A storm will quickly move out of the Rockies tonight and tomorrow then track up toward New York State later Saturday. You can also follow my commentary on the storm via my twitter @BrettAWX
The storm will produce a narrow area of heavy snow just to the north of the track from very late Friday night through Saturday evening in southern Ontario and Saturday afternoon/night from Quebec to New Brunswick.
This will not be a wound up storm, so I do not expect drifting to be a major problem.
This storm will be mostly rain for the coastal Maritimes.
Based on the latest information, it appears that 15-25 cm of snow is possible from just north of Windsor, Ontario, through London to just north of Toronto and then up into the Ottawa region.
I like 12-18 cm for Toronto at this point. Obviously, a slight farther north or south track will have a definite impact on amounts and I will keep you posted on that through tomorrow with any changes to the accumulation map. Light snow should begin in the GTA sometime mid-morning Saturday with the heaviest snow late in the afternoon and early evening.
Montreal and Quebec City should also see significant accumulations on the order of 10-17 cm late Saturday afternoon/night.
Due to the track being very close by, there is a chance that the snow changes over to a mix or rain along the north shore of Lake Erie, through the Niagara region and then perhaps up near Kingston, Ontario.
Snow will also likely change over to a mix or rain over extreme southern and eastern New Brunswick/PEI (coastal areas) late Saturday night.
Also, a weakening front coming in from the west tonight will bring a general 2-5 cm of snow over parts of Ontario and Quebec.
Larger, more moisture-laden storm next week
The potential exists for a significant storm (in terms of moisture) to impact eastern and parts of Atlantic Canada next week. Right now, consensus is good for a storm to track up the west side of the Appalachians and gradually weaken as it approaches New York State. As it weakens a secondary, coastal storm may form near southern New England, but at this point, based on the jet stream pattern, the interior storm looks to be the main player.
This could be the type of storm that brings a heavier snowfall from the Midwest U.S. through parts of southern and eastern Ontario and then into southern Quebec and eventually New Brunswick.
If the secondary, coastal storm ends up developing faster and stronger (which I doubt at this point) then there could be more snow for the Maritimes.
This storm will be running into a cold air mass out ahead of it, so most places in should at least get some accumulation, even if there is a changeover as warmer air will be moving in aloft with the strong warm-advection.
Way too early to give snow accumulations, but just wanted to give the heads up.
Update on weekend snow and a look at the long range.
My thoughts on the overall pattern into next week....
A small, but intensifying storm off the New England coast will track northeastward through the Maritimes by Wednesday.
Weather highlights into next week
The storm impacting parts of eastern Canada later tonight and into Saturday with snow will move fairly quickly and will not be all that intense, but it will have a decent amount of moisture with it.
Some hope may be on the horizon for those freezing in the East