Using latitude, longitude, and the Marsden square number.
Part A contains information on mandatory levels at and below 100 hPa, and Part
C contains information on mandatory levels above 100 hPa.
To transmit available information from the lower levels of the atmosphere prior to
completion of the entire observation.
Mandatory levels at and below 100 hPa from a ship upper-air sounding.
When the wind speeds in an upper-air observation are measured in knots.
The sounding is from a fixed land site. The date of the sounding is the 9th of the
month at 12Z, and the wind speeds are in knots. Additionally, wind information is
available to at least the 150-hPa level.
99270 71520 08872.
Part A contains pressure-altitude, temperature, dew-point depression, and wind
direction and speed data for all mandatory levels up to 100 hPa. It also contains
tropopause and maximum wind data.
1,397 meters is the altitude of the 850-hPa level.
When the dew-point depression is 6.0°C or greater.
Wind direction is reported to the nearest 5 degrees and wind speed is reported to
the nearest whole knot (or meter per second).
The altitude of the 700-hPa level is 2,910 meters, the temperature is -9.1°C, the
dew-point depression is 13, the wind direction is 335°, and the wind speed is 14
Maximum wind is at 220 hPa at 075° at 102 knots, the absolute value of the vector
difference 3,000 feet below is 05 and 3,000 feet above is 08.
Part B contains significant temperature and humidity levels. It also may also
contain significant level winds, system status and observation time, sea surface
temperature data, as well as cloud information and regional and national coded
The observed cloud data.
Significant level winds.
At least one additional level must be encoded between the lower and upper
boundary layers of the missing data.