United States

Snowstorm spreads East

March 17, 2013; 6:48 PM

Special Sunday p.m. update.....

The storm which has been producing steady snow over the southern Prairies will head towards the arrowhead of Minnesota on Monday.

A secondary, coastal storm will likely form near Long Island, NY on Tuesday and then track northeastward toward eastern Maine by early Wednesday.

Expect a general 8-15 cm (3-6 inches) across southern Manitoba through Monday morning, including Winnipeg, with locally higher amounts just to the north. However, even as the snow winds down midday Monday, the combination of increasing winds and low temperatures will result in widespread blowing and drifting through the day Monday, resulting in poor travel conditions due to low visibility and snow covered roads.

Farther east..........

Snow will spread from southwest to northeast across southern Ontario starting in the mid-morning in the south then getting up into the GTA around 3 pm or so.

This particular region (from the GTA on south/west) will likely be caught in between the storm over northern Minnesota and the developing one near the Northeast U.S. coast, so while there will be steady precipitation, it appears that the best dynamics for heavier precipitation will be over northern Ontario and from eastern Ontario/Quebec into New England then the Maritimes.

Snow will gradually change over to sleet then rain in the Windsor area by afternoon then the Niagara region sometime during the evening. I do thing the snow mixes over in London, but temperatures may hover at or below the freezing mark for the event.

In general, expect about 2-8 cm of snow from the GTA on south, but 2 cm or less south of London.

Areas right along the lake from Hamilton to Toronto will probably barely get above the freezing mark for a time Monday night, leading to a brief change to rain. Then as the winds shift and colder air works in late it will probably go back over to intermittent snow.

Areas such as Kitchener and just barely north/NW of Toronto itself could see the snow mixing with or changing to sleet for a time Monday evening, then back to snow Monday night. Again, most of the snow will be of varying rates and intermittent Monday night.

Snow might also mix with some sleet/ice in the Kingston area late Monday night for a few hours due to the downsloping wind.

This storm should be basically all snow north of a line from Goderich to Orangeville to New Market and just south of Peterborough to just north of Kingston.

Once into southern Quebec there will be some Atlantic inflow of moisture into the system so the snowfall rates will pick up on Tuesday.

The Accuweather.com snowfall map shows the expected snowfall from this storm as we head through Wednesday.

We may have to adjust the amounts higher across coastal New Brunswick, parts of Nova Scotia and PEI Tuesday night as I fear that a band of heavy precipitation will just surge northeastward before the lower level cold air leaves. Once that heavier band shifts northeast the snow might just end or change to drizzle, but not before a quick-hitting dump of snow. I will address this Monday morning.

Ski areas are no doubt reaping the rewards of this blocking pattern! Should be an extended season for many.

You can follow me with my quick updates on the storm right here on my twitter @BrettAWX

I will be more than happy to answer questions on twitter or this blog for the storm.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com