No one can correctly forecast wait times because the line can change very quickly. For example we met Phineas and Ferb and it took 6 minutes. As soon as Muppet Vision 3D exited, the line quickly jumped to 20 minutes. Another example: Cast Member forecasts the Anna/Elsa line at 3 hours and my friends were through in 1.5 hours. One tour group can cause a line to jump exponentially due to the small amount of people who can meet a character per hour.