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Section 2
NEXRAD Overview
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 400/500 Series units using colors represented by the dBz values listed in Table 2-1.
Display dBZ Rain
(inches/hour)
Snow
(inches/hour)
Remarks
GDL 49 GDL 69
Atmos Cloud Rain Snow Sleet Hail
<-10 .00” .00”
-10 .00” .00”
-5 .00” trace
0 .00” trace - .05”
Very Light
5 .00” trace - .10”
Light
10 0” – trace .10”
Light Light
15 .01” .1-.2” Light Light
20 .02” .2-.3” Light Light
25 .05” .3-.5” Light Light – Medium
30 .09” .5-.7” Light – Moderate Moderate
35 .24” .7-1.0” Moderate Heavy
40 .48” 1”+, or sleet Heavy Heavy
45 1.25” 1”+, or sleet Heavy Heavy
50 2.5” sleet Intense
55 5.7” sleet Extreme
60 12.7” Extreme
65 Extreme
70 Large
75 Large
The information presented in this Pilot’s Guide regarding
NEXRAD is not meant to be comprehensive. The NOAA website
contains complete and detailed information regarding NEXRAD
weather radar operation and theory. You can visit them at
www.noaa.gov.
Table 2-1 NEXRAD Intensity Colors
