How long is flight AS3?

The SEA to JFK route is the basis for the schedule. View the full route forecast and typical duration on the Turbcast route page.

Flight AS3

AS3 Turbulence ForecastAlaska Airlines · SEA → JFK

About flight AS3

Airline: Alaska Airlines (AS)
Route: SEA → JFK
Typical Aircraft: B739
Distance: 3,887 km
Duration: 5h 01m
Cruise Altitude: FL370

See today’s turbulence forecast

Alaska Airlines AS3 flies the jet-stream + mountain-wave corridor from Seattle to New York. Conditions change hour to hour - view the live forecast for your departure date.

View live forecast

Check AS3 on a specific date

Turbulence on the SEA → JFK route

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.

Calmest season: Late spring to early autumn (May-September). This corridor is most turbulent in the northern winter (Nov-Mar), when the jet stream is strongest and sits closer to the route. Wind flowing over the Rocky Mountains can generate mountain-wave turbulence that extends hundreds of kilometres downwind - most pronounced in the northern winter (Nov-Mar), when upper-level winds are strongest.

Full SEA to JFK route guide

Frequently asked questions

Is AS3 usually a bumpy flight?

Alaska Airlines AS3 operates between SEA and JFK. Whether it’s bumpy depends on the day’s weather - Turbcast pulls live NOAA aviation-grade data so you can check the actual forecast for your departure date rather than relying on averages.

What aircraft does AS3 use?

AS3 is typically operated by the B739. Aircraft swaps happen - confirm with your booking before flying.

How long is the SEA to JFK flight?

Approximately 5h 01m direct, covering 3,887 km at a typical cruise of FL370.

When does AS3 have the smoothest weather?

Historically calmest during Late spring to early autumn (May-September). Forecast accuracy improves as you get closer to departure - within 48 hours the NOAA WAFS model is at peak skill.