Hazard Avoidance - Garmin G300 Pilot's Manual

The display of radar coverage is always active when NEXRAD is selected. Areas
where NEXRAD radar coverage is not currently available or is not being collected
are indicated in grayish-purple (Weather (WX) Page Only). Radar capability exists
in these areas, but it is not active or is off-line.
neXRAD A
There are possible abnormalities regarding displayed NEXRAD images. Some,
but not all, of those include:
• Ground clutter
• Strobes and spurious radar data
• Sun strobes, when the radar antenna points directly at the sun
• Military aircraft deploy metallic dust (chaff) which can cause alterations in
radar scans
• Interference from buildings or mountains, which may cause shadows
neXRAD l
Certain limitations exist regarding the NEXRAD radar displays. Some, but not
all, are listed for the user's awareness:
• NEXRAD base reflectivity does not provide sufficient information to determine
cloud layers or precipitation characteristics (hail vs. rain). For example, it is
not possible to distinguish between wet snow, wet hail, and rain.
• NEXRAD base reflectivity is sampled at the minimum antenna elevation angle.
An individual NEXRAD site cannot depict high altitude storms at close ranges,
and has no information about storms directly over the site.
• Radar coverage only extends to 55°N.
• Any precipitation displayed between 52°N and 55°N is unknown.
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Garmin G300 Pilot's Guide

hazard avoidance

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