The Zambretti Forecaster was developed around 1915 by the Negretti & Zambra (Zambretti) company of London. Using barometric pressure, trend, seasonality, and wind direction; a forecast for the next 12-24 hours is generated. Zambretti sold a number of versions of the forecaster over the years, including models made of brass, plastic, and desktop versions. A number of electronic devices implement the forecasting algorithm, and testing has shown that devices implementing the algorithm properly are over 87% accurate
Development
According to the original UK Patent, the Zambretti forecaster was the result of “over 10 years of research”, by a Eric Wilfred Kitchen; a mechanical engineer likely contracted under Negretti & Zambra to create the device. There’s not much else known about how the forecast was developed- much like the Sager Weathercaster, likely statistical modeling and observational rules of thumb over long periods.