Garmin G3X Pilot's Manual page 238

Hazard Avoidance
• Interference from buildings or mountains, which may cause shadows
• Poor reception from Ground Based Transceivers (GBTs) can cause portions of the
received radar imagery to not be displayed
NEXRAD Limitations
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.
neXraD i
Colors are used to identify the different NEXRAD echo intensities (reflectivity)
measured in dBZ (decibels of Z). "Reflectivity" (designated by the letter Z) is the
amount of transmitted power returned to the radar receiver. The dBZ values increase
as returned signal strength increases. Precipitation intensity is displayed using colors
corresponding to the dBZ values.
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ntenSity
RADAR Legend
Garmin G3X Pilot's Guide
NEXRAD Data
190-01115-00 Rev. K