Canada: Pockets of exceptional water deficits to persist in MB, ON, QB, & NL

CANADA: POCKETS OF EXCEPTIONAL WATER DEFICITS TO PERSIST IN  MB, ON, QB, & NL (June 29, 2016)

The Big Picture
The outlook for Canada through February 2017 (below) indicates pockets of exceptional water deficits in northern Manitoba, eastern Ontario, central Quebec, and southeastern Newfoundland. Deficits of lesser severity are forecast across the Prairie Provinces and British Columbia.

Impacts
As drought in southeastern Ontario's Rideau Valley watershed becomes more severe the community of Perth is being asked to voluntarily reduce water use. Flows in the Rideau River are about 15 percent of their normal level for this time of year, reports the Rideau Valley Conservation Authority, while larger tributaries are 6 percent and smaller streams are intermittent or dry. The lowest May precipitation since 1928 was recorded in Kemptville, Ontario - 16.5mm compared to the long-term average of 84.8mm.

Though a state of emergency was declared in Dawson Creek, British Columbia as roads and bridges collapsed in some of the worst flooding in 30 years, the rest of the province is preparing for another year of drought as hot weather and low snow pack reduce water levels. The provincial government's River Forecast Centre estimates that “... (river water) flows are sitting at about one-quarter to three-quarters of what they would normally be this time of year.”

Forecast Breakdown
As indicated in the 3-month maps (below) for the same 12-month period, large pockets of exceptional deficits are forecast to persist through August in northern Manitoba, central Quebec, and southeastern Newfoundland. Deficits are forecast to emerge across northern Quebec, while surpluses – which in some areas may be exceptional – are forecast in southern Quebec. The extent of exceptional deficits in eastern Ontario is expected to shrink during this period; deficits may increase in extent in British Columbia.

From September through November water deficits are forecast to diminish in severity and extent across the country. However, moderate to severe deficits are forecast to persist in a wide stretch from British Columbia to northwestern Ontario with greatest severity in northern Manitoba and along rivers throughout the Prairie Provinces and the Rockies. Deficits in Newfoundland are expected to diminish considerably.

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