Zambretti Forecaster

It interprets the reading of a barometer into one forecast from a large selection of permutations after making allowances for variable factors.

These include wind direction, a rising, falling or steady barometer, and the season.

[1] Negretti and Zambra were scientific instrument makers, noted for their barometers.

The Forecaster was produced in 1915 as a portable forecaster which needed minimal instrumentation, a simple barometer and an observation of the wind direction, and was easy to calculate with.

[2] The original Zambretti algorithm has since been implemented in a number of electronic forecasters.