If you're looking to pick up some cannabis at your local Ontario pot store for the weekend, prepare to be disappointed.

As legal recreational pot shops begin to open in Ontario Monday, operators are likely to face frequent inventory shortages given the tight supply and overwhelming demand seen in the early days of bricks-and-mortar stores elsewhere in the country, according to James Burns, chief executive officer at Alcanna Inc.

"If the volumes are even close to what we've seen in Alberta, and if there's only five stores in Toronto and there's 20 stores in Edmonton, that [inventory] will last a couple of days at the most – maybe less," Burns, whose company is based in Edmonton, told BNN Bloomberg in a telephone interview. 

Burns said Alcanna's Nova Cannabis store in Toronto was allowed to order 100 kilograms of pot before shops could open their doors on April 1. After that initial order, pot shops are allotted a maximum of 25 kilograms of cannabis products a week with orders fulfilled every Monday, he added.

Alberta pot shops are allotted roughly 13 to 16 kilograms of cannabis weekly, depending on what's available, Burns said. He added that amount of inventory only lasted less than a day before Alcanna's five Nova Cannabis stores sold out, meaning the shops were dry for the rest of the week until the next order was delivered.

"We'll have six-and-a-half days a week where nothing happens, except a few accessory sales," he said. "We're still doing good numbers even if it's just in a day, but you plod along for the rest of the week and you do it all over again. It's just unprecedented."

Amanda Winton, a spokeswoman with the provincially-owned and operated Ontario Cannabis Store, the authorized wholesaler of legal cannabis to the provincial market, said the organization will work with its 37 federally-licensed producer suppliers to secure supply for Alcohol and Gaming Commission of Ontario-authorized stores and the online website it operates. She declined to confirm the specific figures of how much cannabis the OCS wholesaler would ship weekly to individual stores.

“Given the national shortage of cannabis, the OCS has implemented temporary measures, including setting maximum order sizes that will provide retailers with equal access to the limited supply available in the marketplace,” Winton told BNN Bloomberg in an email.

“OCS will continue to monitor the supply situation and may make adjustments as required to better support sales trends that are emerging.”

Burns worries the limited supply won't do much to deter people from the illicit market, which often sells its product at a far lower rate than legal retailers. The illicit market accounts for roughly 80 per cent of total cannabis spending in Canada, according to recent Statistics Canada figures.

"Maybe [the OCS] will be flexible and see that the 25-kilogram limit is too small," Burns said. "We'll play it by ear once we get the store finally open."