Water Leaking - Front Passenger side from top - Nissan Altima 2005

Hi,
I have a Nissan Altima SL- 2005 and i have bought it recently from a owner. I have noticed water drops are dropping from the top at passenger side..It happens only when there rain and mostly when the car is parked..this does not happen when the car is on the move when raining.. And there was no leak when the care was washed (automatic)..
Guys Any idea...

Thanks..