Detail turbulence

ForeFlight introduces crowdsourced turbulence reports

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6 min read
Sentry Plus on window of Cessna

Sentry and Sentry Plus models include an AHRS that can be used to record turbulence.

Electronic flight bag apps like ForeFlight, when paired with portable weather receivers like Sentry, make it much easier for pilots to avoid in-flight weather hazards. That includes the big three threats (thunderstorms, in-flight icing, and low IFR conditions), but right after those critical concerns comes passenger comfort—and that usually means turbulence. Even if it’s not dangerous, constant bumps can ruin an otherwise pleasant flight. Now ForeFlight has found a creative way to give pilots more detailed and timely information.

Version 16.4 adds an optional Reported Turbulence layer on the Maps page, but it’s not your typical FAA weather forecast. Instead, it presents live, automated reports from other pilots who are flying with a Sentry. Using the built-in attitude sensors in these devices, ForeFlight automatically records G-load, then downloads anonymized data and uploads it when the iPad is connected to the internet. The result is essentially crowdsourced ride reports. This is a major breakthrough, but there are some important details to understand, so read on before you update the app.

Two major improvements

Graphical turbulence forecasts and pilot reports (PIREPs) are essential products for preflight planning, but ForeFlight’s novel approach offers two key benefits over traditional turbulence products.

1. There are a lot more reports. Because Sentry is automatically recording attitude data, pilots don’t have to remember to make a report and air traffic control doesn’t have to remember to send the report through the system. In fact, ForeFlight estimates their Reported Turbulence layer offers 50 times more turbulence reports than manual PIREPs. That can make a dramatic difference, especially for piston pilots who want to know about low altitude turbulence.

Here’s an example of PIREPs on a fairly calm afternoon—you’ll notice very few turbulence PIREPs below 10,000 feet:


And here is ForeFlight’s Reported Turbulence layer showing reports just at 4000 feet—a significant increase in data. You can see airplanes flying long cross-countries, as they tend to draw straight lines across the map.

Reported turbulence

2. The reports are objective. Turbulence is notoriously subjective: one pilot’s moderate is another pilot’s light. ForeFlight is trying to normalize those reports by using actual sensor data plus some sophisticated algorithms (the team behind this new product explained how they calculate it and suffice it to say, it’s complicated). Each report is presented as a color-coded dot on a map, from gray to red:

Turbulence levels

Like a METAR, you can tap on a dot for more information, including age, airplane type, and speed (an important factor in determining how applicable a report is for your airplane).

Detail turbulence

Testing it

That’s the theory; how does it work? In our limited testing so far, Reported Turbulence looks like a major addition to a pilot’s toolkit. In particular, it’s great for GA pilots flying unpressurized airplanes, since the majority of PIREPs usually come from airline pilots in the flight levels. We can think of at least a dozen trips over the last year where having some meaningful reports of turbulence—good or bad—would have helped us make a better preflight decision. That’s why the altitude slider on the right side of the Maps page is so important. Slide it up and down to view reports at different altitudes and evaluate different options.

Even better, use the Profile view, accessed from the FPL menu at the top of the page. This makes it much easier to visualize where the bumps are, both in terms of your route and your planned altitude.

Profile view

The other major benefit we’ve seen in testing is that you find many more reports of smooth rides. Often, pilots only submit a PIREP when they encounter turbulence. That’s understandable, but a negative report can be just as valuable, and Reported Turbulence shows a lot of gray dots. Note the screenshot above, which shows a smooth flight going over the Appalachian Mountains at 10,000 feet. That’s a major confidence boost for a pilot contemplating such a route with relatively strong westerly winds.

There are a few weak points, though. First, ForeFlight’s layer seems to overstate the prevalence of moderate and severe turbulence just a bit. The dots show the worst turbulence over a two-minute interval, not the average, so this is partially intentional—ForeFlight is offering a worst case—but in general we think it’s pessimistic. Here’s an example, with dozens of reports of moderate turbulence at 3,000 feet and below:


And yet the overall weather was great on this day: no clouds, relatively light winds (no gusts) and no significant weather of any kind. Sure, there were a few afternoon thermals but we found it to be a typical-to-good day for flying in a light airplane. Did it meet the technical definition of moderate? Maybe, but the turbulence picture above can make it seem worse than it is.


One thing is for sure, though: if you see no turbulence, you can be confident in that report. That matters.

Also remember that these turbulence reports can only make their way onto your iPad when the pilot flying with a Sentry connects to WiFi or LTE. That might be immediately for turbine airplanes equipped with in-flight WiFi, but if it’s after landing the delay could be significant. Still, ForeFlight says nearly half the turbulence reports are live within an hour.

That’s impressive but it means you need to watch the time stamps on these turbulence reports by tapping on relevant dots. ForeFlight will show data up to six hours ago, which is forever when it comes to turbulence. However, the app is smart in how it displays the reports: as you zoom out, the map declutters and shows newer dots at larger scales.

Old turbulence reports

How to get it

One other difference with this product compared to traditional radar and METAR layers is that not everyone will see it. You must have the right subscription before the Reported Turbulence layer will appear, and pilots who own a Sentry receive a $50 discount.

Turbulence layer

For hardware, you must register a Sentry or Sentry Plus to your ForeFlight account to get the discount. To do that, visit and click on your name to access account information. From there you can register your Sentry by typing in your device’s serial number.

Sentry registration

Then make sure you have the right subscription, as Reported Turbulence is available as two subscription add-ons. Low covers altitudes up to 14,000 feet and is included with Pro Plus and Performance Plus subscriptions ($50/year but with a $50 discount), so if you register your Sentry there is no fee. For pilots of turbocharged and turbine airplanes, you’ll want to add the All package, which includes altitudes into the flight levels and costs $50/year after the discount. If you don’t fly with a Sentry or Sentry Plus but have a Pro or Performance subscription, you can add Reported Turbulence at for $50/year or $100/year. Also note that you must be flying with an active ADS-B Out transponder on your airplane, but this new feature does not require a Sentry firmware update.

ForeFlight version 16.4 also adds some other new features, including: lowest tilt radar as a map layer, a new landing factor selector option in runway analysis, and a printable TOLD card. More details from ForeFlight.

15 replies
  1. Adam
    Adam says:

    Ok, this is super cool. As lower time pilot trying to get comfortable flying in various conditions VFR this should be super helpful, especially when planning on taking the family etc. Smooth rides are ideal!

  2. Jim B
    Jim B says:

    The article says Reported Turbulence capability is included with Pro Plus and Performance Plus levels. What about the Military Flight Bag Performance package? Thousands of Civil Air Patrol pilots have that package as a member benefit. Is there a cost to add Reported Turbulence to a Military FBP packace?

  3. Ron McCormick
    Ron McCormick says:

    With the new update that Sentry will allow you to connect to cell data when Sentry wifi is connected to phone will this turblance data be real time as long as you have a cell signal?

    • John Zimmerman
      John Zimmerman says:

      That’s right, although obviously you won’t always have a cell connection in flight. It depends very much on where you’re flying and how high.

  4. Norm Worthington
    Norm Worthington says:

    I entered my Sentry serial number and Foreflight accepted it. I have Performance Plus. But, the option doesn’t show in Foreflight. All I see are the two Turbulence (US and Global). Haven’t been flying yet, but I did connect my Sentry to the iPad for a few minutes and the iPad is connected to WiFi. Is there some secret handshake required?

    • John Zimmerman
      John Zimmerman says:

      First, note that this layer only appears when using WiFi, so you won’t see it in flight. Second, try shutting down the app and restarting it (or even restarting your iPad). That may make it show up.

    • C. Friday
      C. Friday says:

      Same problem here. Registered my sentry, have a Pro Plus subscription, have restarted the app (on both my iPads), and have even tried logging out of ForeFlight and logging back in on one of them. Still no ‘Reported Turbulence’ layer. Anyone have any ideas?

  5. Lewis Lowe
    Lewis Lowe says:

    Seems a little restrictive. We have a multi owner plane, which has a sentry, but only one of the pilots will get the reports. We all use it the device, but only one of us will be able to send and receive the reports without paying more.
    This seems both restrictive for them (we could be sending them data) and restrictive for us (only one of us will receive the info, even though all of us paid for the sentry.

  6. Paul
    Paul says:

    Working through the logic. I don’t have a Sentry, but otherwise a full up-to-date Garmin retrofit panel. I should receive the turbulence reports if I pay the extra $50 on my already top-tier Foreflight subscription if I understand it accurately. But will obtaining turbulence reports in that manner actually contribute to the crowd-sourcing effort? Or does that only occur with using of the Sentry Plus?

    • John Zimmerman
      John Zimmerman says:

      That’s right – you can pay $50 and get the reported turbulence layer. You won’t be contributing reports unless you fly with a Sentry or Sentry Plus.

  7. Kent
    Kent says:

    We have a similar service in the airline world that is absolutely incredible. I’m so excited to be able to use it in GA flying as the airline version only works above 10,000.’


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