Todd Hirsch of ATB Financial says that is likely to mean a loss of jobs, less investment in the energy sector and a modest decrease in housing starts.
Immigration is also expected to decrease compared with 2014.
Hirsch is forecasting that economic growth this year in Alberta will fall by about one-half to two per cent.
He cautions that swings in oil prices will determine how the situation will play out in the coming months.
Hirsch says low oil prices and a soft Canadian dollar will help some sectors of Alberta's economy, including agriculture, forestry and tourism.
"The economic picture painted by our research certainly shows a slowdown," Hirsch said in a release Wednesday.
"But it is not doom and gloom here. We're still on track with Canadian averages. We're just not full steam ahead as we have been in recent years."
Hirsch suggested the changing price of oil will make it challenging to make financial plans.
"Anything could happen, but we feel that the most probable scenario is one that returns oil prices to a reasonable range by the end of 2015."
He suggested oil prices will probably range between C$55 to C$70 per barrel.
The Alberta government created Alberta Treasury Branches in 1938 as a temporary measure during the Great Depression to give Albertans an alternative source of credit. It became a provincial Crown corporation in 1997 and changed its name to ATB Financial in 2002.