Thunderstorms - Garmin G500 Pilot's Manual

Cover TOC
Weather
Mode
Approximate
Color
Intensity
BLACK
< 23 dBZ
GREEN 23 dBZ to < 33 dBZ
YELLOW 33 dBZ to < 41 dBZ
RED 41 dBZ to < 50 dBZ
MAGENTA
50 dBZ and greater
WHITE
4.8.5.2

Thunderstorms

Updrafts and downdrafts in thunderstorms carry water through the cloud.
The more severe the drafts, the greater the number and size of the precipitation
droplets. With this in mind, the following interpretations can be made from what
is displayed on the weather radar. Avoid these areas by an extra wide margin.
• In areas where the displayed target intensity is red or magenta (indicating
large amounts of precipitation), the turbulence is considered severe.
• Areas that show steep color gradients (intense color changes) over thin bands
or short distances suggest irregular rainfall rate and strong turbulence.
• Areas that show red or magenta are associated with hail or turbulence, as
well as heavy precipitation. Vertical scanning and antenna tilt management
may be necessary to identify areas of maximum intensity.
Along squall lines (multiple cells or clusters of cells in a line), individual cells
may be in different stages of development. Areas between closely spaced, intense
targets may contain developing clouds not having enough moisture to produce
a return. However, these areas could have strong updrafts or downdrafts.
Targets showing wide areas of green are generally precipitation without severe
turbulence.
Irregularities in the target return may also indicate turbulence, appearing as
"hooks," "fingers," or "scalloped" edges. These irregularities may be present in
green areas with no yellow, red, or magenta areas and should be treated as highly
dangerous areas. Avoid these areas as if they were red or magenta areas.
4-100
GWX 68 Radars
Approximate
Rainfall Rate
(in/hr)
< .01
.01 - 0.1
0.1 - 0.5
0.5 - 2
> 2
Table 4-26 Precipitation Intensity Levels
Garmin G500/G600 Pilot's Guide
GWX 70 Radars
Approximate
Intensity
< 23 dBZ
23 dBZ to < 33 dBZ
33 dBZ to < 41 dBZ
41 dBZ to < 50 dBZ
50 dBZ and greater
Turbulence Detection
3rd Party
Radars
Radar Return
Level (see
radar docu-
mentation
for details)
0
1
2
3
4
190-00601-02 Rev. J