In addition to the surface weather observations of temperature, precipitation and wind, Radiosonde observations began September 1,1939 with two flights a day which still continue at 12z and 00z through the present day.
In addition to the surface weather observations of temperature, precipitation and wind, Radiosonde observations began September 1,1939. At least 2 Radiosonde flights were done a day which still continues at 12z and 00z through the present day.