When it comes down to it, nobody really has it nailed down exactly how the Earth's climate engine works, although more is being learned all the time.

If you wanted my W.A.G., I would suspect this has more to do with overall changes in major ocean currents than strictly temperature alone, although temperature would be a baseline driver. Changes in the jet streams can make dramatic differences in weather on land. Same for the oceans.

"Global warming" is not as accurate a term as "climate change." Some places will get warmer as planetary temperatures increase, some place colder, some places drier, some places wetter. And not the obvious places, either.