Any ideas what causes water to pour out under passenger side dash/glove box area on a 2005 Dodge Grand Caravan?

Happened first time today, & did it
twice when I accelerated from a stop.
Just gushed out & soaked floor. I
turned off air & it hasn't happened
again, just an occasional trickle when
I take off. We did have a big rain last
night, but it has never leaked before.
Also, I've had to add water to radiator
& overflow resivoir in the past & have
not been able to tell where it's going,
no noticeable leaks...until the dash
gush today.