Garmin G1000 Pilot's Manual page 318

HAZARD AVOIDANCE
NEXRAD
NEXRAD cannot be displayed at the same time as echo tops, icing, turbulence, terrain data, or
NOTE:
airborne weather radar information is displayed.
The National Weather Service (NWS) operates the WSR-88D, or NEXRAD (NEXt-generation RADar)
system, an extensive network of 156 high-resolution Doppler radar systems. The NEXRAD network provides
centralized meteorological information for the continental United States and selected overseas locations. The
maximum range of a single NEXRAD site is 250 nm.
Individual NEXRAD sites supply the network with radar images, and the images from each radar site may
arrive at the network at different rates and times. Periodically, the weather data provider compiles the available
individual site images from the network to form a composite image, and assigns a single time to indicate when
it created the image. This image becomes the NEXRAD weather product. Individual images--gathered from
each NEXRAD site--differ in age, and are always older than the displayed NEXRAD weather product age. The
data provider then sends the NEXRAD data to the SiriusXM Weather service, whose satellites transmit this
information during the next designated broadcast time for the NEXRAD weather product.
Because of the time required to detect, assemble, and distribute the NEXRAD weather product, the displayed
weather information contained within the product may be significantly older than the current radar synopsis
and may not depict the current weather conditions. The NEXRAD weather product should never be used as a
basis for maneuvering in, near, or around areas of hazardous weather regardless of the information it contains.
For radar sites in the United States, the NEXRAD weather product shows a composite reflectivity image.
This shows the highest radar energy received from multiple antenna tilt angles at various altitudes. For radar
sites based in Canada, the NEXRAD weather product shows radar returns from the lowest antenna tilt angle,
known as base reflectivity. The display of the information is color-coded to indicate the intensity of the echoes
and the type of precipitation, if known.
302
Figure 6-10 NEXRAD Data on the Weather Data Link (XM) Page
Garmin G1000 Pilot's Guide for the Diamond DA42NG
No Radar Coverage
190-00-00962-04 Rev. A