SECTION 10
ADDITIONAL FEATURES
NEXRAD Intensity
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 on the GPS 400 units using colors
represented by the dBZ values listed in Table 10-6.
Display
dBZ
GDL 49
GDL 69
<-10
-10
-5
GREEN
10
GREEN
15
20
25
30
YELLOW
YELLOW
35
40
45
RED
RED
50
55
60
65
70
75
NOTe: The information presented in this Pilot's Guide regarding NeXraD is not meant to be comprehensive.
The NOaa website (www.noaa.gov) contains complete and detailed information regarding NeXraD weather
radar operation and theory.
10-20
Rain
Snow
(inches/hour)
(inches/hour)
.00
.00
.00
.00
.00
trace
0
.00
trace - .05
5
.00
trace - .10
0 – trace
.10
.01
.1-.2
.02
.2-.3
.05
.3-.5
.09
.5-.7
.24
.7-1.0
.48
>1 or sleet
1.25
>1 or sleet
2.5
sleet
5.7
sleet
12.7
Table 10-6 NEXRAD Intensity Colors
GPS 400 Pilot's Guide and Reference
Source of NEXRAD Echo
Cloud
Atmos
Rain
√
√
√
√
√
√
√
√
√
√
√
Light
Light
Light
Light
Light – Moderate
Moderate
Heavy
Heavy
Intense
Extreme
Extreme
Extreme
Snow
Sleet
Hail
Very Light
Light
Light
Light
Light
Light – Medium
Moderate
Heavy
√
Heavy
√
Heavy
√
√
√
√
√
√
√
Large
Large
190-00140-60 Rev. H