I know this is a kind of old post, but are you referring to a day in early October, 2011?
I only ask because we were there (I believe Oct 2-10) at that time and, while I am used to the typical mid-day showers, it rained for a ~1.5 day period like I had never seen before. It started one evening while we were in Epcot and came down so hard you could barely see. And the strange thing was it did not stop until the next night. I thought someone told me while I was there that it was a record rainfall of some sort. It rained a lot that trip, but nothing like that 24-36 hour period.
Maybe we met you at Epcot! We met a lot of folks while waiting around. We spent most of our time inside the Mexico pavilion. Much to my surprise, Epcot still put on Illuminations in the rain after a delay in which the rain died down a bit.
We went last year around the same time. We spent 5 beautiful nights in Vero and then headed up for 2 night at WDW. It rained during both of our 2 nights in WDW (including two trips to
MNSSHP)!
We are going again this year at the same time (9/28-10/6) and hope third times a charm!