MacKay made the announcement Tuesday at Canadian Forces Base Gagetown, where $5.1 million is being spent to expand the existing meteorological centre on the New Brunswick base.
He said the Gagetown facility will consolidate forecasting and briefing functions from Alberta to the East Coast, including the Arctic.
That will require the relocation of personnel, but he couldn't say how many.
Work on the project at CFB Gagetown began this spring and is scheduled for completion by June 2014.
MacKay said renovations will also be done to accommodate more personnel at meteorological and oceanographic centres at CFB Esquimalt and CFB Halifax.
Both of those projects are in the design phase.
He said as the capabilities of the Canadian Forces have grown, so has the demand for more sophisticated weather services to support personnel during operations at home and abroad.
"Our ability to plan around weather is key to conducting exercises and operations, providing search and rescue services and mobilizing for disasters and humanitarian relief."