The 12z Euro deepens the system by 15 mb in 6 hours and 27 mb in 12 hours as it is leaving the US and moving into Canada. How impressive is that rate of deepening? Well, the 1978 Ohio superbomb deepened 16 mb in 6 hours and 30 mb in 12 hours... but it accomplished that at a farther south latitude from AL to Lake Erie. A little bit less impressive to do it where the Euro does, but still very impressive nonetheless.
That being said, this is still in model fantasy land and very much subject to change.