WeatherWebb

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Weather conditions when QZ8501 went missing

on December 29, 2014

Sadly another plane has gone missing this weekend. Air Asia plane QZ8501 took off from Surabaya airport in Indonesia at 22:35 (GMT) on 27th December 2014 and was meant to land at Singapore airport at 00:30 (GMT) 28th December 2014. It went missing halfway into it’s journey at 23:24 (GMT) over the Java sea as illustrated in the map below. According to reports the pilot had asked to divert from it’s original course due to adverse weather and it is believed this may be the reason for the planes disappearance.

BBC map illustrating the flight path of QZ8501

BBC map illustrating the flight path of QZ8501

Indonesia and Singapore are positioned in the tropics as illustrated by the map below.  The tropics are positioned between the Tropic of Cancer and the Tropic of Capricorn. In meteorological terms, the tropics are the areas where the sun is positioned directly above at least once each solar year. Additionally, the trade winds converge in the tropics creating the Inter-Tropical Convergence Zone (ITCZ). The ITCZ moves northwards and southwards through the year and is responsible for heavy summer monsoons over Asia. This combination means that the tropical region is hot and moist all year round.

Map to illustrate the positioning of the tropics

Map to illustrate the positioning of the tropics

On 28th December 2014, when the QZ8501 went missing, there was a large amount of convergence across the area due to the hot conditions and moist air. This means that significant storms were developing. Locals in Indonesia and Singapore reported seeing billowing cumulonimbus clouds and heavy rain. Cumulus clouds develop when the sea or land is heated and warm air rises and then condenses in the atmosphere. These can then grow into cumulonimbus clouds by growing in height (up to 20km) due to the updrafts of water vapour and can further develop into supercell’s in the correct weather conditions. A supercell is a thunderstorm whereby the updraft rotates and these can be the most severe of all thunderstorm types. From looking at the EUMetSat‘s radar image below you can see that there was some very intense thunderstorms across the region bringing heavy rain, strong winds and lightning to the region. A picture showing lightning strikes detected in a storm close to where the plane went missing was put on twitter by @WeatherBug as illustrated below. The strong winds, heavy rain and lightning would have made flying conditions very difficult and could explain why the pilot asked to climb to 11,000m, to avoid the clouds.

Precipitation radar for SE Asia from EUMetSat

Rain amounts estimated based on cloud cover for SE Asia from EUMetSat

Image tweeted by @WeatherBug showing detected lightning strikes near the path of QZ8501 between 23:09 and 23:20 GMT

Image tweeted by @WeatherBug showing detected lightning strikes near the path of QZ8501 between 23:09 and 23:20 GMT

There are currently teams searching the Java sea near Belitung island by plane, helicopter and boat, and they are also likely to experience heavy thunderstorms and strong winds during the search. My thoughts are with the family’s and friends of those on the plane and I hope the plane is found soon.

 


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