Following several days of unseasonable cold and snow, this air mass is quickly sliding east with warmth pulling east across the country. As this cold air exits the East Coast over the next 24 hours and warmth follows, another trough is dropping south with a fresh lobe of arctic air set to flood a large portion of Canada. This next delivery looks to BRIEFLY shiver an area from the BC Rockies to the Maritimes and by late week, as the mother lode of arctic air sweeps down across Manitoba, Ontario and Quebec, temperatures could fall to between 25-35F below normal. According to the latest ECMWF run, it doesn’t get as far south or west down over the US as this one has. It appears to drop into the Dakotas and then kick east with colder air this time over the Northeast.

Ultimately, while brutal cold drives E,SE across Canada and skirting the Northern Tier of the Lower 48, the changes are already happening over Alaska with the ridge being replaced by a trough and the flattening out of the jet across the US which will drive Pacific air across the country. With this pattern evolving both over Alaska and the Lower 48, the arctic air will get shunted back north. Mid-October could well be very mild with no cold or very little to speak of. However storminess looks to greatly increase with Pacific storms likily to cross to the country and even the arif Pacific Northwest may get in on some autumn storms.

There are quite significant changes taking place with storminess resuming back over Alaska as well as a trough is returning which will usher in a return to winter here will bring colder air back to Alaska while the overall pattern turns more zonal beyond next week/weekend. A west to east flow looks to kick in for not only the US but for southern Canada. This would bode well with my idea of a flip to positive in the NAO/AO.

Have a look at the pattern for next week. Notie the brutal cold dropping down over Canada and then the complete turnaround which follows.

Here’s what the chart shows for next Sunday on into the following week!

Just look at how much Pacific air floods the majority of North America including a large portion of Canada. Only northern, arctic Canada is cold. This will also make for a return of very cold weather to Alaska and areas from the arctic circle north. In fact this will likely present the coldest weather so far for this northern region. By Tuesday 16th, the model shows ridging trying to pump very warm air up over the Dakotas and southern Manitoba while a trough drops into the Northeast, this may present cool, rainy weather here but certainly not cold. At this time, if this were to evolve, there is very little cold south of the arctic circle.