"The territories' mining sector has wind in its sails, but economic growth is uneven across the regions," the board's provincial and territorial forecasting director Marie-Christine Bernard said.
"In the Northwest Territories, fewer developments in mining and declining diamond production are expected to weigh on economic prospects."
The outlook found Yukon's real GDP growth was expected to reach 8.1% this year and Nunavut's economic growth was expected to hit 4.4%.
It said Yukon's only remaining mine Minto now had an extended mine life, and three new mines - Coffee, Eagle and Casino - were scheduled to open in the next 10 years.
In Nunavut, there were three active mine construction sites this year, including Agnico Eagle Mines' Meliadine gold project.
"Nunavut's economy is on the cusp of an unprecedented growth spurt," the board said.
It said rising mining production would help create 2,000 new jobs in the next five years in Nunavut but less than half the roles would be filled by workers from the territory, with "a good proportion" staffed by fly-in, fly-out workers.
Meliadine is expected to start production in the second quarter of 2019 and is forecast to produce 5.7 million ounces over 15 years.
