One of the simplest weather tools one can operate is a barometer. I became interested in predicting the weather as my sailing interest grew a few years ago. I won't go into all the details of what can be determined by watching a barometer, but here are a couple of observations.
This morning, for example, I noticed that it had dropped two-tenths of an inch from where it was last night. A modest drop and one that indicates a minor decrease in nice weather was on its way.
Sure enough, it clouded up and began to snow this afternoon. When I reached home, it had dropped a further seven-tenths of an inch, indicating some unsettled weather, probably rain and a good blow. Two hours later, it is still dropping and we are now having a bit of a storm.
The useful observations are the direction (dropping or rising) and its speed (quickly or gradually). A list of forecasting tools can be found in The Complete Sailor on page 168.
E.F. Knight trusted his barometer implicitly and more than once credits observing it to having saved his life.
We once used it on the Severn River in Maryland to understand how the high pressure system was going to move around us and how we could use it to our advantage and have the wind blow us to our destination and back!
A very simple and useful tool.
