On Camping if it pours on your tent it is a omen trekking is going to bad.
Portent tells something IMPORTANT is going to happen... (kuch-kuch hota hai)
when we ENTer airPORT we hear forewarning or some sorts of signs to go ahead
same meaning as portend. Port +end - at the end of port, you find dead bodies,which is a bad omen of something bad that is gonna happen in future.