We were staying in a 2 bdr villa at Disney Institute in 2001 when Gabrielle (?) hit. It was 3 days after 9/11, so WDW was pretty deserted anyway (we were at MK on 9/11). Anyway, even though it was very windy and rainy, we decided to bite the bullet and go to MK that morning. We had a car, so we drove to the MK parking area. Got a great front row parking spot, 'cause we got there at opening time and no sane people were out and about anyway! We all put our rain ponchos on in the car, and I got out to set up the stroller and when I opened my umbrella, it immediately blew inside-out. Ok, so leave the umbrellas home during hurricanes, lol. My son was about 19 mos. old at the time, so we stuck him in the stroller and draped it w/ rain ponchos to keep out the wind and rain. The poor kid couldn't see a thing, but at least he was dry! Dh & I, dd (13 at the time) and the twins (4 1/2 at the time) just wore our ponchos and pretty much resigned ourselves to having wet faces, legs and feet all day.
Once in the park, it was eerily empty. There were a few other nutcases around, but not many. I remember being in Tomorrowland and looking across the plaza and only seeing maybe 10-15 people in the whole area. Needless to say, ALL rides were walk-ons! I also remember an announcement that morning calling for a moment of silence for the 9/11 victims shortly after we got there.
So, unless it's *really* bad and they actually close the parks, I'd say go for it and enjoy the low crowds. Just wear your ponchos, and maybe stick a few towels in your (waterproof) backpack to wipe your face with once in a while.
