My initial thoughts on this summer are it being another cool and pretty wet one, as im thinking this current La Nina is in it for the long haul. Which if it persists this summer, combined with the negative turning QBO i think it could give a cool wet pattern.
However if La Nina weakens away to leave neutral conditions in the Pacific then i think we could possibly get a decent-ish summer, maybe something along the lines of 2005, warm but with cool wet spells.
But i've also had some interest in the stratosphere the last few weeks, as it has been pretty cold the combination of that with +QBO has left us in this very dry and increasingly warm pattern, the ozone levels have too plummeted across the north pole which can cause stratospheric cooling, so with that in mind if the stratosphere stays cold during the next few months we could have a warm and very dry pattern persist through until summer and perhaps beyond, but that's just my novice thoughts .