A potent and impactful storm system will affect much of eastern Canada through Sunday with the threat for heavy rain, single digit temperatures and wintry precipitation in Ontario.

More rain to cap off weekend in Ontario, chance for wet snow

Find Your Forecast Search for a location

Digital writers

theweathernetwork.com

Saturday, October 22, 2016, 8:24 PM - Though the rain has stopped for most of the province, rainfall warnings remain in effect for eastern Ontario, with the chance for some wet snow.

The rain is due to a moisture laden low pressure system centred over Maine, which is tracking into southeastern Quebec.

Winter Sneak Peek: Classic Winter or green for the holidays? Exclusive first look at what the winter might bring this year. | FORECAST & MAPS HERE

QUICK FACTS:

Rain to taper off overnight Saturday.

Rainfall totals expected in the 60-90 mm range, with local amounts near 100 mm possible near Quebec border.

Colder temperatures reinforced early next week before another warm up for the final few days of October.

STORM TOOL KIT: Be prepared for severe weather with The Weather Network's online essentials: ALERTS | LIVE RADAR | UPLOAD PHOTOS/VIDEOS | LATEST NEWS | FOLLOW ON TWITTER | HIGHWAY FORECAST | AIRPORT FORECAST

Brisk northwesterly winds brought gusts of 40-70 km/h and lake-effect showers across southern Lake Huron and south of Georgian Bay Saturday.

Cornwall has seen the most rain in terms of accumulation, picking up 91 mm as of Saturday evening, with 49 mm recorded in Ottawa.

Parts of central and southwestern Ontario also saw brief bursts of flurries late Friday.

Light rain may be mixed with wet snow Saturday overnight in eastern Ontario, however, no accumulation is expected as the surface is relatively warm.

See the blue? That's a little bit of lake effect snow south of Georgian Bay. #onstorm #DundalkHighlands pic.twitter.com/lyuwOqjRQZ — Kim MacDonald (@KMacTWN) October 22, 2016

While temperatures are forecast to remain in the single digits through Sunday morning, daytime highs in the mid-teens are likely across southern Ontario. Showers arrive for the evening and overnight as a low moves in from the west.

Long range forecast

So far, October has featured well above seasonal temperatures from the Great Lakes to the Maritimes. High heat, severe thunderstorms and even a late season tornado have also been confirmed this month making things feel more like the middle of summer than fall.

As for the rest of October, Weather Network meteorologist Dr. Doug Gillham says there's "considerable" uncertainty in the long range temperature forecast from the Great Lakes to southern Quebec.

"Warmer than normal temperatures are likely for the central U.S. and that will spread into parts of the Prairies, but [there's] uncertainty as to how far northeast that will extend," Gillham said Friday. "Some individual runs of different models are rather chilly in the Great Lakes right through the end of next week, while the ensembles have milder weather making better progress into Southern Ontario and beyond before the final weekend of October and persisting into the first week of November."

Gillham says there's a likely chance a system will move out of the central U.S. toward the Great Lakes late next week, whose exact track will be be "one of the keys to the late week temperature pattern."

"Regardless of exact track, it looks like a period of unsettled weather around Thursday for the Great Lakes," Gillham says, adding forecasters will have to keep an eye on the northern edge of the precipitation area for signs of wet snow or a rain/snow mix.

The last few days of October and the first week of November may see a mild pattern, Gillham says, though he stresses it is too early to for a confident forecast for a specific day, such as Halloween, as it will depend on whether an individual weather system intrudes on the pattern.

Check back often for updated forecasts as the end of October nears