AS16 is for the FSX, FSX:SE and Prepar3D v3 desktop flight sim platforms

Active Sky 2016 (AS16) represents the culmination of 16 years of weather simulation engine development! New In-Cloud Motion Effects, Weather Scenarios System, Airborne Weather Radar, P3D v3 Visibility Smoothing and Volumetric Fog Integration, Navigraph Data Integration, Re-designed Map-based Custom Weather Editing System, Universal Web Companion App, an Improved Mapping System and a High-Latitude Cloud Squeeze Fix are just a few of the new features to debut in this brand new version of Active Sky.

Beyond the many new features, AS16 also extends and improves all aspects of weather simulation and depiction, from data parsing, to synthesis, interpolation, depiction, performance, and everything in-between, your entire weather experience will be more realistic than ever before.

AS16 also incorporates full integration with Active Sky Cloud Art (ASCA), our brand new graphics add-on for both FSX and P3D.  ASCA includes cloud textures, sky textures, and brand new 3D cloud models to transform your skies, while also debuting a ground-breaking new feature when used in combination with AS16: Real-Time Dynamic Cloud and Sky Textures!  This enables realistic weather-influenced texture variation that reloads throughout your flight without needing to shut down and restart your simulator.  You can use any graphics add-on(s) with AS16, but dynamic texture reloads require the AS16+ASCA combination.

Now available is SP1 for AS16  which incorporates significant enhancements, adjustments, fixes and tweaks to further increase realism, immersion and functionality. Highlights include new P3D visibility improvements, cloud motion effect improvements, improved restricted visibility depiction, new jet-stream and wind-layer shear turbulence influence effects, interpolation improvements, generation depiction improvements, additional API functionality, P3D v3.4.18 support and much more.

SP1 upgrade is available absolutely free of charge to all existing AS16 users. Visit our downloads page to download right now!

Active Sky 2016 (AS16) is NOT compatible with P3D  v4.  It is only compatible with P3D v3.  For our P3D v4 product, please see here.  AS16 for P3D users receive a free “upgrade” to ASP4.  Other/previous product customers will be eligible for an upgrade discount when released.


Active Sky Products are offered via several authorized re-sellers.  Authorized re-sellers include: FSPS Store, SimMarket, Just Flight and  Notice:  Purchasing from an unauthorized re-seller may result in modified pirate software and/or malware and will result in that product/license being deactivated and unable to be used.  Please purchase only through the authorized re-sellers.

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*** Resellers may offer different base currency, policies and effective pricing.  Check with your reseller for details ***


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Additional Features
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Visibility Improvements, Effects Improvements, New API Features and More!

Redesigned P3D visibility depiction was overall a great improvement to debut in AS16, but many users had different needs and expectations, and asked us for enhancements in several key areas including elimination of excessive haze at the horizon, elimination of occasional sudden visibility shifts around 10,000ft, and better restricted visibility depiction, both surface and aloft, without harsh lines in certain scenarios. We’ve reworked the visibility depiction again, and significantly improve these areas (and several others) with SP1.  Cloud motion effect detection/synchronization and general speed sensation and particle effect placement was another area our users asked us to work on, and we have spent considerable time improving this for SP1.

Beyond the visibility and effects improvements, there are also new user options, improved turbulence effects, jet-stream and boundary-layer turbulence effects, general depiction and interpolation improvements, and hundreds of minor fixes and adjustments in effort to make AS16 even better.

Finally, many new API functions and capabilities have been added, enabling all kinds of developers to tightly integrate with Active Sky technology in all aspects including getting and setting weather, controlling weather modes and more.


In-Cloud Motion Effects

Feel the speed of motion while flying through clouds

 P3D Visibility Smoothing and Volumetric Fog Integration

Finally, smooth and realistic visibility depiction for P3D is here

XGauge WX + Radar

Enhanced weather gauge with included realistic airborne radar modeXGAUGE

Weather Scenarios System

Challenge yourself with several scenarios including a Microburst Encounter, Gusting Winds, Wake Turbulence, and more


High-Latitude Cloud Squeeze Fix

Fly high-latitude areas without stretched clouds



Map-Based Custom Weather Editing System

We’ve re-designed custom weather editing and provided a new easy map-based custom weather area manager and weather setting wizard


ASCA Integration for Real-Time Texture Dynamics

AS16 works with any texture/graphics add-ons (including default graphics), but when combined with ASCA, real-time texture dynamics and automatic wx-influenced selections are enabled

Dynamic Graph_Final

Web Companion App

Remotely view and control weather using any device on your local network with new webserver/browser technology

active sky weather image

New Map System

Vector Background Options and New Overlays


NAVIGRAPH Data Integration

Airports, Navaids and Fixes now provided by Navigraph!  A complimentary expired database is included with AS16, and regular AIRAC cycle updates are available with a Navigraph subscription



2 Versions: AS16 for FSX and AS16 for P3D

AS16 for FSX supports Flight Simulator X (Boxed) versions SP2 or Acceleration and FSX:Steam Edition

AS16 for P3D supports Prepar3D version 3.2.3 and later


Award-Winning Active Sky Weather Simulation Engine – Enhanced Further!

We’ve been enhancing and growing Active Sky since 2000, and this new version expands our weather engine even further than ever before

Enhanced Thunderstorm Effects

Thunderstorms are now very dangerous, as they are in the real world, and require avoidance, in most cases, to ensure safe and successful completion of your flights – Flying into heavy cells can result in loss of aircraft control and even airframe stress overload

Performance-Focused Design

We’ve taken the previous codebase for Active Sky and re-factored it, tuned it, and re-designed many core areas for increased performance and usability

User Interface Improvements

We’ve incorporated user feedback and made dozens and dozens of improvements throughout the entire UI

Hybrid Weather Depiction Technology

AS16 uses multiple integration and depiction methods to provide realistic, smooth and correct weather and ambient conditions at all times, while also providing full cloud position awareness to enable advanced cloud-synchronized radar, precipitation and air effects

High-Fidelity Data Resolution and Coverage

Active Sky 16 includes enhanced global gridded weather data, global sigmets and airmets, global surface data and global aloft data for much improved realism and coverage for all kinds of conditions in all areas without relying strictly on METAR reports

High-Fidelity Air Effects

Wake Turbulence, Microbursts, Downdrafts, Updrafts, Terrain-influenced Drafts, Thermals and more!

Smooth Transitions

Cloud formations, wind, temperature, visibility and every other aspect of your weather is smoothed, transitioned and interpolated for the ultimate in realism

Private Server Network

AS16 utilizes the high-performance and high-availability HiFi DataNet weather network with multiple servers in multiple regions around the world, providing high-resolution weather data and historical data archives for the past 2 years

Online Historical Data with Playback

Fly in weather at any date/time up to 2 years in the past and have weather update realistically throughout your flight according to hourly-archived conditions

Active Sky API

AS16 utilizes an extended version of the Active Sky API, allowing 3rd party developers to integrate and take advantage of advanced radar, icing, wind shear, weather data and weather controlling extensibility

Much More!

AS16’s full feature list is too numerous to list here, but we invite you to TRY AS16 FREE for yourself and experience all it has to offer!

While ASCA and AS16 work great together, they are also fully compatible (either alone or together) with any other graphics add-on and weather add-on. You have full flexibility to mix and match any aspect and selectable feature set within these add-ons.


Windows Vista or later

Microsoft Flight Simulator X with SP2 or Acceleration or FSX:Steam Edition (AS16 for FSX)

Prepar3D v3.2, v3.3 or v3.4 (AS16 for Prepar3D) – NOT COMPATIBLE WITH P3D v4

AS16 is offered in 2 different versions: AS16 for FSX and AS16 for P3D – Each requires a separate license

2GHZ processor or better

2GB RAM or better

1GB available hard drive space

Minimum monitor resolution to access all user interface features: 1024×768

Sound device (for sound and voice features)

Requires an online internet connection for normal usage.  Online activation is mandatory.  License is valid for one computer/installation only.  Moving software to another computer will deactivate the previous computer.  10 automatic reactivations are permitted.  Multiple-computer installations will require an individual AS16 license for each computer that it is installed on.


3.0GHZ Processor or better

4GB RAM or better

Broadband high-speed internet connection

1280×800 or better resolution



All screenshots on this page are unedited,  brought straight from the simulator, with only a frame border applied for presentation. What you see is what you get!



 Here is a comprehensive list of changes and additions in Service Pack 1!

AS16 for FSX / P3D Service Pack 1


– P3D Compatibility Updates for v3.4.14 and v3.4.18
– Added new warnings option for “prompt on exit”
– Added increased occasional light chop turbulence in clear air
– Added boundary/jet-aware aloft clear air turbulence influence
– Added new cloud sprite->radar echo randomization processes to cumulus clouds for better radar visuals and less patterns
– Improved cloud motion effect for increased apparent speed, better positioning and better detection
– Added new night-based lighted cloud motion effect when landing light is on
– Added new geographic influence capability with ASCA integration for latitude-based sky color influence
– Added additional Navigraph options for NDB
– Updated Audio Engine for better performance and compatibility
– Added new option “Use Navigraph data for VORs and NDBs” allowing user to disable navigraph data for VOR/NDB stations, utilizing legacy database and allowing user customization (i.e. for adding historical/fictional navaids) – default ON
– Added new option “Show connection lost messages” which will prevent pop-up messages (that may cause loss of simulator focus at critical times) and instead show these error connection messages in-sim when connected to sim and AS16 is not in focus – default ON
– Implemented better handling of stalled/error of ASCA installation during theme reload, so that AS16 weather will not stall (and an error message will be shown indicating ASCA error, while weather depiction continues)
– Updated documentation, Performance Considerations chapter, to mention CLOUD_SHADOW_TEXTURE_SIZE setting recommendation of 256 (vs 512) to improve performance
– Added new Warnings option for cloud density slider setting warning
– Attempted wake encounter filtering when flying helicopters, using ATC aircraft ID against known helicopter ICAO types (requires aircraft to use proper ICAO types, and not all add-on helicopters do)

 Visibility Improvements for P3D:

– Further redesign and improvement in visibility depiction and configuration
– Adjusted volumetric fog / surface visibility layer to be dynamic based on conditions – for better overall visuals in most cases
– Eliminated visibility-related flashing at certain altitudes
– Adjusted visibility layer selection processes to reduce vis changes when flying in variable mountainous terrain
– Adjusted visibility graduation to be exponential for more realistic depiction
– Various adjustments to improve/increase apparent visibility in appropriate conditions
– Various adjustments to decrease apparent haze near horizon in higher-visibility conditions
– Adjusted Automatic Upper Visibility Adjustment logic to bias towards higher visibility
– Added volumetric fog + overcast awareness and special depiction mode for more realistic experience
– Further volumetric fog smoothing adjustments
– Eliminated auto adjust upper visibility options when Volumetric Fog is enabled (now automatically adjusted for best results)
– Added volumetric fog smoothing delay when overflying temporary/occasional areas of reduced visibility, to prevent significant back and forth changes in such conditions
– Added detection, re-syntehsis and automatic refresh on user-initiated change of P3D volumetric fog option (no longer requires AS16 restart)
– Adjusted visibility depiction to remove 2nd visibility layer when Maximum Upper Visibility setting is 200 miles, which can improve performance
– Visibility depiction improvements to prevent depiction anomalies in low visibility especially in mountainous terrain
– Changed default Maximum Upper Visibility setting to 199sm (the maximum vis with 2 visibility layers)
– Further adjustments to apparent visibility graduation ceiling, providing quicker clearing of skies when climbing above surface level when volumetric fog is enabled


– Fixed lingering crash on sim exit issue
– Corrected ENFB data station location
– Fixed an issue with dynamic CDD reverting to 60 with a low cloud strain score
– Fixed an issue preventing SimConnect from reconnecting in a networked configuration when sim restarted
– Fixed a corrupt interpolation data message possible in conditions screen in some cases
– Fixed an issue with “Disable Winds Aloft” option not being respected
– Fixed issue related to flight plans with airports as intermediate waypoints
– Fixed rare ASConnect load issue + ambients error related to some Vista installations
– Adjusted installer update processes to not launch “delete saved data” routine in update packages, but only in original installation item, to attempt avoiding looping uninstall process
– Adjusted icing depiction to allow icing in precipitation when precipitating clouds themselves have no icing (i.e. freezing rain, inversion layers)
– Updated XGauge docs section (titles and organization)
– Small adjustments to reduce high altitude CU frequency (unless convective activity is present)
– Fixed gusting winds issue where gusts would not be depicted above a 1kt gust factor in some cases
– Added a filter for light chop above 40kft, to prevent excessive turbulence
– Added a filter for cirrus clouds to prevent unexpected “thin line” depiction when flying above in some cases
– Fixed issue with VOR showing as User waypoint when attempting to add a waypoint in Flight Plan screen

 API Improvements:

– Added new configurable location-based effects using userEffects.xml definitions for thermals, drafts, windshear and thermals
– Extended GetAtmosphere C++ API function
– Added GetAtmosphere HTTP function
– Added GetMetarInfoAt HTTP function
– Added Wx Mode get/set HTTP functions
– Added ability to set custom wx by passing xml definition directly through URL
– Added custom effects setting HTTP function
– Added GetCurrentConditions HTTP function
– Added GetClosestStationWeather HTTP function
– Added LoadFlightPlan HTTP function
– Added export of clientIPaddress and httpPort through dll API vars + updated API docs
– Updated API Documentation


Will PMDG 737/777, iFly 737, or other aircraft add-ons using ASN Radar API continue to work with AS16?

Yes!  The Active Sky API has been improved but remains fully backward-compatible with all current ASN integration techniques!

Do I have to use ASCA with AS16?

No, AS16 is compatible with all graphics including default graphics.  AS16 can be combined with ASCA for real-time dynamic texture reloads, but this feature is not required.  Feel free to use your favorite graphics add-ons with AS16 just as you have been able to with ASN!

Will I get AS16 for FSX and AS16 for P3D with a single license as before with ASN?

No, AS16 for FSX and AS16 for P3D are separately licensed, separately developed and separately maintained (with separate price points).


Feature Highlights
Additional Features
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Frequently Asked Questions