ADE WS 1911 Mode D'emploi page 74

heavy rain/thunderstorm
In conjunction with the air pressure trend, further weather
interpretations are possible.
rising air pressure
constant air pressure
falling air pressure
Two examples:
‚ Weather forecast shows rain, the air pressure is falling
off quickly and steeply >> strong rain is probable.
‚ Weather forecast shows rain, the air pressure has risen
in the last 12 hours but in the last 3 hours as fallen off
somewhat >> light rain is probable.
74
snowfall
WS 1911 weather station