Thunderstorms - Garmin G500 Pilot's Manual

Weather Mode
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.
190-01102-02 Rev. B
Approximate
Color
BLACK
GREEN 23 dBZ to < 32 dBZ
YELLOW 32 dBZ to < 41 dBZ
RED 41 dBZ to < 50 dBZ
MAGENTA 50 dBZ and greater
Table 4-17 Precipitation Intensity Levels
Garmin G500 Pilot's Guide
Approximate
Rainfall Rate
Intensity
< 23 dBZ
(in/hr)
< .01
.01 - 0.1
0.1 - 0.5
0.5 - 2
> 2
4-71