About Turbcast
What is Turbcast?
Turbcast is a turbulence forecast tool designed for curious or nervous flyers. It provides detailed turbulence predictions for your route, free, and if you like it will watch your flight for you until takeoff so you can stop checking. Forecasts use NOAA’s GTG 4.0 on US routes and physics-based modelling from live upper-air data elsewhere, with live pilot reports from NOAA’s Aviation Weather Center layered on top.
How it works
1. Enter Your Flight Details
Provide your departure and arrival airports, along with your departure time.
2. We Calculate Your Route
Our system determines the most likely flight path using Great Circle calculations.
3. Weather Data Analysis
For US flights we sample NOAA’s operational GTG 4.0 turbulence model along your route; worldwide we run physics-based calculations from live upper-air data. Then we layer official advisories and pilot reports (SIGMETs, AIRMETs, PIREPs) from NOAA’s Aviation Weather Center on top.
4. Aircraft-Specific Forecast
Turbulence is experienced differently based on aircraft size. We adjust predictions for your aircraft type.
The forecast model
- US flights: built on NOAA’s Graphical Turbulence Guidance (GTG 4.0), the operational turbulence forecast system used across US aviation, which went live in March 2026 and verifies at around 0.85 AUC against aircraft turbulence measurements. Turbcast samples and presents this guidance along your route; it is not an official NOAA product. The GTG family is actively developed: in July 2026 NOAA added the GTG Nowcast, a 15-minute analysis that blends the forecast with live aircraft measurements and pilot reports.
- Everywhere else: a physics-based engine (Ellrod turbulence index + Richardson-number stability) computed from Open-Meteo upper-air data, sampled at your flight’s cruise altitude.
- Live advisories & pilot reports: SIGMETs, AIRMETs, G-AIRMETs and real-time PIREPs from NOAA’s Aviation Weather Center, layered on top of the model along your exact track.
- Flight schedules: AirLabs.
Turbcast is independent and is not affiliated with or endorsed by NOAA or the National Weather Service. NOAA data is used under its public-domain terms.
How we prove it
A forecast is only worth what it can be checked against. After every flight, we match our final briefing to the pilot reports filed along that route and grade ourselves, including the misses. We’d rather brief a bump that doesn’t happen than miss one, and the record shows which it was.
That same record is how the forecast keeps improving, and it’s published on the accuracy page, refreshed hourly with its sample sizes: measured accuracy on our forecasts, not a model’s headline number borrowed as our own.
Understanding turbulence levels
Bumpy ≠ unsafe: even ‘severe’ turbulence is well within what every commercial aircraft is built and tested for.
Important disclaimer
Turbulence forecasts are for informational purposes only and should not replace official airline guidance or pilot judgment. Weather conditions can change rapidly. Always follow the instructions of your flight crew and keep your seatbelt fastened when seated.
Who builds Turbcast
Turbcast is built and run by Leon Davies, an independent software developer. He started it in 2024 because he could not easily check what turbulence to expect before a flight, and wanted a forecast built on the same NOAA turbulence data pilots and dispatchers use, wherever it is available. Paid forecasts are checked against pilot reports where reports exist, and the results are published on the accuracy page.
Get in touch
Questions, feedback, or a request? Email info@turbcast.com.