CX253 turbulence forecast
Cathay Pacific · Hong Kong (HKG) to London (LHR)
Next departure at its usual time · Sat 7 Nov, 13:25 Hong Kong time
This date's schedule isn't confirmed yet. This is the air CX253 flies through if it leaves at its usual time.
Smooth most of the way, with occasional light bumps on descent. Barely moves your drink.
- Bumpiest stretch
- Light
- Flight time
- 14h 10m
- Distance
- 9,640 km
- Cruise altitude
- 37,000 ft
- Weather models
- 3 blended
- Model agreement
- High
- Aircraft
- Boeing 777
Bumpiness along the flight
Takeoff on the left, landing on the right. The higher the line, the bumpier the air the forecast expects at that moment.
Where, and why
The flight split into stretches: how bumpy each is forecast to be, and what causes it.
Cruise0m – 10h 57mSmooth
Nothing significant forecast here.
At cruise the air is thin and cold, and most of it is calm. The bumps up here come from the jet stream, a band of fast wind whose edges stir the air, or from waves set off by mountains far below. This forecast shows where those edges are.
Cruise10h 57m – 11h 48mLight
Jet-stream wind shear
Where fast air slides over slower air, usually at the edge of the jet stream, the boundary ripples like a flag. It's the most common kind of turbulence, and it's on the crew's charts before departure. When they meet it, they slow to a set turbulence speed and ride it out.
At cruise the air is thin and cold, and most of it is calm. The bumps up here come from the jet stream, a band of fast wind whose edges stir the air, or from waves set off by mountains far below. This forecast shows where those edges are.
Cruise11h 48m – 14h 10mSmooth
Nothing significant forecast here.
At cruise the air is thin and cold, and most of it is calm. The bumps up here come from the jet stream, a band of fast wind whose edges stir the air, or from waves set off by mountains far below. This forecast shows where those edges are.
Thunderstorms near the route
Between 1h 16m and 6h 34m into the flight the forecast has a few thunderstorms, some on the planned line itself.
The ride line can stay calm with storms nearby. It follows the planned track at cruise height, above most storm tops. Pilots don't fly through storms: the weather radar in the nose shows each one, and the rule is to stay at least 20 nautical miles (about 37 km) away. Usually that means a detour of a few minutes.
The closest of these is within the 20 nm the crew has to keep, so expect a small turn around it. The line on the map is the planned route; the real track will bend around the storm.
This forecast changes. FlyBud tells you when.
A new weather model run lands every few hours. Add CX253 in FlyBud and you get the full turbulence map along your route, a push when the forecast for your flight changes, live tracking and your flight on the lock screen.
Flight status
The latest CX253 flight on our records, as the airline last reported it.
Last update 12 days ago
Gate changes, delays and the baggage belt, pushed to your phone as they happen.
The aircraft
What CX253 is flown with, and how it handles bumpy air.
Boeing 777
- Type code
- B777
- Seats on this flight
- 294
Bigger and heavier aircraft are moved less by the same patch of air, and every airliner is designed for much stronger turbulence than it will meet.
The airline
Cathay Pacific
- Flying since
- 1946
- Alliance
- Oneworld
- Hubs
- Hong Kong
- Country
- Hong Kong
The route
Hong Kong (HKG) → London (LHR)
- Distance
- 9,640 km
- Flight time
- 14h 10m
- Usual departure
- 13:25 local
- Usual arrival
- 20:35 local
Recent CX253 flights
The forecast each flight carried, and how it ran.
| Date | Aircraft | Forecast | How it ran |
|---|---|---|---|
| Sat 24 Oct | B777 | Moderate | On time |
What each level feels like
- Smooth
- Calm air. Nothing to notice beyond the hum of the engines.
- Light
- Gentle ripples and the odd dip. Drinks stay put, and walking to the toilet is fine.
- Moderate
- Clear bumps. Drinks may slosh and the belt sign comes on. Uncomfortable, but the pilots stay in full control.
- Severe
- Strong jolts, and loose items can move. This is rare, and it's why the belt sign exists. Crews slow down and change altitude to get out of it.
How this forecast is made
The planned route is sampled from gate to gate at the altitude the aircraft flies, through 3 independent global weather models, and corrected with turbulence reports radioed in by pilots in the last few hours. Each new model run replaces the forecast; nothing here is a guess from the airline's history.
The independent weather models behind this forecast agree on this ride.
Planned route · timing and conditions may change.
Why turbulence isn't dangerous
Aircraft are designed for much worse.
Airliners are tested to loads well beyond anything turbulence produces. The wings are meant to flex, so seeing them move is normal.
Crews know where it is.
Your crew has forecasts like this one, live reports from other pilots and their own weather radar, and they change altitude to stay out of bumpy air.
Keep your belt on.
Almost all turbulence injuries happen to people who are standing or not buckled in. Seated with your belt on, turbulence is uncomfortable but not dangerous.
Questions about CX253
Will CX253 be bumpy?
For the flight on Sat 7 Nov: Smooth most of the way, with occasional light bumps on descent. Barely moves your drink. The forecast is replaced with every new weather model run, so check back closer to departure.
What plane flies CX253?
Recently CX253 has been flown with: B777. Airlines can swap the aircraft until shortly before departure.
How long is CX253?
About 14h 10m gate to gate from Hong Kong to London, a distance of about 9,640 km.
What time does CX253 leave?
CX253 usually departs Hong Kong at 13:25 local time and arrives in London at 20:35 local time. Times change; the app tracks the live schedule.
Is turbulence dangerous on CX253?
Turbulence is uncomfortable, not dangerous to the aircraft. Airliners are certified for loads far beyond anything turbulence produces, and crews plan around the bumpy patches with the same kind of forecast as this one. Injuries are almost always to people who were standing or unbuckled, so keep your seatbelt fastened whenever you're seated.
How accurate is this turbulence forecast?
It is a forecast, so it is best within a day or so of departure and improves with every model run. The bumpy patches it finds are usually in the right place, but their timing can shift by a few minutes and the crew may change altitude to avoid them, so the ride you get is often smoother than the forecast.
Fly CX253 knowing what's ahead
The turbulence forecast for your exact flight, live tracking, delay alerts and arrival weather. Built for people who'd rather know.