How Coded Wartime Forecasts Kept Intelligence Out of Enemy Hands
Data security is far from a purely modern concern, as demonstrated by a fascinating chapter from the Second World War. The BBC, which had broadcast daily weather forecasts since 1923, abruptly ceased this public service immediately after the war began. Continuing these broadcasts would have provided the German military, particularly the Luftwaffe, with critical meteorological intelligence that could have been exploited for planning bombing raids and other operations.
The Switch to Coded Agricultural Bulletins
While the general public lost access to weather information, certain groups—especially farmers who relied on forecasts for agricultural planning—still required this data. To address this need while maintaining security, the Met Office developed a system of coded agricultural forecasts known as Pabulum. These bulletins used clever substitutions, with animal names representing weather conditions and financial terms indicating weather quality.
For instance, "Buy" signaled good weather while "Sell" indicated poor conditions. A specific example: "Fat Cow" meant rain in the morning that would improve later in the day. This ingenious coding allowed essential information to reach those who needed it without revealing sensitive details to potential enemy listeners.
Railway Announcements Under Wartime Restrictions
The restrictions extended beyond broadcast media to everyday communications. Railway station announcers, who before the war could freely explain delays caused by weather conditions like fog, snow, or leaves on the line, were now prohibited from such disclosures. Wartime posters advised the public through rhyme about these new constraints:
"In peacetime railways could explain/ When fog or ice held up your train/…, Now think of this, if it’s your fate / To have to meet a train that’s late, / Railways aren’t allowed to say /What delayed the trains to-day."
This comprehensive approach to information control demonstrates how thoroughly British authorities worked to prevent any weather-related intelligence from reaching enemy hands during the conflict.
