Garmin GTN 650Xi Series Pilot's Manual page 323

SIRIUSXM NEXRAD
SiriusXM offers NEXRAD radar imagery from CONUS and non-CONUS sources.
Weather menu options are Composite and Base.
Source Options:
Composite (CONUS)
Composite reflectivity image of radar
for the conterminous U.S.
Precipitation above 52º N may display as mixed precipitation regardless of actual
precipitation type. Precipitation of an unknown type always displays as rain.
190-02327-03 Rev. C
Depending on the SXM service and installed GDL
hardware, radar base reflectivity imaging may have
broader coverage within North America or be limited
to only Canada.
Base
Base reflectivity image. Coverage
and availability are dependent
upon subscription.
Pilot's Guide
Hazard Awareness
5-15