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)
Thu Aug 20
Fri Sep 18
session (≥ 1 h ≥ 11 kt)
marginal (≥ 1 h ≥ 8 kt)
no wind
no data
thunderstorm (forecast rows: predicted · actual row: observed)
Sep 8, 2026
avg wind
gust
ignition (8 kt)
session (11 kt)
For Sep 8, 2026 ·
as written at the time
GO
11 of 14 rules green.
⚡ Storm risk: the thermal often runs well until the front — watch the sky, come in early.
🤖 ML — logistic
experimental
MAYBE
GO 31% ·
MAYBE 46% ·
NO GO 23%
Strongest inputs —
(+) pressure Δ (thermik), daytime cloud; (−) dew-point spread.
🤖 ML — HGB · black box
experimental
MAYBE
GO 36% ·
MAYBE 39% ·
NO GO 25%
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.