That'd be GLOSEA - along with the full ECM-46, which is what's been driving the colder 15-30 day outlook for seemingly ages now. We can see a bit of the ECM-46 for free (via Iceland's Met Office - http://brunnur.vedur.is/kort/ec-ens/2019/01/24/00/ ), you can see a bit more if you pay for it (weather.us etc), but we can't see anywhere near the full picture.
They also have tools such as Decider, which acts as an ensemble of ensembles.
If push comes to shove, I'd always side with the Met Office on their long-ranger versus what we see on the mostly 15-day models we have access to.
Go on then, let's have your interpretation of those EC-46 anomaly charts. I'm sure we're all dying to know what you make of them! 
Originally Posted by: Retron