Observational data extracted from the Met Office's MetDB system. Data include surface and upper air observations and some satellite data. These data are from a number of different message types covering data from land and ship surface data measurements through to upper air observations from wind profilers, radiosonde ascents and aircraft measurements and also satellite measurements.

Data arrive at the Met Office as per standard messages transmitted from source (e.g. SYNOP, METARS, TEMP message types) and are then decoded within the MetDB system. CEDA receives a text output from the MetDB system of these deciphered messages which are then processed into the BADC-CSV format where possible. Messages are split up by observation date at this stage. METARS and CLIMAT data are not decoded by the Met Office and are stored as per the original message. Details about the contents of each message type are given in the links in the 'online resources' section of this record. "Raw" data for all message types are available through the /raw folder within the archive. Each raw file contains messages received within a given period of time at the Met Office and are not sorted by observation date.