Canada: Water deficits persist in central QC, southern ON; surpluses southern BC

31 January 2017

The Big Picture
The outlook for Canada through September 2017 (below) indicates exceptional water deficits across the center of Quebec and its shared border with Ontario, southern Newfoundland, and northeastern Manitoba along Hudson Bay.

Deficits of varying severity are forecast for the remainder of Quebec, northern British Columbia, northern Alberta, New Brunswick, and southern Nova Scotia. Surpluses are forecast for the central shared border region of Saskatchewan and Manitoba, northwestern Saskatchewan, and southern British Columbia.

Impacts
The Insurance Bureau of Canada says that 2016 was a record-breaking year for insurable damages from natural disasters in Canada, which reached CAN$4.9 billion (US$3.76 billion), and is appealing to all levels of government to improve climate policies and preparedness.

The Red River Basin Commission is advising Basin communities in Manitoba to prepare for spring flooding, citing precipitation, ground saturation, and snow-pack, and is also monitoring water levels in the Assiniboine River which flows into the Red at Winnipeg. According to the Hydrologic Forecast Centre of Manitoba Infrastructure, soil moisture in the Red River Basin was normal to well above normal when the soil froze, leaving little room for further absorption. Water levels in the Assiniboine are currently record-breaking in some areas. Climate change experts say the Basin can expect longer, wetter springs followed by longer, dryer summers.

A three day snowstorm dumped nearly 80 centimeters (31.5 inches) on Chilliwack, British Columbia, closing schools and creating treacherous driving conditions that sent a snowplow sliding off the Trans-Canada Highway.

Though winter precipitation has improved lake levels and water flows in the Kawartha watershed of Central Ontario since a 2016 drought, the region’s conservation authorities have asked residents and businesses to continue voluntary reduction of water consumption since ground water supply is not expected to improve significantly until spring.

Forecast Breakdown
The 3-month maps (below) show the evolving conditions in more detail.

The overall pattern of the forecast for January through March indicates that conditions will be similar to those observed in the prior three months. Exceptional water deficits are expected to persist in a vast expanse of central Quebec surrounding Lake Mistassini; in southern Newfoundland; and in Northumberland County, New Brunswick. Deficits ranging from severe to exceptional are forecast in the following regions: from Lake Abitibi in Ontario south around Georgian Bay to Lakes Ontario and Erie; northwestern Ontario; northeastern Saskatchewan and eastward through northern Manitoba to Hudson Bay; central and northwestern Saskatchewan; and northern British Columbia.

Surpluses are forecast across Ontario from the southern Kenora District in the west to the border of Quebec south of James Bay, and may reach exceptional severity in many places. Exceptional surpluses are also forecast in: Manitoba from the Nelson River near Hudson Bay reaching west and southwest to Lake Winnipeg; surrounding Churchill Lake in northwestern Saskatchewan; and in the Columbia River Basin in southern British Columbia. Surpluses are also forecast along the Saskatchewan River and its southern branch.

The forecast for April through June indicates a clear transition from surplus to deficit across Ontario, most of Quebec, and into Labrador and Newfoundland, with the exception of the island of Newfoundland which will transition to relatively normal conditions. Deficits will persist in northeastern Manitoba, and will continue to emerge in central and northern Alberta, and surrounding Prince George in central British Colombia. Most surpluses noted in the January through March forecast are forecast to diminish in extent and severity from April through June.

After June the forecast indicates the persistence of primarily moderate deficits throughout much of the country, with greatest extent and severity in Quebec.

(It should be noted that forecast skill declines with longer lead times.)