Barometer Pressure
We were recently asked why the barometer pressure on the site was different to that on the archives, so here is an explanation.
The Raw Barometer value in the archive is the raw pressure recorded by the weather station.
The Sea level pressure on the display is calculated.
Since pressure changes with height (and temperature...) all stations correct their raw pressure to sea-level pressure in order to compare.
This is about 0.125mb/m.
CWS is ~13m above sea level so the corrected pressure is currently raw pressure + 2mb.
We have now added the calculated sea level barometer to the archive report as a comparison.
// CWS