With that storm we had here on 9-11 that left 2" of rain and piles of hail with high winds in 40 minutes, 3.5 miles to my east received hardly anything. This storm seemed to run SE to NW and, of course, I was in the middle.
15 miles is why I sited my station. The airport is about that far away and while I float away they report traces of rain - if any.