The hyper active tropics is not only allowing amplification of the mid latitude pattern but driving highs into unfamiliar territory! The high latitudes!

Hurricane Teddy looks to break away from the pack and run a due north course up into eastern Canada. This force high pressure north creating a downstream buckling and allowing the first autumn chill south into the British Isles later this week.

Essentially the bundle of heat that Teddy drives north will force both AO and NAO negative.

Today’s upper air pattern.

Wednesday

Friday

1st snows of the season arrive over the tops of the Cairngorms this week.

GFS ensemble day 1-5

Day 5-10

As the pattern progresses, this is a very interesting and textbook negative A0/NAO look by Sep 30th.