

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 parts of the Lower Mainland.

“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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The heaviest rain will feature rates of 3 mm per hour across the Fraser Valley through Sunday evening, raising the risk for localized flooding in this region.

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 mark of 83 mm in the gauge down in Victoria.

Agriculture and Agri-Food 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 rainfall on the way is great news to alleviate dryness and improve wildfire conditions.

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Another system is headed to the B.C. coast on Tuesday to bring additional rain, but it will be weaker in comparison.

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.

Header image courtesy of Unsplash.

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