Peering back into Silver Surfer Black #4, first we take a look at the cover art that could be (and this is all a big what if until we get confirmation from the horse's mouth) Tradd Moore's artistic take on Black Winter where Norrin Radd, Silver Surfer goes back in time and witnesses Galactus birth from his incubator.
Now on to the interiors of the book. Black Winter is actually referenced by name but what follows is actually Galactus.
As you can see, the lights coming out of the clouds indicate eyes and then the next page is a two page spread of Galactus who emerged from the fire dark cloud depicted in the book.
So this begs the question, is it really Black Winter we are seeing or just the early stages of Galactus being born here? So we at Killerspec tweeted the best source to answer and hope we get a response.
So we can say Black Winter is definitely referenced in this book, which makes it semi-key. Until we get a final confirmation from the creator Donny Cates, we can just sit back and ponder.
If it does end up being Black Winter, well, I hope you got copies of Silver Surfer #4 and perhaps the likely hard to find 1:25 Peach Momoko Variant (which was already selling for a pretty penny), that book will explode.
Update: This was confirmed by Donny Cates that it is indeed NOT Black Winter. So we'll mark this spec as.....