Loading...
Fetching the latest data.
Tokyo, Japan
NRT (Tokyo, Japan) sits at 35.76°N, 140.39°E, 141 ft elevation — coastal with the Japanese Alps nearby.
Major international gateway to Japan.
Computed from NRT's geography and climate
Tokyo sits squarely under the mid-latitude-latitude jet, north of which most long-haul corridors run. Clear-air turbulence (CAT) at cruise is the most common source of bumps on departures from here, especially during December–February when the jet is at its strongest. The Japanese Alps sit upwind of NRT on prevailing flow days, generating mountain-wave turbulence that can extend several hundred kilometres downwind at cruise level. The lee-wave risk is highest when December–February winds at FL300 cross the Japanese Alps at near-perpendicular angles. Warm-season convection (June–August) drives the dominant turbulence pattern from NRT — afternoon thunderstorm cells are routed around but their wake turbulence and gust fronts can still affect arrivals and departures. NRT's coastal position means departures often transit from the cool marine boundary layer into warmer continental air within minutes of takeoff — a brief but reliable bumpy transition on warm-season afternoons when the sea breeze is set up.
Standard Instrument Departures (SIDs) often route around terrain; on strong-wind days, low-level turbulence in the lee of the hills is common in the first few thousand feet.
Pacific jet stream significantly affects transpacific routes. Winter months see stronger jet stream activity. Typhoon season (July-October) can cause convective turbulence.
Winter (December–February) brings the strongest jet-stream activity — that's when long-haul departures most often log clear-air turbulence at cruise. Summer (June–August) is peak thunderstorm season — convective turbulence is the dominant warm-season risk. Mountain-wave activity near the Japanese Alps peaks in the cold season when upper-level winds blow hardest across the range.
Get a real-time turbulence forecast for any scheduled flight out of Narita International Airport, with live wind, jet-stream analysis and pilot reports.
Narita International Airport is best described as a jet-stream + mountain-wave corridor. Tokyo sits squarely under the mid-latitude-latitude jet, north of which most long-haul corridors run. Clear-air turbulence (CAT) at cruise is the most common source of bumps on departures from here, especially during December–February when the jet is at its strongest. The Japanese Alps sit upwind of NRT on prevailing flow days, generating mountain-wave turbulence that can extend several hundred kilometres downwind at cruise level. The lee-wave risk is highest when December–February winds at FL300 cross the Japanese Alps at near-perpendicular angles. Warm-season convection (June–August) drives the dominant turbulence pattern from NRT — afternoon thunderstorm cells are routed around but their wake turbulence and gust fronts can still affect arrivals and departures. NRT's coastal position means departures often transit from the cool marine boundary layer into warmer continental air within minutes of takeoff — a brief but reliable bumpy transition on warm-season afternoons when the sea breeze is set up.
Winter (December–February) brings the strongest jet-stream activity — that's when long-haul departures most often log clear-air turbulence at cruise. Summer (June–August) is peak thunderstorm season — convective turbulence is the dominant warm-season risk. Mountain-wave activity near the Japanese Alps peaks in the cold season when upper-level winds blow hardest across the range. Peak turbulence window: November–February (strong jet). Typically calmest: May–September.
Yes — the Japanese Alps lie close enough to generate mountain-wave turbulence on days with strong upper-level winds. These waves can propagate hundreds of kilometres downwind, so they sometimes affect cruise even after you've left the immediate area.
We combine live NOAA Aviation Weather Center data (PIREPs, SIGMETs, AIRMETs) with physics-based Ellrod and Richardson-number calculations derived from Open-Meteo pressure-level wind and temperature data. If a source is unavailable for a waypoint we show an em dash rather than invent a number.
Articles
Background reading on the factors that shape your flight.
Winter over the Atlantic, monsoon over Asia, summer over the US — turbulence has a calendar. Here's the month-by-month pattern for every major flight corridor, and the best months to book a smoother flight.
Read moreShort answer: almost certainly not. Here's the full engineering, historical, and statistical picture of how modern aircraft handle turbulence — including what the Singapore Airlines SQ321 incident really tells us.
Read moreUnderstanding Clear Air Turbulence - what causes it, where it occurs, and why it's the hardest type of turbulence to predict. Essential reading for frequent flyers.
Read more