50-100mm of rain is possible over the next 36 hours for parts of Northeastern Ontario.
A low-pressure system will develop in southern Indiana this morning and quickly intensify through the day. It will track northwards this afternoon and reach the Sault Ste. Marie region overnight. By Tuesday morning it will have dropped to near a 980mb low.
This will push heavy rain into Michigan through the day and into Northeastern Ontario this evening.
The low will stall out for nearly 24 hours near Sault Ste. Marie and this will allow for continuous rain to accumulate at 3-4mm per hour.
The area between Sault Ste. Marie and Sudbury could see isolated pockets of nearly 100mm. Many locations will see 40-60mm minimum.
This much rain this quickly could produce localized flooding and be a burden on culverts and drainage systems.
Watch for more updates throughout the day as this system develops and moves north.