Damage caused to the plane's onboard sensors by a tropical thunderstorm seems to be the most likely reason for what could have led to the AirAsia flight 8501 losing control.
The flight path of the still missing aircraft took it through the 'intertropical convergence zone' (ITCZ) near the equator where trade winds in both hemispheres intersect, forcing moist, tropical air to rise and condense into clouds that form thunderstorms.
Cloud tops reach between 47,000 feet to 52,000 feet above ground level. Chances are that the plane, which was cruising at a lower altitude, was flying through clouds containing ice or supercooled water.
The resulting ice buildup on external sensors like the pitot tubes most probably played a role in the incident, says a Mashable report.
Pitot tubes measure air speed and feed the information into the craft's computer. This information is critical to ensure proper craft speed as flying too slowly causes the plane to stall and flying too fast can lead to a structural break-up.
The Indonesian Meteorology and Geophysics Agency (BMKG) has also said that QZ8501 was flying into an area of dense Cumulonimbus clouds before it disappeared, reports Guardian.
The Cumulonimbus clouds in the region had an altitude of 45,000 feet, said a BMKG spokesperson.
Cumulonimbus clouds are often associated with thunderstorms and intense weather.
The last contact from the plane at 6:13 am local time (23:13 GMT Saturday), was a request to ascend to 38,000 feet to avoid thick cloud.
The fact that flight 8501 was flying over a large swath of water with limited radar coverage and that aircraft GPS navigation systems do not broadcast their location to ground stations has made tracing the craft difficult.
The craft probably was not equipped with a continuous location reporting system, writes Forbes. Space-based radars are not available for civilian aircraft.
The Indonesian Search and Rescue team meanwhile is looking for remains of QZ8501 on the sea floor using a sonar system that can detect to a depth of about 1000-2000 meters. The Java sea over which the flight had travelled is a shallow region and sees heavy traffic.