A significant cold front will cross the Great Lakes Friday, potentially setting up a short lake-effect snow event Friday night into Saturday downwind of the Great Lakes.
At this early point, it appears that the primary wind direction will be from NW to SE, with the best potential for localized heavier snow late Friday night and Saturday morning.
This does not look like a major event due to wind shear and a shorter duration, but it is worth following since we are getting into the beginning of the season.
As we get closer to the event, I will pin down the local snow belt areas that will likely be impacted.
More snow for the Prairies
A weak, but strengthening storm system will spread an area of accumulating snow from south-central Alberta to southern Manitoba Wednesday through Friday morning.
This storm will likely bring a small accumulation of snow to the Calgary area Wednesday/Wednesday night, then between Regina and Saskatoon Wednesday night into Thursday.
As the storm strengthens farther east, the snow could get heavier over southern Manitoba later Thursday and into the early morning hours of Friday with stronger winds and potentially very low visibility.
I will draw up a map on this tomorrow.
Cold spreading out next week
Signs are pointing to the very cold air over NW Canada greatly expanding south and east by the middle of next week as the Arctic Oscillation tries to turn more negative for a time.
The GFS ensemble forecast for temperature anomalies (degrees F) below shows the expansive cold by Wednesday next week.
The question is whether or not the cold will persist or just hang out for a day or two. Right now, long-range guidance is not as excited about a blocking patterns as we head into early December and based on what I just looked at in terms of stratospheric temperatures and forecasts over the far north I would not be predicting any sustained blocking in the far north any time soon (next 10-20 days). Blocking patterns tend to force cold much farther north and can also lead to significant storms off the East Coast.
Keep the pools open! Warmth to prevail in the East for the next few weeks.
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Potential for significant rain in the western Prairies then severe thunderstorms in the eastern Prairies. Latest clues to the long range.