WeatherBlend

Multi-model forecast blending for Sennen, Cornwall

Sea state models

Significant wave height — quantile-LGB over the five wave models with a conformal-calibrated (CQR) 90% band. Hs MAE in metres, lower better; band coverage nominal 0.90.

Significant wave height — Sennen marine cell

Phase wave_height_lgb · v2026-06-14_133129_wave_height_lgb

Quantile-LGB (q05/q50/q95) over the five wave models, split-CQR calibrated to a 90% band. Trained 2026-06-14 on era5_ocean reanalysis (training truth; the Sevenstones buoy is the verification truth below). Trained on lead-unlabelled hindcast; per-lead calibration planned once the offset_day archive matures (~2026-09).

Hs MAE (cal slice, vs era5_ocean) 0.108 m
90% band coverage (cal slice) 0.901 (nominal 0.90)
Training / val / cal rows 31,104 / 3,888 / 3,888
Training window 2022-01-01 → 2026-06-08
Features 51
Buoy verify history (2 runs)

Mon + Thu rolling Hs MAE (m) + empirical 90%-band coverage vs the Sevenstones Light Vessel buoy, per 24h actual-lead bucket (≤24h = leads 0-23h, …). The buoy sits ~28 km W of the forecast cell, so absolute MAE carries a location mismatch — read the trend, not the level. Red cells flag drift: band coverage well below the nominal 0.90 (MAE is never a drift trigger here, for the same location-mismatch reason).

Run (UTC) Version N ≤24h≤48h≤72h≤96h≤120h≤144h
v2026-06-11_232802_wave_height_lgb
v2026-06-14_133129_wave_height_lgb		 84 0.200
cov 0.36		0.199
cov 0.45		0.214
cov 0.53		0.157
cov 0.75		0.250
cov 0.53		0.170
cov 0.75
v2026-06-11_232802_wave_height_lgb
v2026-06-14_133129_wave_height_lgb		 36 0.202
cov 0.33		0.245
cov 0.42		0.286
cov 0.17		———