There has been plenty of confirmation that major thunderstorms were in the plane’s flight path, and the following analyst believes there was lightning as well, based on the other confirmed attributes of the storm systems, and explains why definitive confirmation may simply not be available.
http://www.weathergraphics.com/tim/af447/
The point of this article is it DIRECTLY contradicts the other articles claims of 100 mph updrafts, violetn thunerstorms AND lightning in the area. Go to the link of the article and you will see a Brazlian who tracked lightning strikes that night and shows there were none in the area of the plane.