If the variant continues to spread widely, the modelling table said, the doubling time for cases in the province could drop down to just 10 days.
Brown said survey data shows two-thirds of Ontarians are following public health rules such as physical distancing and wearing masks, but a third of the population are still bucking the restrictions.
Premier Doug Ford said while making the announcement, "The system is on the brink of collapse".
Ontario, meanwhile, reported 2,903 daily cases Tuesday with 41 more deaths in the province.
Ontario is not alone.
One of the main calls from the opposition and various advocates has been introducing paid sick leave so they can have more protections, especially if they work in essential workplaces and congregate care settings, including from the Toronto Board of Health.
Projections put ICU occupancy around 500 beds by mid-January with the potential of over 1,000 beds in February "in more severe but realistic scenarios".
Effective January 14, at 12:01 am a stay at home order will be implemented.
Windsor Mayor Drew Dilkens says he fully supports the new restrictions.
Premier Doug Ford also announced that retailers will be subject to shorter operation hours meaning all non-essential retail stores, including hardware stores, alcohol retailers, and those offering curbside pickup or delivery, must open no earlier than 7 a.m. and close no later than 8 p.m.
Windsor-Essex has seen almost 10,000 cases of the virus since March. Forecasts suggest more deaths in wave 2 in long-term care than in wave 1.
"The provincial and federal governments have been forced to make some impossible decisions", he said in a statement.
Health Canada is reviewing two other vaccines but can't make a decision about either AstraZeneca's or Johnson & Johnson's candidates until they report on their USA trials. The vaccination clinic at the Ottawa Hospital remains paused as of Tuesday due to a diminished supply of vaccine doses.
Canada has options to buy even more from both Pfizer and Moderna but those deliveries wouldn't come until late this year or even into 2022. Twenty-three of today's deaths were long-term care residents. Brown showed us and if that isn't scary enough, I don't know what is.
About 40 per cent of all long-term care homes in the province are dealing with an active COVID-19 outbreak and since January 1, 198 long-term care residents have died after contracting COVID-19.
If we do hit the 5% level of growth, which is quite possible, we'll be looking at over 20,000 cases a day.
"The COVID-19 Response Framework (colour-coded zones) is paused during this time", reads a note at the top of the province's public health measures breakdown.
These enhancements are in addition to the existing health and safety measures already being implemented in child care settings across the province.
Brown said the United Kingdom variant known as B.1.1.7, which is 56 per cent more transmissible according to recent studies, could accelerate case growth further.
While more contagious, the variant is not considered more lethal or immune to vaccines.
The province has also announced new restrictions for the construction industry.