April-through-September Columbia River flows at The Dalles Dam on the Oregon-Washington border will likely be 110% of normal, the Northwest River Forecast Center said Tuesday.
The water-supply outlook at The Dalles has risen 10 percentage points since the start of the year, just 2 percentage points below the year-ago forecast, which was about 112% of normal. Week-ago flows at The Dalles also were forecast at 112% of normal.
Flows for the 2017-2018 water season at The Dalles have moved up in the rankings to 21 from 29 since the start of the year, compared with 1960-2018 historical data.
Mid-Columbia on-peak second-quarter packages are currently around $14.25/MWh, according to Platts M2MS data, up about 25 cents from a week ago. This sees Mid-C Q2 2018 packages trading about 15% above the $12.50/MWh where Mid-C Q2 2017 packages were trading a year ago.
Further upstream, flows at the Grand Coulee Dam will likely be 116% of normal, 9 percentage points above the year-ago forecast of about 107% of normal.
Grand Coulee flows for the 2017-18 water season are currently ranked 17, compared with 1960-2018 historical data.
Flows at Dworshak in Idaho are likely to be 116% of normal for this water season, 8 percentage points below the year-ago forecast of about 108% of normal. Since the start of the year, the water-supply outlook at the Dworshak has risen 15 percentage points.
Ensemble streamflow prediction forecasts compare historical and current data and run the information through model scenarios to project what water supplies could look like. Power-market participants closely watch the reports as an indicator of upcoming water supplies for hydroelectric generation in the Pacific Northwest.
(Corrects first paragraph to refer to Oregon-Washington border)
