Models still can’t quite agree on this first major storm of the season.  They have been throwing numbers around from a couple cms in Southern Ontario to 20 – 25 cm for Ottawa an extreme Eastern Ontario.

Its a complex storm that develops a secondary low pressure from the storm that sets up over Northwestern Ontario on Saturday, like I noted in my last post.

Since this will be a rain to snow event and with temperatures near 0c and not a lot of extreme cold in the upper atmosphere, I think totals on the ground will be on the low side for most locations except where it snows with a stronger intensity.

Right now I am thinking the area from east of Ottawa to Brockville to Cornwall towards Montreal will get the most.  Possibly 10-15cm.  Elsewhere in Eastern Ontario could see around 5 cm maybe 10cm.

Southern Ontario will likely be 5cm and under, except for the Lake Effect regions around Lake Huron and Georgian Bay.  You could get near 10cm.  I am waiting for my weather friend Travis to update on Lake Effect, he is the expert on this beast!

Here are some of the snow totals from the various models. Right now the Euro model and the GEM model have the most snow for Eastern Ontario and the GFS model has the lowest. I can’t show the Euro snowfall accumulation map but it is in the 10-15cm range for areas around Ottawa and east.  Remember these numbers below are in inches.  Timing has rain starting late Saturday around Southern Ontario and early Sunday morning for Eastern Ontario, with a change to snow later Sunday towards the evening into Monday AM.  It will be a slow moving storm come Sunday night to Monday night:ecmwf_today



I will have a map out later tonight or tomorrow once we get more input from some the closer range models.  Temperatures will be around 0c to +2c all of next week so this could sort of stick around for Eastern Ontario. Another storm possibility around November 24th…