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PILOT CODE | Up
Aerographers Mate, Module 02-Miscellaneous Observations and Codes | Next
14270_43 |
IDENTIFICATION DATA
The identification data contains the data type, the
location identifier and/or location, and the date-time
group. The format is identical to the TEMP code, Part
B: MiMiMjMj YYGGa4 IIiii is used with the PILOT
code, while PILOT SHIP and PILOT MOBIL use
MiMiMjMj D....D YYGGa4 99LaLaLa QcLoLoLoLo
MMMULaULo hOhOhOhOim. The same identification
data format is used in all four parts of the report.
PART A - LOWER MANDATORY
LEVELS
Part A of the message contains identification data;
mandatory level winds. and the maximum wind and
wind shear values.
Mandatory Level Winds
After the identification data. the first section of the
PILOT code Part A is the winds at the mandatory levels
in the format 44nP1P1 or 55nP1P1 ddfff ddfff ddfff. The
55nP1P1 group is used only when the altitudes of the
pressure levels are based on standard altitudes above
mean sea level. The 44nP1P1 group is used when the
altitudes are obtained from pressure equipment. such as
a radiosonde. This cluster of four five-digit groups,
reporting winds at three mandatory levels, is repeated
four times to include all the mandatory levels through
the 100-hPa level.
In the first group. the n indicates the number of
standard levels reported in the section and the number of
ddfff groups that follow. This figure is usually a 3, but
may be a 1 or 2 in the last repetition. The P1P1 is the
hundreds and tens value of the first pressure level
reported.
The ddfff group reports wind directions (dd) and
wind speeds (fff). As in the TEMP code. the units of
wind speed are meters per second if the date, YY. in the
identification data is simply the UTC date. When the
wind speed units are reported in knots, 50 is added to the
date. All wind directions in the PILOT code are
reported to the nearest 5 degrees.
For example. the coded groups 43300 09535 08058
06601 indicate winds at three pressure levels (from a
radiosonde). starting at the 1,000-hPa level ("00"). 095°
at 35 knots: the 925-hPa level. 080° at 58 knots; and the
850-hPa level. 065° at 101 knots.
Maximum Wind
The following five different formats are used for the
indicator group of the level of maximum wind or a
secondary level of maximum wind:
66PmPmPm—maximum wind at top of sounding,
measured pressure level reported.
6Hm Hm Hm Hm —maximum wind at top of
sounding. standard altitude reported in meters.
77PmPmPm—maximum wind within sounding.
measured pressure level reported.
7HmHmHmHm—maximum wind within sounding.
standard altitude reported in meters.
77999—no maximum wind observed.
The PmPmPm is the measured pressure level in
hectopascals and HmHmHmHm is the altitude in
decameters (units rounded off. hundred-thousands
value not reported). A maximum wind level must have
a wind speed in excess of 60 knots and occur above the
500-hPa level. A secondary maximum wind level may
also be reported.
Following the maximum wind indicator group, the
wind is reported in the format ddfff, and the optional
vertical wind-shear group, 4vbvbvava, may be reported
the same as in the TEMP code.
PART B - LOWER SIGNIFICANT LEVELS
This part of the PILOT code message contains
identification data, reports of winds at significant
levels, and regional and national coded information for
the levels up through 100 hPa. In WMO Region IV, the
fixed regional levels (PPBB) replace any significant
levels (section 6, Part B of TEMP Code).
Significant Level Winds
When only significant levels are reported. as
indicated by the identifier group 21212. each level is
encoded in two five-digit groups in the format nnPPP
ddfff. The nn indicates the level (number 00 for surface,
and then upward from 11 through 99, and repeating as
necessary. The PPP is the pressure for the level. The
ddfff is the wind direction and speed, just as reported for
the mandatory levels.
Fixed Regional Level Winds
When this section is used to report winds at fixed
regional levels, a slightly different format is used. The
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