(1)      When wind data are missing for one or more isobaric surfaces but are available for other isobaric surfaces below and above, a group (or groups) of solidi shall be included for the missing data.

(2)      The wind group shall be omitted in the case of those isobaric surfaces for which no data are available, provided wind data are not available for any still higher surface.

(3)      Code figure I_d = 0 shall refer to the 1000-hPa level.

(4)      When wind data are not available for any standard isobaric surfaces (either in Part A or in Part C), I_d shall be reported by means of a solidus (/).

(5)      When the wind group relating to the surface level shall be included in the report; when the corresponding wind data are not available, this group shall be coded /////.

M_iM_i type of report
   TT = TEMP REPORT (FM 35)
   UU = TEMP SHIP (FM 36)
   XX = TEMP DROP (FM 37)
   II = TEMP MOBIL (FM 38)

M_jM_j part or report transmitted
   AA = Part A
   BB = Part B
   CC = Part C
   DD = Part D

*         Used in FM 35 only
**       Used in FM 36 and FM 38 only
***     Used in FM 36, FM 37, and FM 38 only
****   Used in FM 38 only

D....D      ship or mobile land station call sign consisting of three or more alphanumeric characters--includes mobile land station observations or issuance of a radiological report on a routine basis and/ or in case of accident. It is recommended that this group be encoded in the form A₁A₂DDD, where A₁A₂ are the two-letter geographical designators related to countries or territories as specified in of the Manual on the Global Telecommunications System (Volume 1, Table C1, Part 1, Attachment II-5). DDD are location designators comprising the first three letters of the name of the town or commune where the mobile land station carries out upper-air reporting.

IIiii      WMO index number assigned to a fixed land station

99L_aL_aL_a      Q_cL_oL_oL_oL_o   MMMU_LaU_Lo       replacement group for IIIiii of the report for a sea station, aircraft or a carrier balloon, or a mobile land station.

99      data on position to follow

L_aL_aL_a      latitude in tenths of a degree

Q_c      quadrant of the globe (Code Table 3333, WMO No. 306)

L_oL_oL_oL_o      longitude in tenths of a degree

MMM      Marsden square number in which station is located at observation time (Code Table 2590)

U_La      unit digit of reported latitude

U_Lo       unit digit of reported longitude

h₀h₀h₀h₀i_m      elevation of mobile land station, units of elevation, and elevation accuracy

h₀h_oh₀h₀      elevation in meters or feet as indicated by i_m

i_m      indicator for units of elevation and confidence factor of accuracy (Code Table 1845) assigned or an identification group assigned for the duration of the activity which the station is supporting. If possible, the mobile station should maintain the same identification for the duration.

YY      Day of the month (UTC), (01 indicating the 1st day, 02 the 2nd day, etc.) on which the actual time of observation falls. YY shall also be used to indicate the unit of wind speed in addition to indicating the day of the month. When wind speeds are given in knots, 50 shall be added to YY. When the speed is given in meters per second, YY shall not be modified.

GG      Actual time of observation to the nearest whole hour UTC. In the case of upper-air observations, the actual time of observation is the time at which the balloon is actually released.

I_d      Indicator used to specify the hundreds of hectopascals figure (in Part A of TEMP, TEMP SHIP, and TEMP MOBIL reports) or tens of hectopascals figure (in Part C of TEMP, TEMP SHIP, TEMP DROP and Temp MOBIL reports) of the pressure relative to the last standard isobaric surface for which the wind is reported

The data groups for the surface level and the standard isobaric surfaces of 1000, 925, 850, 700, 500, 400, 300, 250, 200, and 100 hPa shall appear in Part A in ascending order with respect to altitude.

For Part C the standard isobaric surfaces are 70, 50, 30, 20, 10, 7, 5, 2, and 1 hPa.

When the geopotential of a standard isobaric surface is lower than the altitude of the reporting station, the air temperature-humidity group for that surface shall be included. Solidi (/////) shall be reported for these groups. The wind groups for these levels shall be included as specified by the value reported for symbol I_d.

When wind data are available for all levels, the wind group shall be included for each level as indicated in the symbolic code form. If wind data are not available for all levels, the procedures given below shall be followed:

99P₀P₀P₀    T₀T₀T_a0D₀D₀    d₀d₀f₀f₀f

99      data for the surface level follows

P₀P₀P₀      Pressure from the surface through 100 hPa shall be reported to whole hPa. Pressures < 100 hPa, report to tenths of a hPa.

T₀T₀      Tenths and units digits of air temperature not rounded off, in ^OC at the specified levels starting with station level.

T_a0      Tenths of degrees temperature shall be indicated by means of T_a0, T_a1,..., T_an

D₀D₀      Dewpoint depression at standard isobaric surfaces or at D₁D₁ significant levels, starting with station level (use WMO Code Table 0777)

I_d      Indicator used to specify the pressure relative to the last standard isobaric surface for which a wind is reported (WMO Code Table 1734).

d₀d₀      True direction (rounded off to the nearest 5^O), in tens of degrees from which the wind is blowing at specified levels starting with surface level

f₀f₀f₀      Wind speed in knots (or meters per second depending on YY) starting with station level

When more than one tropopause is observed, each shall be reported by repeating Section 3.

When no tropopause data are observed, the group 88999 shall be reported for Section 3.

88P_tP_tP_t T_tT_tT_atD_tD_t      Data for tropopause levels
or
88999

P_tP_tP_t       Pressure at the tropopause levels. The pressures of the level(s) greater than and including the 30 hPa surface shall be reported in whole hectopascals.

T_tT_t      Air temperature in whole degrees Celsius at the tropopause level. This temperature, measured in degrees and tenths, is not rounded off to the next whole degree; only the whole degrees are indicated by T_tT_t. The tenths of this temperature shall be indicated by means of T_at.

T_at      Approximate tenths value and sign (plus or minus) of the air temperature at the tropopause level (Code Table 3931).

88999      When no tropopause data are observed, 88999 shall be used for Section 3.

When more than one maximum wind level is observed, each shall be reported by repeating Section 4.

When no maximum wind level is observed, the group 77999 shall be reported by for Section 4.

Indicator figures 77 shall be used when the level(s) for which maximum wind data are reported does not coincide with the top of the wind sounding corresponds to the highest wind speed observed throughout the ascent. For the purpose of the above regulation, the "top of the wind sounding" is to be understood as the highest altitude level for which wind data are available.

Group (4v_bv_bv_av_a) shall be included only if data for vertical wind shear are computed and required.

77 or 66      Indicator for maximum wind level(s) and wind shear. Indicator figure 77 shall be used when the level(s) for which maximum wind data are reported does (do) not coincide with the top of the wind sounding. Indicator figures 66 shall be used in the opposite case, i.e. whenever the top of the wind sounding corresponds to the highest wind speed observed throughout the ascent. The top of the wind sounding is to be understood as the highest level for which wind data are available.

P_mP_mP_m      Pressure at the maximum wind level. (1) The pressures from the surface including the 100-hPa surface shall be reported in whole hPas. For a pressure level less than 100-hPa surface, pressure shall be reported in tenths of a hectopascal.

d_md_m      True direction (rounded off to the nearest 5^O), in tens of degrees, from which maximum wind is blowing.

f_mf_mf_m       Maximum wind speed in meters per second or knots. (1) When encoding wind direction that has been rounded off to the nearest 5^O, the hundreds and tens figures of this rounded direction shall be reported by dd and the units figure shall be added to the hundreds figure of the wind speed. (2) The day of the month (UTC) shall be used to indicate the unit of wind speed in addition to indicating the day of the month. When wind speeds are given in knots, 50 shall be added to YY. When wind speed is given in meters per second, YY shall not be modified.

(4v_bv_bv_av_a)      Section containing wind shear.

v_bv_b      Absolute value of the vector difference between the maximum wind and the wind 1 km above the level of maximum wind, in units indicated by YY.

v_av_a      Absolute value of the vector difference between the maximum wind and the wind 1 km above the level of maximum wind, in units indicated by YY.

77999      When no maximum wind level is observed, the group 77999 shall be reported for Section 4.

If, in the determination of additional levels with respect to specified criteria for changes in air temperature and/or relative humidity, the criteria for either variable are satisfied at a particular point in altitude, data for both variables (as available) shall be reported for that level.

Dew-point data shall be derived using the function (or near equivalent) for the relationship between saturation vapor pressure over water and air temperature (Appendix D, Section D.5.) Dew-point data shall not be reported when the air temperature is outside the range stated by WMO for the application of the function; a lesser range may be used as a national practice.

The highest level for which a dew point is reported shall be one of the levels selected.

The reported additional levels alone shall make it possible to reconstruct the air temperature and humidity profiles within the limits of the criteria specified.

n₀n₀P₀P₀P₀    T₀T₀T_a0D₀D₀
n₁n₁P₁P₁P₁    T₁T₁T_a1D₁D₁
....                  ....
n_nn_nP_nP_nP_n   T_nT_nT_anD_nD_n

   n₀n₀    Number of level, starting with
   n₁n₁    station level. Station level shall be
   ...        coded n₀n₀=0
   n_nn_n

   P₀P₀P₀     Pressure at specified levels. The
   P₁P₁P₁     pressure of the surfaces up to and
   ...             including the 100-hPa surface shall
   P_nP_nP_n    be reported in whole hectopascals.
                   Above the 100-hPa surface,
                   pressure shall be reported in
                   tenths of a hectopascal.

   T₀T₀    Tens and units digits of air temperature
   T₁T₁    not rounded off, in degrees Celsius, at
   ...         specified levels starting with station
   T_nT_n    level.

   T_a0    Approximate tenths value and sign (plus
   T_a1    or minus) of the air temperature at
   ...      specified levels starting with station
   T_an    level (Code Table 3931).

The following shall be included as "mandatory significant levels":

(a) Surface level and the highest level of the sounding, or aircraft reference level and termination level for descent soundings.

(b) A level between 110 and 100 hPa;

(c) Bases and tops of inversions and isothermal layers which are at least 20 hPa thick, provided that the base of the layer occurs below the 300-hPa level or the first tropopause, whichever is the higher;

(d) Bases and tops of inversion layers which are characterized by a change in temperature of at least 2.5^OC or a change in relative humidity of at least 20 percent, provided that the base of the layer occurs below the 300-hPa level or the first tropopause, whichever is the higher;

D₀D₀    Dew-point depression at standard
D₁D₁    isobaric surfaces or at significant
...         levels, starting with station level.
D_nD_n   (Code table 0777)

Additional levels shall be chosen so that the data from them alone shall make it possible to reconstruct the wind profile with sufficient accuracy for practical use.

Note: Criteria for determining additional levels with respect to changes in wind speed and direction are given in Regulation 32.3.1.

21212   n₀n₀P₀P₀P₁   d₀d₀f₀f₀f₀
             n₁n₁P₁P₁P₁   d₁d₁f₁f₁f₁
             ...                  ...
             n_nn_nP_nP_nP_n  d_nd_nf_nf_nf_n

n₀n₀   Number of level, starting with
n₁n₁   station level. Station level
...       shall be coded n₀n₀.
n_nn_n

P₀P₀P₀   Pressure at specified levels. Pressure
P₁P₁P₁   levels from the surface up to and
...           P_nP_nP_nincluding the 100-hPa surface
              shall be reported in whole
              hectopascals. For pressures less than
              100-hPa surface, pressure shall be
              reported in tenths of a hectopascal.

d₀d₀   True direction (rounded off to the
d₁d₁   nearest 5^O ), in tens of degrees, from
...       which wind is blowing at specified
d_nd_n   levels starting with surface level. (1)
          When encoding wind direction that has
          been rounded off to the nearest 5^O, the
          hundreds and tens figures of this
          rounded direction shall be reported by
          dd and the units figure shall be added
          to the hundreds figure of the wind
          speed.

f₀f₀f₀   Wind speed in meters per second or
f₁f₁f₁   knots, at specified levels starting with
f_nf_nf_n  station level

(1)   When encoding wind direction that has been rounded off to the nearest 5^O, the hundreds and tens figures of this rounded direction shall be reported by dd and the units figure shall be added to the hundreds figure of the wind speed.
(2) YY   shall be used to indicate the unit of wind speed in addition to indicating the day of the month. When wind speeds are given in knots, 50 shall be added to YY. When the speed is given im meters per second, YY shall not be modified.

Section 7 is a mandatory section and shall always be reported. The group s_rr_ar_as_as_a and 8GGgg are mandatory for all TEMP, TEMP SHIP, and TEMP MOBIL. In TEMP SHIP reports, the group 9s_nT_WT_WT_W shall also be included.

31313 s_rr_ar_as_as_a 8GGgg (9s_nT_wT_wT_w)

s_r   Solar and infrared radiation correction (Code Table 3849).

r_ar_a   Radiosonde/sounding system used. (Code Table 3685)

s_as_a   Tracking technique/status of system used. (Code Table 3872)

8   Indicator for Greenwich time

GGgg   Time of observation, in hours and minutes UTC, the actual time of radiosonde release.

9   Indicator for

s_n   Sign of data, and relative humidity indicator (Code Table 3845)

T_WT_WT_W   Sea-surface temperature, in tenths of a degree Celsius, its sign being given by s_n.

In TEMP, TEMP SHIP, and TEMP MOBIL reports, this section shall be used to report cloud data. N_h, h, C_L, C_M, and C_H shall be coded in accordance with the regulations in FM 12 SYNOP.

41414   N_hC_LhC_MC_H      Section 8 Cloud Data

N_h   Amount of all the C_L present or, if no C_L is present, the amount of all the C_M cloud present. (WMO Code Table 2700)

C_L   Clouds of the genera Stratocumulus, Stratus, Cumulus and Cumulonimbus. (WMO Code Table 0513)

h   Height above surface of the base of the lowest cloud seen. (Code Table 1600) (1) the term "height above surface" shall be considered as being the height above the official aerodrome elevation or above station level at a non-aerodrome station, or above the surface of the water in reports from ships

C_M   Clouds of the genera Altocumulus, Altostratus, and Nimbostratus. (Code Table 0515) (1) The figure to be reported for C_M shall be determined on the basis of the detailed description of C_M clouds and illustrations of them in the International Cloud Atlas in conjunction with specifications in Code Table 0515.

C_H   Clouds of the genera Cirrus, Cirrocumulus and Cirrostratus. (Code Table 0509) (1) The figure to be reported for C_H shall be determined on the basis of the detailed description of C_H clouds and illustrations of them in the International Cloud Atlas in conjunction with specifications in Code Table 0509. (2) The figure C_H = 9 shall be used when the predominant C_H clouds are Cirrocumulus although small amounts of Cirrocumulus may be present in the C_H cloud system reported under C_H = 1 to 8.

WMO Region IV practice calls for additional information for pressure from the surface levels to and including the 100 hPa level shall be reported in this section by including supplementary groups.

51515     101A_dfA_df
52525
.....
59595

A_dfA_df Form of additional data reported (Code Table 421) 5

61616
62626     Code groups developed nationally
.....
69696

Place holder for Section 10