If your waist and hip measurements went down you probably lost fat and gained muscle which is awesome! The scale isn't the best measure of health or fatness. If you lost an arm in an accident would seeing a lower number on the scale make you feel really good?
You could also be retaining water due to sodium-intake, muscle swelling, illness, or menstrual cycle. Plus, at 16 you're still growing and that's a whole 'nother ball game.
no longer morbidly obese: 257 met 10/15/2009
10% loss (27lb):243 met 01/31/2010
no longer severely obese: 224
10% loss (24.3):218.7