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Route turbulence forecast
Turbulence forecast for flights from Seattle Tacoma International Airport (SEA) to Washington Dulles International Airport (IAD).
Get a segment-by-segment turbulence forecast for any scheduled flight from SEA to IAD, with live wind and pilot reports.
Live status with real-time delays and cancellations.
Eastbound (generally tailwind-assisted) · Great-circle bearing 88°
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 Rocky Mountains, which can generate mountain-wave turbulence downwind when upper-level winds are strong. Flying eastbound, aircraft usually benefit from tailwinds near the jet core, which trims flight time — but the edges of the jet are where clear-air turbulence most often sits.
Transpacific routes are most turbulent in winter months when the polar jet is strong and positioned further south. Wind flowing over Rocky Mountains can generate mountain-wave turbulence that extends hundreds of kilometres downwind — most pronounced in winter when upper-level winds are strongest.
Most of the 3,702 km route sits in the mid latitude band with high jet-stream exposure. Historically that means occasional clear-air turbulence at cruise altitude is normal, especially in winter. Mountain-wave effects near the Rocky Mountains add short bumpy stretches when upper-level winds are strong.
Statistically, Late spring and early autumn sees the calmest conditions for this corridor. Within any season, morning departures see less convective (thunderstorm-driven) turbulence than afternoon flights.
Block time is usually around 4h 48m direct, cruising at approximately FL370 (37,000 ft). Actual duration varies with winds — tailwinds can shave 15–30 minutes, headwinds can add 30+ minutes on this eastbound sector.
We use live NOAA Aviation Weather Center pilot reports (PIREPs), SIGMETs and AIRMETs, layered with physics-based Ellrod and Richardson-number calculations 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 value.
Articles
Articles that unpack the factors driving turbulence on this type of route.
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 moreClear-air turbulence over the North Atlantic has increased 55% since 1979. Here's the atmospheric science behind the trend, what's projected through 2050, and what it means for passengers, airlines, and safety.
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.
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