Think I found the problem....rubber seal on outside at bottom of window track (the one that removable) that keeps window in the track has shrunk from sunlight/age and will need replacing. I put 50% pliable black sealant (stays 50% flexible even when dry) along the 1-2" gap until I can find replacement. Guessing this gap was allowing too much water running down the side to overflow the drainage trough/weep holes and spill into the camper. Don't worry; didn't fill the drainage trough or weep holes. I'll use a hose tomorrow when it dries to see if this was the culprit.
