From what I understand it was a large "airmass" area of almost tropical-like thunderstorms. I don't know what the feasibility of circumnavigating it was.. Looks like it could have been done but one of those things were they've driven through it a hundred times before with no problem.. Until there was a problem..

"Air France Flight 447 crossed through an area of tropical showers and/or weak thunderstorms with weak to moderate updrafts and a high likelihood of turbulence. The flight penetrated one cell at about 0150 UTC and then entered a cluster of cells beginning at 0158 UTC. The suspected zone of strongest cells was reached at 0208 UTC, which corresponds with the beginning of a track deviation, and another cell appeared to be reached at 0210 UTC, which corresponded with the time of autopilot disconnect. The flight was suspected to be within areas of showers and precipitation up until the time of impact, and the descent below FL250 into the critical -10 to -20 deg C zone probably involved some degree of clear icing on control surfaces, though it is uncertain whether this affected recovery of the aircraft, especially due to the short accumulation time that would be involved."

From This analysis..

And that is the scariest part.

I wonder how many aircraft accidents follow in the same footsteps.

[edit] the report beach is very detailed.. thanks.