A Closer Look at Global Icing, Turbulence, and Surface Analysis Map Layers

Available with ForeFlight Mobile 9.4, five new weather layers bring global Icing, Turbulence and surface pressure data to the map, with detailed Surface Analysis available to much of North America. These weather products significantly enhance local and global flight planning and your weather decision-making abilities. The new layers are available for customers with Pro Plus, Performance Plus, Business Performance, and MFB Performance subscription plans, on mobile and on the web. In addition, the recently introduced time slider provides frame-by-frame control over animation of the new weather layers. Let’s dive into the details!

Layer Animation Time Slider

The animation Time Slider tool provides better control over weather layer animation, as well as more clarity on the age of the weather product you are viewing. The slider automatically displays when you select any Radar, Satellite, Icing, or Turbulence layer.

Weather Layer Time Slider

In addition to the familiar play/pause button, the Time Slider allows frame-by-frame control over the animation. The slider’s position on the time scale indicates the valid time for the currently displayed weather graphic. Tapping to the right of the slider head advances the layer by one time step, while tapping to the left of the slider head retreats the layer by one time step. Alternatively, tap-hold and move the slider head left and right to manually control animation speed and enable back and forth (rocking) animation, a useful capability when analyzing local storm cell changes on radar.

The time scale changes as appropriate for each weather product displayed. Forecast-based weather layers, such as the Icing and Turbulence layers, use a white vertical bar to indicate the present time, splitting the time slider into two parts: forecasts that are valid for the past (gray line) and for the future (white line).

Products that indicate past information only, such as the radar and satellite layers, are presented with a gray time scale with the product age, relative to the current time, displayed with each frame. The absolute time is displayed in a callout with each frame as you manually scrub left or right, as well as to the left of the time scale.

Providing full manual control over the weather layer animation and easily reading relative age and absolute time for each weather product frame provides better insight to how the weather is trending.

Surface Analysis

The Surface Analysis layer adds a global surface pressure overlay, displaying isobar lines and associated pressure values in millibars. For much of North America, the isobar lines are complemented with depictions of surface fronts, troughs, and high/low pressure center markers. Besides displaying the current surface analysis, the forecasted surface analysis can be viewed for up to two days into the future using the Time Slider.

The Surface Analysis product and its forecast is a collaboration between multiple weather centers and is primarily based on the National Weather Service Global Forecast System (GFS) and the North American Mesoscale (NAM) models, with additional guidance from the European ECMWF and the United Kingdom’s UKMET models. Surface features (fronts, troughs, pressure centers) are analyzed manually by a NWS meteorologist, and are therefore only available for the North America region.

Surface Analysis features follow the standard depiction convention as outlined in the table below:

View global isobars and more detailed weather features for the U.S.


Icing severity data for the United States has been available in the ForeFlight Mobile Imagery view since 2015. Now, icing severity is available as a dynamic weather layer in the Maps view in ForeFlight Mobile and on the web. And not just for the US, but for the entire world.

You will now see two icing products in the Maps view layer selector: Icing (US) and Icing (Global). Both serve the same purpose, but are based on different weather models.

For the US coverage, the Forecast Icing Product (FIP) is a Numerical Weather Prediction model that employs a 20km grid in the horizontal and a 1000 ft grid in the vertical (from 3000’ to FL450) to calculate icing severity and the potential for SLD (supercooled large droplets). The FIP model is run hourly and forecasts are available out to 18 hours.

For a fast analysis of conditions at each altitude, you can quickly scrub between altitudes using the Altitude Slider in the lower right corner of the Maps view. The Altitude Slider is also available on the Turbulence layer.

Altitude Slider

Altitude Slider

Please note that SLD threat is currently only available to customers flying with the SiriusXM SXAR1 aviation receiver and who are subscribed to the SiriusXM Pilot for ForeFlight plan. SLD threats are depicted with red squares.

The Global Icing product is based on the Global Forecast System (GFS) weather model with a coarser horizontal and vertical grid and is run four times per day (every 6 hours). Global Icing forecasts in ForeFlight are available out to 24 hours.

Because of the coarser grid, as well as the less-frequent model runs of the GFS, it’s worth comparing the two icing depictions side-by-side. The difference in horizontal resolution and model update frequency between the US icing layer (left) and the global icing layer (right) is evident. When operating within the limits of the US icing model coverage area, the US icing layer should be referenced instead of the global layer to take advantage of its frequent updates and finer horizontal and vertical grid resolution.

Regardless of whether you have US or global icing selected, each layer uses the same color scale to depict conditions of no icing, light, moderate and heavy icing, as shown in the legend below:

Icing intensity is based on how long it would take for ice to build up on an airfoil

It’s important to note that the icing severity is roughly based on the accretion rate of ice on an airplane. The severity levels are defined by how long it would take for ¼ inch (65mm) of ice to build up on an airfoil. Time ranges are given for each level because the build-up rate depends on variables like airfoil properties, airspeed, and atmospheric conditions.

Since the icing forecasts are produced with no human modifications, they are intended for flight planning purposes only and should always be used in combination with AIRMETs, SIGMETs and PIREPs.


Similar to the Icing map layer, there are two new Turbulence map layers, one for the United States and the other for Global coverage.

The US turbulence product is based on the Graphical Turbulence Guidance (GTG). The GTG and the associated Eddy Dissipation Rate (EDR) data scale used by GTG were both covered in detail in a previous ForeFlight article. It’s worth re-reading that post to brush up on the turbulence product, especially how the relationship between EDR and in-flight turbulence intensity changes based on aircraft weight. The information in that article applies equally to the US and global turbulence layers.

The US turbulence layer data are still based on GTG-3 with an available lead time of up to 18 hours. This layer displays the maximum EDR of clear air turbulence (CAT) and mountain wave turbulence (MWT). It is not intended to predict convection and thunderstorm turbulence sources, but may provide some guidance if the storm event is widespread. Furthermore, the graphics represent a snapshot at that time and not a forecast for a time range. Finally, it is important to realize that turbulence is a dynamic event and rapidly changing conditions may not be accurately reflected.

The global turbulence layer displays EDR derived from the GFS forecast model using a proprietary algorithm. This layer differs from the US GTG-3 derived layer in that the global turbulence data only forecasts CAT and not MWT. The forecast lead time can be up to 24 hours. The same reduced horizontal and vertical resolutions discussed previously in the global icing section apply to the global turbulence layer. Also, since the global turbulence layer uses GFS model data, the same reduced model run rate limitation applies (every 6 hours for GFS versus hourly for GTG-3), resulting in the US turbulence layer being updated more frequently. For all of these reasons, it’s important to use the US turbulence layer when operating within its coverage area.

Since the layer’s EDR scale is aircraft dependent, it is important to review the scale applicable to your aircraft category (the article linked above contains scales for light, medium, and heavy aircraft classes). The following color scheme is used in the turbulence map layer:

These new weather layers are an exciting and useful feature addition for our US and worldwide customers. Keep in mind that there is no human involvement in creating the turbulence and icing products and the information should be supplemented as much as possible with SIGMETs, AIRMETs, and PIREPs to understand the full weather picture.

ForeFlight 8.2.3 Now Available on the App Store

ForeFlight version 8.2.3 corrects an issue with tail number checking that blocked filing with aircraft profiles set up using call signs rather than N-numbers. As always, we’re on frequency at team@foreflight.com if you experience any issues with the update.

ForeFlight 8.2 includes more data for Aeronautical Maps, new in-flight alerts that keep you aware on the ground and in the air, Logbook enhancements with improved currency tracking, Garmin Flight Stream 510 connectivity, and more. Click here to explore all the new features in 8.2.

File, Brief, Manage Aircraft Profiles With ForeFlight On The Web

In conjunction with ForeFlight 8, ForeFlight on the web features a number of updates that are now available for ForeFlight subscribers, including the ability to file flight plans, generate weather briefings, and manage aircraft profiles. You can also access and plan flights with our new global Aeronautical Maps. Log in to ForeFlight anytime using your ForeFlight Mobile credentials and access ForeFlight’s powerful flight planning from your desktop computer.

ForeFlight on the web

ForeFlight’s powerful flight planning capabilities are available on your desktop computer.

Route Editor, NavLog, & Route Advisor

Familiar Route Editor and Navlog views make it easy to build and edit a route using text input or rubber band planning. ForeFlight’s auto-complete search engine returns results as fast as you type based on waypoints, navaids, airport names, routes, and city names. Just like on ForeFlight Mobile, Route Advisor™ allows you to simply enter departure and destination identifiers into the Route Editor, then select from available route suggestions including airway, recently cleared ATC routes, preferred routes, or TEC routes.

ForeFlight web planner route advisor

Route Advisor helps you select from available route suggestions.

You will also see a new Aircraft tab on the left-hand side; here you can create and edit aircraft profiles. When you add performance data, the Navlog computes your route time and fuel burn, just like in the mobile app. The best part is that any aircraft profile changes you make on the web are automatically synced to your mobile devices.

In addition, the new global Aeronautical Maps look stunning on a desktop browser and include many of the same benefits as the mobile app, like dynamic decluttering, customizable information, light and dark themes, and Smart Airway Labels.

File & Brief Anywhere, Anytime

All of the same file and brief features you enjoy on ForeFlight Mobile are available via the web. You can amend and cancel IFR plans and activate and close VFR plans – and it’s all instantly synced to your iPad and iPhone. In the Aircraft view, you can add ICAO equipment and performance codes, and ForeFlight pre-populates your flight plan form with this information.

ForeFlight on the web graphical briefing

Generate ForeFlight’s Graphical Briefing right from your desktop computer.

ForeFlight’s Graphical Briefing can be generated on the web. Graphical Briefing transforms the standard text briefing information and delivers it in a visually elegant design for better readability – and it looks amazing in the full desktop view.

Check out this how-to video to learn more about Graphical Briefing:

Logbook On The Web

In addition to experience reports and the 8710 report, student pilots will enjoy keeping tabs on accumulated flight time towards their PPL or Instrument Rating using the new Progress Reports. These reports use data from your logbook entries to display a checklist of requirements needed for each, checking off each item as you complete it.

Logbook progress tracking report

ForeFlight Logbook Progress Reports help student pilots keep an eye on the prize.

ForeFlight on the web gives you more flexibility to plan and file when and where it is convenient. You can log in to ForeFlight anytime using your ForeFlight Mobile credentials. Access to Logbook features and the new Aeronautical Maps requires a Basic Plus or Pro Plus subscription plan. If you need to make changes to your subscription, you can do that on the web, too!

Expanded Airport Information in ForeFlight Web

We’ve recently added some new features to ForeFlight Web that enhance its usefulness for flight planning. The airport popup now closely mirrors the airport popup in the ForeFlight Mobile Maps view, including tabs along the bottom for general airport information, the current METAR, forecast products, and winds aloft.

Tap on a weather marker to access diverse information about an airport

Use the buttons along the bottom of the popup to view information about an airport, forecasts, and winds aloft.

From the Info tab you can find lists of frequencies, runway information (including wind components), and links to taxi charts and procedure plates that can be viewed directly in your browser. Links to outside resources like Google Maps and flight tracking through FlightAware are also available. The forecast tab includes TAFs, MOS, and recent area forecast discussions. All this information can be accessed simply by clicking on a weather overlay marker for an airport, or by searching for that airport in the Search bar.

The airport popup also includes an Add to Route button for easy “click planning”. With departure and destination points entered into your Navlog, you can then click on the route line to rubber-band it to intermediate waypoints and airports, just like touch planning in the ForeFlight app.

Click and drag your route line to add intermediate airports and waypoints

Intermediate waypoints can be added to your route just like in the app – drag your route line to the desired location, then drop it and select an item from the list.

After building your route on ForeFlight web, it automatically syncs to the app on your iPad and iPhone. You can find the route in ForeFlight Mobile in the Recent routes list, or in Favorites if you saved the route.

New Canadian and International NOTAMs Available in ForeFlight

ForeFlight customers now have access to a wealth of new international NOTAMs in the app. In particular, all Canadian NOTAMs available on the NavCanada website are now available in ForeFlight, saving our Canadian and cross-border customers valuable flight planning time.

Canadian NOTAMs now included all NOTAMs provided listed NavCanada's website

Most international airports now include NOTAMs for their FIR (Flight Information Region), which can be found under the ARTCC NOTAMs tab, as well as additional airport, obstacle, and TFR NOTAMs. The rate at which NOTAMs update in ForeFlight is also faster.

New NOTAMs are also available for many international airports

Although the number of NOTAMs available in ForeFlight has expanded greatly, it is not exhaustive, so be sure to check other sources for relevant NOTAMs when planning a flight outside the US.

Winds Aloft Forecasts in Graphical Briefing

The ForeFlight Graphical Briefing has a new section under the Forecasts heading: Winds Aloft. This section was added to provide pilots with information about the forecasted winds aloft along their route of flight, an important component of any preflight weather briefing.

Winds aloft forecasts along your route are organized in tables

The section includes forecasts for winds at 6 hour, 12 hour, and 24 hour periods, each contained in its own neatly organized table showing weather stations IDs along your route on the left, and altitudes along the top. Forecasts are provided for altitudes ranging from 3,000 to 53,000 feet, and a toggle switch at the top of the page allows you to restrict the altitudes shown to only those within 4,000 feet of your filed altitude, giving you quick access to the most relevant forecasts for your particular flight. In addition, the column showing winds aloft at your filed altitude is highlighted blue in each table.

You can enable ForeFlight Graphical Briefing at any time by navigating to More > Settings, scrolling down the File & Brief section, and tapping ForeFlight Briefing so the slider turns blue.

FAA to Begin Decommissioning VORs This Year

As part of the NextGen initiative to adopt a Performance Based Navigation (PBN) airway structure supported by GPS, the FAA is moving forward with plans to decommission approximately 30% of currently operating domestic VORs over the next 10 years. The VORs left behind will constitute a minimum operational network, intended to support conventional navigation in the event of a GPS outage, while not tying up resources maintaining unnecessary and underused VORs. The decommission process will take place in two phases, with the first phase lasting from 2016 to 2020, and the second phase lasting from 2021 to 2025.

Although the FAA has not released specific dates for when each VOR will be decommissioned, they have provided a list of the first 35 VORs that have been approved for decommissioning, and in what phase of the project each will be removed.

The removal of these VORs will have a large effect on the domestic airway structure and instrument procedures at many airports, and these changes will be reflected in the charts and data available in ForeFlight. Therefore we will continue to track this process and update you when specific dates are announced for each VOR.

New SIDs Published for KATL

The FAA recently approved a set of new departure procedures for KATL, and we included these in ForeFlight’s most recent data cycle update. The new SIDs are designed to make use of existing Performance-Based Navigation (PBN) technology, and will fully replace 16 of the current SIDs later this year. For now, however, these new SIDs are only to be assigned by ATC; flights out of Atlanta should continue to be filed with the current SIDs until the implementation is completed. A NOTAM to this effect has been published for KATL.

The new SIDs will fully replace the current ones later this year

In addition to these replacement SIDs, a new WIGLE1 SID was published for use during special events, and is also ATC assigned only.

A flight plan using one of the new SIDs may be accepted by ForeFlight, but will likely be rejected once it reaches the ATC computer, and even if accepted, will only cause coordination problems for both ATC and the pilot, so be sure to review the NOTAM before filing so you don’t accidentally use the wrong SID and have your clearance rejected. Of course, if ATC assigns you one of the new SIDs, you can use ForeFlight’s Procedure Advisor to load the route information onto the Maps view.

FAA Releases Advisory Ahead of Super Bowl 50

In preparation for the large amount of air traffic expected around San Francisco before and after Super Bowl 50 this Sunday, the FAA has released a set of guidelines for aircraft operating in the area. These include a requirement that pilots obtain ramp reservations at numerous nearby airports, as well as restrictions on what routes can be filed to or from those airports.

The notice from the FAA can be found in Documents > Catalog > FAA

For your convenience, the latest data release includes a document detailing these guidelines, which can be found in the FAA section of the ForeFlight Documents Catalog. The document outlines special traffic management procedures, and guidance on the NOTAMs and TFRs that will be in place prior to the event. This information can also be found online at the FAA’s website. We encourage any pilots who plan to fly in or out of Northern California over the next week to review this information before planning a flight.

How to Comply with Part 135 Air Ambulance Obstacle Requirement Using ForeFlight

You may be familiar with some of the regulations governing how FAA Part 135 aircraft operators prepare for and conduct flights, but did you know that helicopter air ambulance operators have a number of special rules all to themselves under Part 135? One of these requires the pilot of any VFR flight to identify and document the highest obstacle along the planned route (§135.615). This ensures that the pilot briefs this potential hazard and determines the minimum safe altitude for the flight.

While a good safety measure to prevent collisions, the requirement has been a pain point for some operators as the somewhat vague guidance to “identify and document” is left open to interpretation. Not to mention that some methods of complying with the requirement could take up a good chunk of a pilot’s preflight preparation time, which is at a premium with air ambulance operations.

Fortunately for air ambulance operators using ForeFlight, there is a fast and easy method of complying with the highest obstacle requirement in the app itself. This method employs ForeFlight’s Profile view (available with Pro and Pro Plus subscriptions).

Viewing obstacles along your route using Profile view

Start by entering departure and destination points in the Route Editor, then tap Profile to view the vertical cross-section of the planned route.

Terrain and obstacles are dynamically highlighted based on relative height to your selected altitude. Tap and hold anywhere in the Profile window (other than directly under the altitude box) and a vertical dotted line and box will appear showing that point’s altitude in MSL, the clearance in feet between the point and your planned altitude, and the distance of that point from your departure point. Dragging your finger right or left shows this information for any point along your route. The selected point is also displayed on the “top-down” view of your route below, revealing where the point is along your route.

Use Profile view to measure and document the highest obstacle along your route.

The profile window also allows for pinch-zooming and dragging so you can unclutter nearby obstacles. You can change the total width of the corridor shown in Profile by tapping the button at the bottom-right of the window and tapping “Corridor Width” at the bottom of the popup.

Using Profile view allows the highest obstacle along a route to be easily identified. As for “documenting” it, simply place the dotted line on the highest point and take a screenshot by pressing the iPad’s home and lock buttons at the same. The screenshot can then be accessed and shared from the iPad’s Photos app, or from a cloud storage app like Dropbox.

A number of air ambulance operators using ForeFlight have shared with us how this feature helps them comply with the highest obstacle requirement. We hope this helps you, too.