The original was designed for the Northern Hemisphere and UK 'Weather Range'. ie. The nearer the Poles the greater the spread between lower and upper barometer levels and large 'trends' are needed for weather conditions change. Conversely, the nearer the Equator the smaller the 'spread' and smaller 'trends' for change.
Hopefully I have correctly re-written the algorithm to allow for any location, and I have also increased 'wind direction' to 16 points to make it compatable with most wx kit.
A forecast at approx. 09:00 local Solar Time is allegedly better than 90% accurate ! - even though it takes no account of rate of barometer change, wind speed or temperature.
This code is free for all, including redistribution, as long as NO CHARGE is ever made for it's use or output.
beteljuice - June 2008