2016 US Open tennis tournament.
Except for the main stadium, the Open is an outdoor affair. So nothing chills an attendee's heart more than a forecast of "scattered showers."
What does that mean?
Fortunately, one of my fellow guests had the Dark Sky app.
Dark Sky is the weather app of your dreams - it alerts you up-to-the-minute with what nonsense Mother Nature has in store, its severity, and how long it will last - right over your head.
The app also provides unique radar imagery, unbeatable accuracy, and hyper-localized results.
This does not come cheap - about $4.00 in Apple's app store.
But there, at the Open, it made all the sense in the world. We knew that at a specific time, we could safely leave Arthur Ashe Stadium and watch matches in the open air Grandstand court.