Barocast

Every barometer widget shows you a number and a line. Barocast tells you what the number means, and it does the one correction that makes the line trustworthy.

Air pressure has a daily rhythm of its own: a semidiurnal tide of about a hectopascal, peaking around ten in the morning and ten at night. Leave it in and every normal afternoon dip reads as bad weather coming. Barocast takes it out first, reduces to sea level with the hypsometric formula, and then runs Zambretti's forecaster on pressure, trend, wind direction and season.

WHAT IT DOES

• Corrected pressure as one big number with a trend arrow
• 24-hour graph from the watch's own pressure history
• A forecast in words, with a confidence
• Storm warning by vibration when the corrected fall passes 1.6 hPa an hour or 6 hPa in three
• The daily pressure tide removed, so the trend actually means something
• Altitude compensation, manual or from GPS
• hPa, inHg or mmHg, and the trend over 1, 3, 6 and 12 hours
• Five languages and a glance with pressure and arrow

WHAT IT NEEDS

• A watch with a barometer. Everything is worked out on the watch: no phone, no account, no internet