Nexrad Limitations - Garmin G500 Pilot's Manual

4.7.5.2

NEXRAD Limitations

NEXRAD radar images may have certain limitations:
• NEXRAD base reflectivity does not provide sufficient information to
determine cloud layers or precipitation characteristics. 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. It has no information about storms directly over the site.
• When zoomed in to a range of 30 NM, each square block on the display
represents an area of four square kilometers. The intensity level reflected
by each square represents the highest level of NEXRAD data sampled
within the area.
The following may cause abnormalities in displayed NEXRAD radar images:
• Ground clutter
• Strobes and spurious radar data
• Sun strobes (when the radar antenna points directly at the sun)
• Interference from buildings or mountains, which may cause shadows
• Metallic dust from military aircraft, which can cause alterations in radar
scans
190-01102-02 Rev. B Garmin G500 Pilot's Guide
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