When the kids were little we were in one of the bathrooms at a State Park. Caroline ran in and said, "There is blue sky, can we go swimming, now?" The rule was that it had to be 70 degrees to go swimming. Making this rule was the only way we could do anything but swimming!!!
A lady came out of a stall and told her, "That little bit of blue is a sucker hole, only suckers believe it is going to get nice out when they see one of those!"
The lady walked out and Caroline started big crocodile tears. I said, "Well sucker, let's go swimming!"
I can tell you from years of experience - when we see a sucker hole we are so happy. It usually does mean it is going to get nice.