Garmin 190-01030-02 ユーザーズマニュアル

The GXM 51 receives XM Weather Radio data and shows it on your chartplotter. The weather data for each feature 

comes from reputable weather data centers such as the National Weather Service and the Hydrometerological 

Prediction Center. (See the XM WX Satellite Weather Web site at 

 for more 

information.) Any weather feature can change in appearance or interpretation if the source that provides the 

information changes. XM Weather Radio data is broadcast at set rates. For example, NEXRAD Radar data is 

broadcast at five minute intervals. When the marine network is turned on or when a new feature is selected, the 

GXM 51 has to receive new data before it can be displayed. For this reason you may experience a delay before 

weather data or a new feature appears on the map.

WARNING: The XM Weather Radio data is merely supplemental and advisory in nature and is not intended to be 

relied up on as safety-critical information. You should always exercise caution and common sense when confronted 

with severe weather conditions.
WARNING: XM WX Weather should not be used for hazardous weather penetration. Weather information is 

approved only for weather avoidance, not penetration.

NEXRAD

5

Cloud Tops

15

Storm Cells

1.25

Lightning

5

Wind

12

Pressure

12

Hurricanes

12

Visibility

12

Fronts

12

Sea-Surface Temperature

12

Wave Height

12

Wave Period

12

Wave Direction

12

Current Conditions

12

Forecasts

12

Sea-Surface Conditions

12

NEXRAD Radar is a Doppler radar system that has greatly improved the detection of meteorological events such 

as thunderstorms, tornadoes, and hurricanes. An extensive network of NEXRAD stations provides almost complete 

radar coverage of the continental United States, Alaska, and Hawaii, and the majority of Canada. The range of each 

NEXRAD is 124 nautical miles.

There are possible abnormalities regarding displayed NEXRAD images. Some, but not all, of those include the 

following circumstances:
Ground clutter
Strobes and spurious radar data
Sun strobes, when the radar antenna points directly at the sun
Military aircraft deployment of metallic dust (chaff), which can cause alterations in radar scans
Interference from buildings or mountains, which may cause shadows
NEXRAD Limitations
Certain limitations exist regarding the NEXRAD radar displays. Some, but not all, are listed here for your awareness:
NEXRAD base reflectivity does not provide sufficient information to determine cloud layers or precipitation 

characteristics (for example, determining between hail and rain).