hi, i have got a mail reply from Foreflight. The following is their mail reply ForeFlight receives most US weather from the National Weather Service. Our radar and satellite maps come from WDT, which provides the best and most accurate composite radar data and satellite data for pilots. http://www.wdtinc.com/pages/ radar_mosaics Note that composite takes into account the radar returns at all altitudes, so it may differ from a NEXRAD image you may also be viewing. Take a look at that and let us know if you have any questions -- we're happy to help! Janessa Barber ForeFlight Pilot Support ForeFlight LLC