Met Office Says "No-one in the World" Can Explain Weird Weather

My headline for today paraphrases matters only slightly. The exact words of Professor Stephen Belcher, head of the Met Office's Hadley Centre, were as follows:

We think that these are really some cutting edge science questions to be addressed here. No-one in the world can answer these questions, it's really important to emphasise.

as you can discover for yourself if you skip straight to about 4 minutues 35 seconds into the following video:

The occasion recorded for posterity was the "science workshop" held at the Met Office here in Exeter recently, on the topic of the recent "unusual seasons" in the United Kingdom. This may or may not have been the "meeting of top scientists to look at the urgent question of whether the warming of the Arctic is affecting UK weather" promised by the Met Office's Chief Scientist Julia Slingo a couple of months ago, although she was certainly present at the workshop. The Arctic was indeed mentioned by Prof. Belcher as one of the factors affecting the jet stream above the UK, which he described as:

A basket of things that can "load the dice":

1. The El Niño.
2. Solar variability
3. Things in the Atlantic Ocean, and there are processes high up.
4. A thing that has been talked about in the scientific literature a lot recently, which is as Arctic sea ice melts, can that affect the position of the jetstream?

Stephen then went on to go over the aforementioned "cutting edge science questions", which still need to be answered:

The role of the ocean having an imprint on the atmosphere, and setting the jet stream. There are things going on near the Gulf Stream that we need to understand better.

Things happening high up in the atmosphere in the stratosphere, above 10 km.

The role of greenhouse gas emissions and climate change.

In view of all that, perhaps Stephen and Julia would care to take a look at one or two other YouTube videos. Maybe one of the one's in which Professor Jennifer Francis talks about how the melting of Arctic sea ice affects the jet stream would be a good place to start?