How fast does skill fall with lead time?
Planned · 15 November 2026
The question. The calibrations are fitted at day 0 and day 3 and the day-3 fit is used for days 4–7; how much skill is really left at each day, and should later days have their own fits?
Why
The site shows a week ahead, but every calibration has only been fitted at two leads. Using the day-3 fit beyond day 3 is an assumption, not a result.
Plan
The live archive keeps every 00z run to 192 h from 15 November 2026. Once a season of it exists, fit and score each calibration (frost, fog, thunder, wind) at each day 0–7 separately, and compare with applying the day-3 fit.
How it will be judged (fixed before running)
Cross-validated BSS by lead day. A separate fit for a day is adopted only where it beats the day-3 fit by at least 0.01 BSS; the lead at which skill falls to about zero will be stated on the site.