Eastern Ontario and Southern Quebec should be on the watch for flooding as a pretty intense low pressure system tapping into moisture from the Gulf has moved into Ontario today, and ended up a bit further north than the models predicted. Below is the accumulations come Sunday morning from the GFS model:
Anywhere from 2-5 inches (50 – 120 +mm) of rain could fall in this area. I suspect near 80 – 90 mm for Ottawa, with higher totals from Brockville to Cornwall. This low pressure system will also combine with a tropical wave moving up the Atlantic to give some pretty stormy conditions for Quebec and the Maritimes.
The good news is the cold air that will wrap in behind this low pressure system that keeps the temperatures very low for Saturday into Saturday night shouldn’t give any snow to Eastern or Central Ontario, the higher atmosphere temperatures are cold enough, but it will be a matter of the temperatures being cold enough at the surface, and if there is any perception left to fall. Any snow should be confined to central Quebec but keep your eyes open from North Bay, Algonquin to Renfrew.
Temperatures will remain normal to below normal all next week (normal is around 10c). Most models predict things warming up near the weekend with a low pressure system arriving, but then again falling below normal behind this low pressure system by the beginning of November. However some long range models predict a warm up with a change to the pattern in the next 15 days into November: