(if located higher than 100 hPa), and maximum wind
data (if located higher than 100 hPa).
If the upper-air sounding terminated below the 100-
hPa level. Part C of the message may be encoded and
transmitted including only the appropriate
identification data followed by the code 51515 and the
reason for termination code.
PART D - UPPER SIGNIFICANT
Part D is used to report significant temperature and
humidity levels, significant wind levels, and regional
codes in the same manner as reported in Part B. Section
7, for sea-water temperature and the rawinsonde system
information. and section 8. for cloud information, are
never included in Part D. Coded regional information,
such as the 101 -groups. arc included as appropriate for
any levels above 100 hPa.
Early Transmission messages are brief reports of
certain observed upper-air data. which are sent as soon
as possible after the radiosonde measures the 500-hPa
level. Normally, these messages are manually encoded
by all ships and designated synoptic land stations while
the MRS continues to receive and process data. These
messages contain only the appropriate Part B
identification data, followed by, the code groups 51515
10196 and data for the 850-, 700-. and 500-hPa levels
(as normally transmitted in Part A). Land stations may
also include the stability) index and the low-level mean
winds. The 10196 group identifies the data as an "early
In addition to encoding Parts A through D of the
TEMP code, certain stations must encode some data in
the PILOT code, which is discussed in the following
How should the following data "31313 46105
82325 90173" be decoded?
In what part of a TEMP coded message would
you expect to find data for the 70-hPa level?
Early Transmission messages report
information up to what level?
LEARNING OBJECTIVES: Identify the three
forms of the PILOT code and explain the use of
each form. Identify the type of information
contained in each message part and the
meaning of each coded element. Describe the
special use of the PILOT code for Rawinsonde
observations conducted within WMO Region
The PILOT code is primarily used throughout the
world to report PIBAL-observed wind directions and
speeds. In the United States, it is also used to report
fixed regional level winds observed during a
Like the TEMP code, the PILOT code is also
separated into four parts to ease handling and speed
transmission. Parts A and C include winds observed at
the standard altitudes for the mandatory pressure levels.
Parts B and D include winds for the significant wind
levels. Parts A and B are for levels from the surface to
100-hPa (about 53,000 feet), while Parts C and Dare for
levels above the standard 100-hPa level. Each part
begins with an identification Data section.
What Information is contained in Part B of a
TEMP coded message?
Q57. What information is contained in section 8 in
Part B of a TEMP coded message?
Q 5 8 . The 21212 indicator group is followed by what
type of information?
Q59. How are boundaries of missing data encoded in
There are three forms of the PILOT code prescribed
for use by the WMO. WMO code FM 32-1X PILOT is
used by designated shore stations to report upper-air
observations of wind information. The code identifiers
PPAA, PPBB, PPCC, and PPDD are used to identify
this code form. FM 34-1X PILOT MOBIL is used by
mobile sites ashore to report atmospheric wind
observations. The code identifiers EEAA. EEBB,
EECC, and EEDD are used to identify thiscode. At sea.
shipboard upper-wind observations are reported in
WMO code FM 33-1X PILOT SHIP using the
identifiers QQAA, QQBB, QQCC, and QQDD. Each
code form is nearly identical in format except for the
identification information contained in the first line of
each message part.