Whether or not the storm in the vicinity of the airport proves to be the ultimate cause of the accident only the investigation will reveal... however... any pilot in the position of this crew having visual evidence of a storm close to the field and hearing widely varying wind pronouncements over a very short period should know that micro-bursts and resulting wind-shear are a very likely hazard to be found in the area. It's our job to know.
Taking off into those conditions in my book is a non-starter and any accident resulting from that departure could be said to have begun to happen even before the aircraft became airborne... if an accident did not result from the actions of the crew then it could also be said that it was blind luck that they got away with it.
Vibration... possibly approaching stall.... Loud bangs...probably compressor stall.