Meteorological data for Beirut shows thunderstorm activity in the area during the time of the crashed Ethiopian Airlines Boeing 737-800's departure.
Weather information for Rafic Hariri International Airport around the time of take-off, 02:35, recorded winds from the northwest, with thunderstorms in the vicinity and a few cumulonimbus clouds at 2,000ft.
But the data also shows little other significant weather. Visibility was good with winds from the northwest.
Flight ET409 had been en route to the airline's base at Addis Ababa, with 82 passengers and eight crew members.
Ethiopian Airlines states that it has despatched a 14-strong team - including emergency response, medical, maintenance and security personnel - to the scene to assist the Lebanese rescue and recovery operation.
Latest from Twitter:
>