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 9, 2026

81106:0021:0008:38 · avg 4.5 kt · gust 6.5 kt09:39 · avg 5.9 kt · gust 7.6 kt09:44 · avg 5.4 kt · gust 7.6 kt10:28 · avg 12.4 kt · gust 13.5 kt10:59 · avg 12.2 kt · gust 17.8 kt11:09 · avg 10.6 kt · gust 14.6 kt11:19 · avg 12.9 kt · gust 17.8 kt11:29 · avg 13.9 kt · gust 23.2 kt11:34 · avg 11.8 kt · gust 23.2 kt12:04 · avg 18.9 kt · gust 25.9 kt12:49 · avg 14.6 kt · gust 20.0 kt12:50 · avg 17.3 kt · gust 21.6 kt13:39 · avg 6.3 kt · gust 10.8 kt13:49 · avg 7.4 kt · gust 10.8 kt13:59 · avg 6.1 kt · gust 9.2 kt14:09 · avg 6.2 kt · gust 11.9 kt14:19 · avg 9.2 kt · gust 13.5 kt14:23 · avg 9.4 kt · gust 14.6 kt14:49 · avg 10.8 kt · gust 13.0 kt14:53 · avg 13.8 kt · gust 17.3 kt15:19 · avg 14.6 kt · gust 15.1 kt15:29 · avg 13.0 kt · gust 13.5 kt15:39 · avg 10.4 kt · gust 17.8 kt16:09 · avg 11.5 kt · gust 20.0 kt16:12 · avg 13.0 kt · gust 17.3 kt17:15 · avg 10.4 kt · gust 15.1 kt
avg wind gust ignition (8 kt) session (11 kt)
For Sep 9, 2026 · as written at the time

NO GO

100% daytime cloud + only 56 W/m² solar — no insolation to drive a thermal

⚡ Storm risk: the thermal often runs well until the front — watch the sky, come in early.

🤖 ML — logistic experimental NO GO GO 15% · MAYBE 14% · NO GO 71%

Strongest inputs — (+) dew-point spread; (−) morning solar, pressure Δ (thermik).

🤖 ML — HGB · black box experimental NO GO GO 0% · MAYBE 1% · NO GO 99%

Most distinctive inputs: morning solar, daytime cloud, Innsbruck pressure.

Experimental shadow models — they never drive the verdict. How good are they? →

Previous forecast method

How the day was forecast at the time, before the rules were recalibrated — shown for comparison only.