!Node.js CI

barometer-trend

Analyzes and calculates the tendency and trend of barometer readings over a one or three hour period including barometric weather predictions.

Features

- Tendency and trend of the barometer for the last hour or three hours (FALLING|SLOWLY)
- Prediction of weather and systems:
- By pressure trend only (Expect gale force weather')
- By pressure trend, thresholds and wind direction (Increasing rain, clearing within 12 hours.)
- By seasonal pressure thresholds for winter and summer (Cloudy and humid, thunderstorms)
- Front system tendency for the last three hours (Falling before a lesser rise | Cold front passage | Strong and gusty, then veers)
- Force wind expectation in Beaufort scale based on the pressure tendency (F8-9)
- Detects current pressure system Low, Normal, High

Note
- Picks the period with the highest severity (one hour or three hours)
- All calculations corrected (internally) to sea level pressure by optional altitude and temperature
- Up to 48 hour history

Install & Use

``
npm i barometer-trend
`

`
const barometer = require('barometer-trend');

barometer.addPressure(datetime1, 101500);
barometer.addPressure(datetime2, 101505);
barometer.addPressure(datetime3, 101512, 100, 20, 225); //100 = altitude, 20 = C degrees, 225 = wind direction

//barometer.addPressure(...) is more precise when pressure is corrected by altitude and temperature.

let forecast = barometer.getPredictions(); //returns JSON
`

Note


- Pressure must be input in Pascals, 1015 mBar/hPa = 101500 Pascal.
- getPredictions()` analyze the trend for the latest one hour and three hours. The one with the highest severity is returned.
- If run less than one hour or three hours, the latest timing up until now is picked.
- The most recent trend with the highest severity is chosen (One hour or Three hour reading)

Contribute

Feel free to contribute; create an Issue, and Pull Request including test code.

Disclaimer

- All calculations is done by online research; the author of this library does not have a background in metereology. All sources listed below.
- A barometer is only one source of weather information and may give a general trend and indication, but not "see" the overall picture. (There's a reason satelittes exists and being a metereologist is a paid job.)
- All calculations presumes being located at sea with no disturbances.
- Near land, winds may be one-two Beaufort scale numbers lower and the wind might be coming from "the wrong direction".
- In subtropic and tropical regions some of the calculations may not be valid at all; i.e. the trade winds (easterlies) is different from northern hemishpere west->east (westerlies) low pressure systems.
- In trade wind zones observe the daily variations; any change to this pattern could possibly indicate gale weather.

Sources / References

- How to use a barometer when sailing
- UK Met Office Marine Forecast Glossary
- Hughes38.com
- SafeBoater.com
- Air pressure changes and their meanings
- Sailing Eurybia
- Wikipedia: Beaufort scale
- Pressure conversion to sea level
- Heidorn.info: Applying The Barometer To Weather Watching