1997 Dodge Caravan Bad Rain Leak

After a good rain, either as I begin driving or earlier, over a qt. Of water pours onto the carpet. Glove comp. Is dry inside. Seems tocome in just below it. How do I get to the area to be caulked?
No water came in til 200 mi. Ago, then with heavy rains came. Didn't begin with a small ammount and escalate.