MODIFICATION OF REPORT
MESSAGE
The MRS coded message is in the proper WMO
International code but does not conform to the United
States national coding practice with regard to
significant level winds. By national coding practice, all
fixed and mobile land upper-air stations within the
United States do not report significant wind levels, but
only include fixed regional level winds. In addition,
fixed regional level winds are reported in the PILOT
code in message Parts B and D. However, U.S. Navy
ships, even though they may be operating within WMO
Region IV, report significant winds levels only in Part B
of the TEMP code.
U.S. Naval ships may use Additional Data groups,
the so-called "101-code groups" (table 1-6), as
specified by WMO Region IV practice, even when
operating outside the region. These codes must be used
by all mobile and fixed land stations within North
America, the eastern Pacific, and the Caribbean. These
data groups are not encoded by the MRS, but must be
manually entered. The 101-codes are used following
the "51515" Regional Data Identifier group, as
appropriate, in sections B and D of the TEMP codes.
Designated Synoptic stations use many of these 101
codes to indicate why a report for a scheduled sounding
is not available at the normal time. Most Navy and
Marine Corps upper-air observers use the code groups
to explain the reason for sounding termination, to
indicate levels of doubtful data, and to report corrected
data. The FMH-3 contains a complete list of all 101
code groups. We will discuss where and how these
codes groups are used within the TEMP code later in
this chapter. In addition to the 101 codes, most ships
insert the balloon release height immediately after the
Table 1-6.—Region IV Additional Data Groups
10154 Local radio interference
AND UPPER LIMITS OF DATA
10155 Fading signal
10165 Altitude and temperature doubtful
10156 Weak signal
10166 Altitude doubtful
10158 Flight equipment failure (radiosonde, balloon, etc.) 10167 Temperature doubtful
10159 Any reason not listed above
10168 Dew-point depression doubtful
10187 Surface data
10188 Additional data
DOUBTFUL DATA FOLLOWED BY ONE OR
MORE OPnPnPnPn GROUPS, FOR LOWER
10150 Ascent did not reach 400 hPa level
10151 Balloon forced down by icing
10152 Balloon forced down by precipitation
10153 Atmospheric radio interference
REASON FOR NO REPORT OR AN
CORRECTED DATA FOLLOWS
INCOMPLETE REPORT
10140 Report not filed
10178 Tropopause data
10141 Incomplete report; full report to follow
10179 Maximum wind
10142 Ground equipment failure
10180 Entire report (parts to follow A, B, C, and D)
10143 Observation delayed
10181 Parts A and B
10144 Power failure
10182 Parts C and D
10145 Unfavorable weather conditions
10183 Parts A and C
10146 Low maximum altitude (less than 1500 feet AGL)
10184 Parts B and D
10147 Leaking balloon
10185 Minor error in this report. correction follows
10149 Military operations preclude sounding
10186 Additional significant levels not in original
report follow
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