21212 indicator group is not included. Winds are
encoded in sets of three fixed levels, from lower to
higher. Each set is preceded by an identifier group
9tnu1u2u3 or 8tnu1u2u3. Identifier groups beginning
with a 9 are used when the fixed levels are separated by
300 meter (1,000 foot) increments, as used in WMO
Region IV. An indicator "1" replaces the indicator "9"
when the heights exceed 30,000 meters (100,000 feet).
The "8" indicator means that the fixed levels are
separated by 500-meter increments. The tn is the tens
digit of the first altitude reported in the set; the u1, u2
and u3 are the units digits of the level number.
Essentially, as used by the United States, tn is the
ten-thousands value of the altitude in feet, and the u1, u2.
and u3 are the thousands value of the altitude in feet. For
example, "91246 27575 27090 26606" indicates winds
for the 12,000 foot (MSL), 14,000-foot (MSL), and the
16,000-foot (MSL) fixed regional levels, respectively,
as 275° at 75 knots, 270° at 90 knots, and 265° at 106
knots. Refer to table 1-5 for a listing of the fixed
regional levels used in WMO Region IV.
Regional Codes
Regional codes may be added to the report
following the "51515" through "59595" group and
national codes from "61616" through "69696" indicator
group, as appropriate. In WMO Region IV, only the
51515 group is used. The Additional Data Codes or
101-groups, as discussed previously, may be added
when encoding a Pibal observation. The indicator and
the 101 -groups are not included when using the PILOT
code Part B (or Part D) to report fixed regional level
winds observed during a rawinsonde observation, since
this would duplicate information previously
transmitted.
PART C - UPPER MANDATORY LEVELS
Part C of the PILOT code is formatted exactly as
Part A. Only the mandatory levels above the standard
altitude of the 100-hPa level are reported in Part C.
PART D - UPPER SIGNIFICANT LEVELS
Significant level winds or fixed regional level
winds for the levels higher than the 100-hPa level are
reported in Part D. The format is exactly the same as
Part B.
REVIEW QUESTIONS
Q63.
What information is contained in Part A of the
PILOT code?
Q64.
Q65.
Q66.
Q67.
Q68.
Q69.
What does the indentifier EEBB of the PILOT
code indicate?
How would the information "44370 33030
35565 32082" be decoded from Part A of a
PILOT coded message?
The group 77PmPmPm is used to indicate what
information in a PILOT coded message?
What is the minimum wind speed required for a
wind level to be classified as a maximum wind?
When reporting fixed regional level winds in
Part B of the Pilot Code. how would "90346
09012 10015 12520" be decoded?
What information is contained in Part D of the
PILOT code?
OBSERVATION RECORDS
LEARNING OBJECTIVES: Identify the
records that must be maintained by upper-air
observers, and explain the proper disposition of
these records.
SECNAVINST 5212.5, the Navy and Marine
Corps Records Disposition Manual, identifies
meteorological records, such as upper-air observations
(except those conducted only for training), as
permanent official records of the U.S. Government. As
such, the original sounding records must be forwarded
to FNMOD. Asheville, North Carolina, at the end of
each month in accordance with NAVMET-
O C C O M I N S T 3 1 4 0 . 1 , U n i t e d S t a t e s N a v y
Meteorological and Oceanographic Support System
Manual. Duplicate copies of sounding records are
temporary records that may be retained on board as long
as they are useful, normally 1 year, and then destroyed.
PAPER RECORDS
When an upper-air sounding is conducted by using
the MRS. the sounding records are considered to be the
original printouts of the raw data, the printouts of the
mandatory and significant levels (LIST), and the
printout of the coded message (TEMP), including any
operator entered data. The printout should be neatly
folded in standard page size (8.5 by 11 inches) and
mailed in a large envelope. DO NOT separate the
continuous feed printer paper into individual sheets.
Each sounding printout should be arranged in
chronological order and identified with complete
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