A sucker hole is when a tiny, almost invisible patch of blue sky (on an otherwise "dismal" landscape) cons tourists into shedding their raingear, as they await the bright prospects implied. Unfortunately, they are usually premature--if not completely wrong-- in their quest for sun, and find themselves scrambling for that raingear again, as the sneaky deluge descends.
As for MM and me this morning....I guess you would say we're rather like the tourists, so hungry for sunny weather we are. We took the bait and went outside to feed the animals without raingear, just tempting the weather god to zap us, and guess what....? That patch of blue sky and fluffy clouds? It was a sucker hole.
By the way, Hydaburg Alaska, one of the villages where we taught gets somewhere around 155 inches of rain a year. That's why it's called a "rainforest."