Snow Forecast Maps

Storm tracking up through northwestern Ontario tonight will continue to produce a band of light to moderate snow...

Behind this storm, gusty winds will usher in enough cold air for lake-effect snow Friday into Saturday downwind of the Great Lakes. Not a major event, but notable since it is the start of the season. For a few hours a NW/SE-orientated Georgian Bay snow band might be able to extend down to Lake Ontario early Saturday.

------

Models are back on the idea that the Arctic Oscillation (AO) goes strongly negative by the end of the month, which forces the polar vortex of cold air much farther south compared to normal. The latest ECMWF model forecast valid for Thursday next week shows a very cold, Arctic air mass coming down the Prairies and directed toward the Great Lakes region.

Still more questions than answers in regards to the potential eastern storm (late Tue-Thur next week) as some models phase the two branches of the jet and force the storm up into the eastern lakes or Appalachians, while another solution is for no phasing and a the main storm exits off the Middle Atlantic coast and misses eastern Canada, but potentially nails parts of Atlantic Canada with wind and snow late Wednesday or early Thursday.

With the AO and to some extent the NAO trending negative it would argue for a more coastal track, rather than the inland one. Either way, once that storm moves by it opens the door to the cold blast into eastern Canada and the Northeast U.S.