Pattern Warning
A look forward rather than back: once Cairn has enough history, it learns what tends to come before your harder days and tells you in the morning when today looks like one of them.
How it differs from pattern alerts
Pattern alerts name something that has already repeated — a person or a theme that keeps coming up. Pattern Warning looks the other way, at the day ahead. It trains on your own history: the HRV range you sit in before a rough day, runs of low entries, and the weekdays and hours that have tended to go worse for you than the rest.
Locked until it has enough to work with
The model needs around 45 days of analysed entries before it will train, and the screen shows how far along you are. After that you switch on morning warnings yourself — nothing happens until you ask for it — and Cairn runs one check in the morning. At most one warning a day, and if you already use the morning and evening ritual reminders, those take precedence and no warning is added on top.
Tell it when it was wrong
Every warning asks whether the prediction was accurate, and both answers are useful. The historical pattern match shown next to the model is how well it fits your past entries, not a promise about tomorrow. You can retrain it whenever you have more history, and the last few warnings stay on the screen so you can see how it has been doing.