We had an old dome style vent fan in the roof and the motor had been
shot for a couple years. A few weeks ago we finally got around to
replacing the motor and replaced the dome, too (it came with it).
Yesterday evening we had some storms pass thru and when i got home and
checked, the rain gauge said 4-1/4" of rain had falled. The covered
porch was soaked and a neighbor's tree had fallen so I assume the
winds were pretty strong, too.

When I went in the house, directly under the vent fan I found there
was a wet spot in the sheet rock of the ceiling. I didn't have time
to crawl up and look directly but I am assuming that the winds were
blowing the rains as we so happy call it, in to "horizontal rain" when
it's going almost directly sideways at about 40mph. Had this happen a
couple times before and it looks like the wind actually whips the rain
up under the dome of the vent fan and it drips from under the fan down
onto the ceiling of the master bedroom. The attic cooks in the summer
so the fan is a great asset. And we just had the roof completely
redone a few years ago so I doubt there's any issues with that.

Does anyone know of a good way to prevent this from happening? A pan
under the fan? Add some extra material to the edges of the dome?

Thanks!