Safety Investigation Report 2018:1 Factual Information/1.7
SAFETY INVESTIGATION REPORT MH370 (9M-MRO)
1.7 METEOROLOGICAL INFORMATION
1.7.1 Meteorological Situation
Climatologically for the month of March, the position of the sub-tropical high is located over the Gulf of Thailand. The weather is generally dry with very little clouds. The winds are generally light from the surface to the height of 40,000 ft above sea level.
The infra-red image taken by the geostationary satellite Multifunctional Transport Satellites (MTSAT) 1R of Japan Meteorological Agency (JMA) at 1732 UTC 07 March 2014 [0132 MYT 08 March 2014] (Figure 1.7A [below]) showed that there were no significant clouds at the last civil radar point at 1722 UTC, 07 March 2014 [0122 MYT, 08 March 2014].
Figure 1.7A - Infrared Satellite image taken by MTSAT at 1732 UTC 07 March 2014 [0132 MYT, 08 March2014]
Source: Malaysian Meteorological Department
The meteorological radar image taken at 1722 UTC, 07 March 2014 [0122 MYT, 08 March 2014] (Figure 1.7B [below]) showed that no rain occurred at the last civil radar point.
Figure 1.7B - Meteorological Radar Image at 1722 UTC 07 March 2014 [0122 MYT, 08 March 2014]
Source: Malaysian Meteorological Department
No lightning discharges were detected by the Lightning Detection System of the Malaysia Meteorological Department at the vicinity of last civil radar point from 1600 to 2159 UTC, 07 March 2014 [0000 to 0559 MYT, 08 March 2014]. Figure 1.7C (below) Blue symbol shows the lightning detected 1700 UTC to 1800 UTC, 07 March 2014 [0100 to 0200 MYT, 08 March 2014].
Figure 1.7C - Lightning Detection Map from 1600 to 2159 UTC 07 March 2014 [0000 to 0559, 08 March 2014]
Source: Malaysian Meteorological Department
The Meteorological Aerodrome Report (METAR) issued at 1600, 1700 and 1800 UTC [0000, 0100 and 0200 MYT, 08 March 2014] from Kota Bharu Sultan Ismail Petra Airport (WMKC), Kuala Terengganu Airport (WMKN), Penang International Airport (WMKP) and KLIA (WMKK) (Figure 1.7D [below]) did not report any significant weather phenomena.
Figure 1.7D - Locations of METAR Reports
Source: Malaysian Meteorological Department
There was no direct observation of the wind conditions at the last civil radar point, the closest upper air observation was at the Kota Bharu Meteorological Station, taken at 1200 UTC, 07 March 2014 and at 0000 UTC, 08 March 2014 [2000 MYT, 07 March 2014 and 0800 MYT, 08 March 2014] respectively, both reported a temperature of -40oC and wind from the north-east at 15 kt or less at 36,000 ft above sea level.
1.7.2 Comments on the Information Available
- 1) Forecast Charts
- a) Significant Weather Chart
The Significant Weather Chart (SIGWX) PGCE05 EGRR 061800 issued by World Area Forecast Centre (WAFC) London Fixed Time Prognostic Chart ICAO Area G SIGWX for FL250-630 (25,000 ft to 63,000 ft above standard sea-level pressure) valid 1800 UTC, 07 March 2014 [0200 MYT, 08 March 2014] showed that the filed flight plan route (red dotted line - Figure. 1.7E [below]) passed through a westerly jet stream with wind speed of up to 150 kt at latitude 30°N at FL390. Another westerly jet stream with wind speed of up to 100 kt at FL310 at the destination. Light clear air turbulence (CAT) might be expected from 25°N onwards to the destination. However, no significant adverse weather phenomenon was expected for the whole planned flight route.
Figure 1.7E - Significant Weather Chart PGCE05 Issued by WAFC London Fixed Time ICAO Area G Prognostic Chart SIGWX FL250-630 valid 1800 UTC, 07 March 2014 [0200 MYT, 08 March 2014
Source: WAFC London
- b) Wind and Temperature Forecast Chart
The wind and temperature forecast chart PWGE25 for FL340 valid 1800 UTC, 07 March 2014 issued by WAFC Washington showed the jet stream as in the significant weather chart above. The forecast winds at the last civil radar point and last air defence radar point were below 20 kt (Figure 1.7F [below]).
Figure 1.7F - The wind and temperature forecast chart PWGE25 issued by WAFC Washington for FL340 valid 1800 UTC 07 March 2014 [0200 MYT, 08 March 2014]
Source: WAFC Washington
- a) Significant Weather Chart
- 2) Significant Meteorological Information
Significant Meteorological Information (SIGMET) 3 was issued for the GUANGZHOU FIR valid from 12:45 to 16:45 UTC, 07 March 2014 [0200 MYT, 08 March 2014] indicated a thunderstorm forecast north of latitude 27°N and moving eastwards at 50 km/h in the layer with cloud tops at FL260.
- 3) Volcanic Ash Advisory
Volcanic ash advisories issued by Darwin Volcanic Ash Advisory Centre (VAAC) on 07 March 2014 at 06:27 and 18:37 UTC [2045 MYT, 07 March 2014 and 0045 MYT, 08 March 2014] for Sinabung (Sumatra, Indonesia) highlighted volcanic eruption located at 3.10°N 98.23°E (Figure 1.7E [above]) and volcanic ash plume observed up to FL120 and the plume was extending toward the west.
1.7.3 Availability of Meteorological Information
The necessary meteorological information was made available to the crew.