4 GPSMAP 4000 Series Owner’s ManualuSInG XmUSinG XmUsing XM WX Weather and AudioIn order to use XM Weather, you must have a Garmin GDL 30 or 30A XM receiver and an activatedXM weather subscription. To use XM Audio, you must have the Garmin GDL 30A XM receiverand an XM Audio subscription. To connect the XM antenna and receiver and for subscriptioninstructions, refer to the GDL 30/30A Marine Weather Satellite Receiver Installation Instructions.If you do not have a receiver and a subscription to XM WX Weather, the weather features describedin this section work only when the unit is in Simulator Mode.Using XM WX WeatherThe GDL 30/30A receives XM WX Weather data and shows it on your unit’s Navigation chart andother screens throughout the unit. The weather data for each feature comes from reputable weatherdata centers such as the National Weather Service and the Hydrometerological Prediction Center.(See the XM WX Satellite Weather Web site at http://weather.xmradio.com/weather for moreinformation.)NOTE: Any weather feature can change in appearance or interpretation if the source that provides theinformation changes.XM WX Weather data is broadcast at set rates. For example, NEXRAD (NEXt Generation WeatherRADar) data is broadcast at five minute intervals. When the Garmin unit is turned on or when a newfeature is selected, the GDL 30/30A has to receive new data before it can be shown.NOTE: You might experience a delay before weather data or a new feature appears on the map.Setting the XM WX Weather OptionsTo configure the weather settings from the Home screen, select Weather > Weather Setup. Fromthis menu, you can turn the NEXRAD Loop on or off and hide or show the weather Legend.Viewing Precipitation InformationPrecipitation shows NEXRAD radar, storm cells, lighting strikes, and hurricane warnings. To viewprecipitation from the Home screen, select Weather > Precipitation.Viewing NEXRAD Radar InformationNEXRAD shows precipitation from very light rain and snow up to strong thunderstorms in varyingshades and colors. On the GPSMAP 4000 series unit, you can view NEXRAD information as animage of the latest update, or as an animated loop of the latest updates. To animate the NEXRADloop, from the Home screen, select Weather > Weather Setup > NEXRAD Loop > On.In the lower-left corner of the screen is a Time Stamp. The Time Stamp displays the elapsed timesince the National Weather Service last updated the information.