The dark and damp weather will continue across southern Ontario on Tuesday, putting a quick end to the days of sunshine and dry weather that has spanned much of September so far.
These back-to-back rain days will bring a widespread 20-40 mm across the region by Wednesday, with some areas in line to see closer to 50 mm. This has prompted a rainfall warning in some areas, with the risk for flash floods and water pooling in areas that see the heavier downpours.
RELATED: PHOTOS: Funnel cloud spotted over Brantford, Ont. on Saturday
Despite the rain, and brief tumble in temperatures, daytime highs will quickly rebound as we round out this week, and the month of September as whole. While it won’t feel quite as warm as the mid summer-like heat from last week, temperatures in the lower 20s are certainly warmer than normal for late September.
Forecasters will also be closely watching the remnants of a tropical system, which is expected to make landfall along the Gulf coast as a hurricane on Thursday. Will this interrupt your weekend plans in Ontario?
Tuesday into Wednesday:
An active storm track is helping to guide several low-pressure systems from the U.S. through Ontario this week.
Showers will spread across the Greater Toronto Area (GTA) through the afternoon and evening on Tuesday, then eventually to eastern Ontario by the overnight hours.
Thunderstorms are even possible in parts southwestern Ontario on Tuesday afternoon, with rain becoming heavier as a more unstable air mass moves in Tuesday night. Some of these storms could approach severe criteria with strong wind gusts. The thunderstorm threat will continue through the overnight, as they track through the GTA.
A rainfall warning is in effect, with the risk for localized flooding in low-lying areas.
“Heavy downpours can cause flash floods and water pooling on roads,” says Environment and Climate Change Canada (ECCC) in the warning.
By the time all is said and done, local rainfall amounts up to 50 mm are possible through Wednesday, with most locations recording between 20-40 mm.
Rain showers will linger into Wednesday morning, as well, though becoming much more isolated and lighter in nature.
Much of the afternoon should be rain-free for areas to the west of Toronto, with even some peeks of sunshine, and temperatures a few degrees above seasonal.
Thursday and Friday will be mostly sunny and warm, with temperatures hovering in the low 20s.
RELATED: Ontario welcomes fall with more summertime warmth, but will this last?
Eyes on a potential tropical disruption this weekend
A mix of sun and clouds is expected for this weekend, with warmer than normal temperatures, once again. The one slight disruption to a potentially spectacular fall weekend would be the remnants of a tropical system that’s expected to make landfall along the Gulf coast late this week.
RELATED: U.S. concerns grow over soon-to-be Helene as it eyes Florida Panhandle
At this point, we do not expect anything more than some high clouds with showers staying south of the border, however, there is still some uncertainty as the storm develops. If the remnants track further to the north, there could be scattered showers throughout parts of the weekend.
Warmer than normal temperatures will spill into the first half of the week, but a period of cooler weather is possible late week or weekend, and into the second week of October. A bump in warmer than normal daytime highs are expected to return for the second half of October.
Stay with The Weather Network for all the latest on your forecast across the region.