METEOROLOGY FLIGHT PLANNING
have comments made in the remarks section (Part IV) to elaborate on the warning. The next
set of boxes can be checked to indicate the type and amount of coverage, in addition to providing
the maximum cloud tops of the thunderstorms, when that information is available, along with the
geographic location where the aircrew can expect to encounter the indicated thunderstorm
activity. More than one box may be checked to indicate various possible conditions, so aircrew
should be sure to ask for further details if the explanation given during the brief is unclear.
Finally, observe the typed notice above the location box that reads, "Hail, severe turbulence and
thunderstorms." This is yet another reminder of the extremely hazardous nature of
thunderstorms. Even though there is little extra space on the DD 175-1, some experienced
aviators and meteorologist thought that it was very important for aviators to read this message
every time their attention is focused on Block 21 (Figure 4-5).
Figure 4-5 Part II: En Route Data Section
Block 22: Turbulence
The format of the Turbulence Block is similar to that of the Thunderstorm Block, beginning with
a section for advisories, any of which should also have further remarks made in Part IV. Since
turbulence will be experienced in all thunderstorms, this section is only for turbulence not
associated with thunderstorms. Good sources of forecast information include the WS, WA
(Tango), Surface Prognostic Chart, and Low-Level Significant Weather Prognostic Chart.
PIREPs, when available, are also an excellent source of observed information on turbulence.
Blocks 23 and 24: Icing and Precipitation
Much like the sources for turbulence, the icing sources include the WS, WA (Zulu), Surface
Prognostic Chart, and Low-Level Significant Weather Prognostic Chart, and PIREPs. Also, like
FLIGHT WEATHER BRIEFING FORM, DD FORM 175-1 4-9