We've all seen it: people set up tents, stick 3 or 4 stakes in the ground, and call it good. It doesn't look like rain...who needs a rainfly? I used to think of this as a rookie mistake, but recently, I've seen seasoned hangers do the same thing (you know who you are!), only to do the 4am scramble.
Well, now it's my turn. I came in yesterday with 100# of corn in my truck. With no rain in the forecast, I decided to leave it 'till this morning. You know what happened next. With over 1" in the gauge, and counting, the NWS said, "Whoopsie! Our computer didn't model this."
Takeaway: Tarps only work when they're hung and staked.