Weather Wednesday: telegraphic coded weather observations

BISMARCK — Bismarck, Omit, Leafage, Buck, Bank. That was the telegraphic code found on this thin piece of paper, hidden in this silk dress from the 1800s.

Wayne Chan decoded the mysterious message which turned out to be a meteorological one, detailing the weather conditions on May 27, 1888. “I’ve never seen any code that wasn’t meant for secrecy be so complex.”

But in the 1800s the U.S. Army Signal Service used this complex code to send weather reports from across the country to the central Signal Service in Washington, DC through telegram, which charged by the word.

“Basically they’re trying to compress several variables down to one word to save money when they transmit the message,” Chan explains.

Here’s how it breaks down: the first word is the reporting weather station: Bismarck. The second word: OMIT represents temperature and air pressure: 56 degrees with a barometric pressure of 30.08”. The next word LEAFAGE is code for dew point and observation time: 32 degrees at 10pm eastern time. BUCK reveals the wind direction and precipitation, it was a dry day with a north wind. And the final word BANK translates the wind speed of 12mph and sunset conditions which were clear on May 27, 1888.

These condensed weather reports in the beginning of the telegraph era were sent to the D.C. weather office three times a day where meteorologists there would decode the messages and create a national weather map of current conditions… a collection of reports traveling faster than the weather for the first time in history.

Meteorologists would use these weather observations as a base for creating a national forecast within two and a half hours of receiving the reports. The forecast would then be sent through telegram to cities and newspapers across the Union, to help alert people of what type of weather was heading their way… all thanks to these condensed, coded messages.

“It’s kind of like texting, you are compressing and using abbreviations and emojis to compress the message,” Chan adds. Though 136 years later, a text of Bismarck, Unit, Lashing, Silvan, Noisy, Ice would be difficult for to decipher, especially without the correct codebook.

Many weather stations in the 1800s were located near the telegraph office so the reports could be quickly transmitted since they had high priority. Telegraph operators were supposed to send the weather reports before almost anything else.