Alaska Airlines SEA HNL AS821
Alaska Airlines
FLIGHT
AS821
SEA
Seattle–Tacoma International Airport
HNL
Daniel K Inouye International Airport
Altitude: 40,000ft (12.2km) Distance: 2,326 nm Duration: h m
ALTITUDE
40,000ft
DISTANCE
2,326 nm
DURATION
h m
Times and gates subject to change. Verify with airline.
Turbulence Comfort Along Route Comfort View
Comfort Score: Combines turbulence probability (GTG forecast) with intensity (ZTI analysis). High scores indicate both high probability AND high intensity turbulence.
Smooth
Light
Moderate
Severe
Flight Smoothness Score
8.8 /10
Smoothness
Smooth Flight
50%
Smooth
50%
Light
AI-Powered Flight Briefing
📊 8,500 data points analyzed HIGH Confidence
Your Flight

We analysed more than 8,500 data points along your route from Seattle–Tacoma International Airport, Seattle to Daniel K Inouye International Airport, Honolulu, Oahu.

Your Journey Beta

Your route takes you crossing the North Pacific Ocean – conditions there can sometimes cause light turbulence.

Smooth Flight

We're expecting smooth conditions throughout your flight. You can sit back and relax.

Takeoff

Takeoff should feel smooth, with calm conditions around the airport.

Winds Aloft

Winds at cruising altitude are about 41 knots. These winds may delay arrival by up to 12 minutes.

Landing

Landing should feel smooth with possible light bumps with typical approach conditions.

You're in Safe Hands

If you feel nervous at any point, remember that turbulence is expected, safe, and part of normal flying. The crew is monitoring everything, and the aircraft is built to handle far more than anything you will feel. Have a safe and calm flight.

Relaxation Exercises
ZeroTurb Index (ZTI): Powered by our proprietary turbulence prediction algorithm combining atmospheric Richardson Number, wind shear analysis, temperature gradients, and geomagnetic activity for precise, real-time forecasting. Learn more
Live data from ECMWF global forecast models • 12 atmospheric pressure levels analyzed • Updated every 6 hours
Flight Timeline 5h 31min
Maximum turbulence expected per segment
Takeoff
Smooth
0:30-0:58
Light
0:58-1:25
Light
1:25-1:52
Light
1:52-2:19
Light
2:19-2:46
Light
2:46-3:13
Light
3:13-3:40
Light
3:40-4:07
Light
4:07-4:34
Light
4:34-5:01
Light
Landing
Light
Smooth
Light
Moderate
Severe
Longer bars indicate higher turbulence intensity. Values shown are the maximum for each time segment.
Turbulence Metrics ZTI and EDR (scaled)
ZTI Scale
Smooth
<12
Light
12-30
Moderate
30-45
Severe
>45
EDR Scale
Smooth
<6
Light
6-24
Moderate
24-42
Severe
>42

Airport Weather
Departure
SEA
Forecast
4°C (Now)
Overcast • 9 kt • VFR — Clear conditions, no delays expected
Arrival
HNL
Forecast
21°C (Now)
Few • 11 kt • VFR — Clear conditions, no delays expected

Looking for more detailed analysis?

Data Sources & Our Approach
ZeroTurb's Custom Algorithm: We've developed a proprietary ZeroTurb Index (ZTI) algorithm that combines three meteorological indices weighted by their predictive accuracy. This gives you transparent, passenger-focused turbulence probability instead of vague categories.

This forecast integrates data from:

Disclaimer: This forecast is for informational purposes only. Always consult official aviation weather sources and follow ATC guidance.

How accurate are turbulence alerts? Alerts are based on updated forecast models and pilot reports, and can change as departure approaches.