London → Santiago

Jet-stream exposure on this corridor is significant. Long mid-latitude legs mean clear-air turbulence is the dominant source of bumps, typically encountered at cruise altitude. The route crosses or passes near the Andes, which can generate mountain-wave turbulence downwind when upper-level winds are strong. At tropical latitudes, convective turbulence from thunderstorms is the main driver - pilots generally route around storm cells, but afternoon/evening flights encounter more build-up than morning departures. Westbound aircraft typically fly against the prevailing winds, adding flight time. Captains often pick altitudes that avoid the strongest headwinds, which can also mean picking cleaner-air altitudes.

Mountain crossings

Andes

Ocean / water segments

North Atlantic · South Atlantic · South Pacific

The oceanic track sees its strongest jet-stream activity in the relevant hemisphere’s winter, when winds aloft are fastest and clear-air turbulence is more frequent. This corridor is most turbulent in the relevant hemisphere’s winter, when the jet stream is strongest and sits closer to the route. Wind flowing over the Andes can generate mountain-wave turbulence that extends hundreds of kilometres downwind - most pronounced in the relevant hemisphere’s winter, when upper-level winds are strongest. At tropical latitudes, convective (thunderstorm-driven) turbulence dominates during regional wet seasons and monsoon cycles, typically worst in the afternoon and evening.

Peak turbulence

Regional wet season (varies by location)

Typically calmest

Dry season

LHR → SCL turbulence FAQ