4-39190-01102-02 Rev. E Garmin G500 Pilot’s GuideForewordSec 1SystemSec 2PFDSec 3MFDSec 4HazardAvoidanceSec 5AdditionalFeaturesSec 6Annun.& AlertsSec 7SymbolsSec 8Glossary Appendix AAppendix BIndex4.8.5.2 NEXRAD LimitationsNEXRAD radar images may have certain limitations:• NEXRAD composite reflectivity does not provide sufficient informationto determine cloud layers or precipitation characteristics. For example, itis not possible to distinguish between wet snow, wet hail, and rain.• NEXRAD composite reflectivity is sampled at the minimum antennaelevation angle. An individual NEXRAD site cannot depict high altitudestorms at close ranges. It has no information about storms directly overthe site.• When zoomed in to a range of 30 NM, each square block on the displayrepresents an area of four square kilometers. The intensity level reflectedby each square represents the highest level of NEXRAD data sampledwithin 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 radarscans
