Walchensee wind: forecast and measurements
30 days of forecast vs. what actually happened at the lake. Click a single day to see its details.
Last 30 days
Rule-based forecast (actually used)
ML-based forecast — logistic (experimental)
ML-based forecast — HistGradientBoosting (black-box model, experimental)
Actual measurements (session ≥ 1 h)
Wed Sep 23
Thu Oct 22
session (≥ 1 h ≥ 11 kt)
marginal (≥ 1 h ≥ 8 kt)
no wind
no data
thunderstorm (forecast rows: predicted · actual row: observed)
Sep 26, 2026
avg wind
gust
ignition (8 kt)
session (11 kt)
For Sep 26, 2026 ·
as written at the time
MAYBE
Δ=-1.5 hPa — pressure gradient pushing against the thermal
🤖 ML — logistic
experimental
GO
GO 47% ·
MAYBE 35% ·
NO GO 18%
Strongest inputs —
(+) Bolzano pressure, dew-point spread, daytime cloud.
🤖 ML — HGB · black box
experimental
MAYBE
GO 41% ·
MAYBE 59% ·
NO GO 0%
Most distinctive inputs: morning solar, Innsbruck pressure, Bolzano pressure.
Experimental shadow models — they never drive the verdict.
How good are they? →
How the day was forecast at the time, before the rules were recalibrated — shown for comparison only.