It's been a while since we looked at the Ao and NAO forecasts into the summer. Remember that both of these are from the CFS model.
Heres the Arctic Oscillation. The forecast bit is the grey shading, what's happening in the past in the red shading. See how the grey shading over the coming 3-months in in negative territory. This hints at the westerly flow around the north pole being weaker than usual, this in turn leads us to suspect a disruption to the normal hemispheric circulation.
Now here's the North Atlantic Oscillation. See that this one bounces around neutral to negative territory. The hint here is that the usual westerly pattern across the Atlantic Ocean is disrupted and, when combined with the AO, confirms that higher pressure is likely to be in evidence this year in the Atlantic. Note it doesn't tell us where the high would be.
I talk more about what the CFS is actually forecasting for summer in yesterdays Look Ahead video. Use that in conjunction withy the above and you should get a better picture of where the CFS sees summer going.