Monday night Update
The storm snowfall maps that we posted earlier looks pretty good for the storm that will impact Atlantic Canada later Tuesday and into Wednesday, though the northern area might have to be shaved a little bit.
Based on the latest information, I believe that the heaviest snow (15-25 cm) will fall from the southern third of New Brunswick through the northern third of Nova Scotia, including PEI and into central Newfoundland, which is slightly south of what the below maps showed from earlier Monday.
I also expect about 8-10 cm of snow in the St. John's, NL area Wednesday evening before a change to rain as warmer air moves in near the surface with the increasing east to southeast winds.
Even though I still think the snow will mix with and likely change to rain from Halifax to Sydney, the bulk of the precipitation will be in the form of snow with a quick thumping of snow late Tuesday night into Wednesday morning with a general 10-15 cm before the change.
Expect significant accumulations of snow (15-25 cm, locally 30 cm) from near Saint John to Moncton and into Charlottetown.
The map may be a little high on the amounts for the northern half of New Brunswick.
Accumulating snow for SW BC later this week
A storm system approaching from the WNW will run into a fresh, cold air mass over SW BC later Thursday night into Friday and the result will likely be accumulating snow for the Lower Fraser Valley of BC before any change to mixed precipitation or rain later Friday.
At this point, it is still too early to be specific on accumulations, but there is certainly the potential for at least 5 cm in Vancouver with higher amounts just inland and over the higher terrain.
Just finished updating these maps...here is our latest thinking on the clipper-type storm that will strengthen east of New England later Tuesday.
Computer models are still not in line with the track and intensity of the storm as it approaches Nova Scotia. A slight southward shift in this storm will bring the heavier snow into central Nova Scotia. At this point I favor 8-15 cm in Halifax with steady snow eventually becoming mixed with rain, but that could end up being adjusted.
I will have more comments about this storm this evening and other potential snow events later in the week over the West, including southwestern BC. There is also the potential for a storm over eastern Canada this weekend.
Smoke will continue to be an issue for interior southern BC and Alberta this week but changes in the pattern are looming.
Latest update on the long range into mid-September and a look at the Prairies storm.
Warm and dry conditions will continue to dominate in the West this fall.
Pattern change setting up this weekend into next week as the core of the very warm air shifts eastward into southern Ontario, Quebec and New Brunswick.
A fall-like storm system will bring steady rain and thunderstorms to parts of western Canada Friday afternoon into Saturday.
This is my latest interpretation of the weekly long range forecast model output into early September.