Garmin G900X Pilot's Manual - page 338

Garmin G900X Pilot’s Guide

190-00726-00  Rev. A

6-12

HAZARD AVOIDANCE

NEXRAD L

IMITATIONS

NEXRAD radar images may have certain limitations:

• NEXRAD base reflectivity does not provide sufficient information to determine cloud layers or precipitation 

characteristics (wet 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.  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 (Figure 6-12).

Figure 6-12  NEXRAD Data - Zoomed 

Block Area is 4 km

2

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