SiriusXM
vs. ADS-B/FIS-B Weather
SiriusXM Aviation Weather is a satellite delivered service and is available at any altitude, including when parked on the ramp and during taxi.
ADS-B/FIS-B is a ground-based weather service. Its availability varies based on your altitude and location in the U.S. and is only available on the ground in the immediate vicinity of certain airports.
What does this mean for you?
At most GA airports the ADS-B/FIS-B broadcast can’t be received until well above the traffic pattern. This could be compounded further if storms cells are developing nearby. For example, if you’re in a Cessna 172 going 90 knots, you could fly nearly seven minutes and 10 miles before you could make a decision based on ADS-B weather. To see SiriusXM's coverage map, click here.
SiriusXM Aviation Weather is a satellite delivered service with no line-of-sight restrictions.
ADS-B/FIS-B has line-of-sight restrictions.
What does this mean for you?
ADS-B is a ground-based network and has line-of-sight restrictions, so as you’re flying in areas with changing terrain there may be interruptions in critical weather information needed to make the best weather decisions possible. This is particularly noticeable near mountainous areas or valleys – and you won’t have any warning from the system when the data will be unavailable or when it will resume.
SiriusXM Aviation Weather has consistent coast-to-coast high-resolution Composite Radar (2km res) updating every 2.5 minutes.
ADS-B/FIS-B’s Composite Radar availability depends on what altitude you are flying at and whether you are viewing Regional Radar (2.5km res) updating every 5 minutes or CONUS (10km res) updating every 15 minutes.
What does this mean for you?
If you are using ADS-B, you may not have important storm information at lower altitudes and you will have to wait until you're at a higher altitude for an update. SiriusXM has consistent resolution and faster updating radar from wheels up to wheels down across the country.
SiriusXM has Cloud-to-Cloud and Cloud-to-Ground Lightning updating every 2.5 minutes.
ADS-B/FIS-B only has Cloud-to-Ground Lightning, updating every 5 minutes.
What does this mean for you?
Lightning is an important signpost that a particular area of weather contains severe or extreme convective turbulence. In the initial phase of a developing thunderstorm, it is common for a cell to consist of mainly Cloud-to-Cloud Lightning. Armed with this information and SiriusXM’s twice-as-fast refresh rate, you can make decisions sooner to minimize your exposure to an area with dangerous convection.
SiriusXM Aviation Weather has consistent coast-to-coast high-resolution Base Reflectivity Radar updating every 5 minutes.
ADS-B/FIS-B does not offer base reflectivity radar.
What does this mean for you?
The Base Reflectivity Radar from the lowest tilt lets you know what precipitation is coming out of the bottom of the storm cell and is especially beneficial if you are flying under 10,000 ft. The lowest tilt more closely matches what you are seeing outside of the cockpit.
SiriusXM Aviation Weather provides Storm Tracks and Echo Top heights to allow you to monitor the speed and direction of the most significant areas of weather.
ADS-B/FIS-B does not offer Storm Tracks or Echo Top heights.
What does this mean for you?
Knowing the height as well as the speed and direction of thunderstorms provides you with guidance so you know where the most significant storms will be relative to your route. This allows you to strategically maneuver around dangerous weather at a safe distance. With ADS-B/FIS-B you are left to estimate the movement of significant cells.
Every SiriusXM Aviation Weather product, including METARs and TAFs, are available from takeoff to landing.
ADS-B/FIS-B weather information is limited based on altitude and location.
What does this mean for you?
If you are flying with SiriusXM Aviation Weather you can receive important weather information whenever you request it. If you are flying with ADS-B you will need to wait until you’re at the right altitude and distance to request and receive the information.
See page 25 of the FAA Advisory Circular to learn more.
SiriusXM Aviation Weather provides actual Cloud Tops that show the highest cloud top based on infrared satellite data.
ADS-B/FIS-B provides forecasted Cloud Tops from a numerical weather prediction model.
What does this mean for you?
Because SiriusXM Cloud Tops are based on observational data, ADS-B/FIS-B forecasted data will never be as accurate, especially for convective cloud tops.
SiriusXM plans start as low as $29.99 per month, with the option to suspend for up to 6 months, once per year, at no additional cost.
ADS-B/FIS-B is free, but comes with many significant limitations.
What does this mean for you?
For as little as $180 for six months, you can fly from takeoff to landing with consistent, reliable weather. You can also add SiriusXM radio at a discount.
