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 · `v2026-08-02_133103_wave_height_lgb`

Quantile-LGB (q05/q50/q95) over the five wave models, split-CQR calibrated to a 90% band. Trained 2026-08-02 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	31,142 / 3,893 / 3,893
Training window	2022-01-01 → 2026-06-10
Features	51

Buoy verify history (15 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	≤168h
Mon 2026-08-03	`v2026-07-26_133509_wave_height_lgb` `v2026-08-02_133103_wave_height_lgb`	156	0.079 cov 0.58	0.135 cov 0.40	0.126 cov 0.51	0.189 cov 0.40	0.185 cov 0.49	0.244 cov 0.28	0.334 cov 0.00
Thu 2026-07-30	`v2026-07-19_132405_wave_height_lgb` `v2026-07-26_133509_wave_height_lgb`	155	0.126 cov 0.60	0.133 cov 0.50	0.129 cov 0.72	0.159 cov 0.50	0.274 cov 0.45	0.205 cov 0.52	0.152 cov 0.80
Mon 2026-07-27	`v2026-07-19_132405_wave_height_lgb` `v2026-07-26_133509_wave_height_lgb`	156	0.158 cov 0.50	0.253 cov 0.33	0.281 cov 0.36	0.367 cov 0.39	0.394 cov 0.20	0.255 cov 0.47	0.163 cov 1.00
Thu 2026-07-23	`v2026-07-12_132947_wave_height_lgb` `v2026-07-19_132405_wave_height_lgb`	156	0.202 cov 0.23	0.216 cov 0.35	0.287 cov 0.36	0.415 cov 0.17	0.365 cov 0.15	0.324 cov 0.19	0.272 cov 0.33
Mon 2026-07-20	`v2026-07-12_132947_wave_height_lgb` `v2026-07-19_132405_wave_height_lgb`	156	0.235 cov 0.08	0.294 cov 0.15	0.271 cov 0.19	0.374 cov 0.15	0.333 cov 0.21	0.269 cov 0.32	0.202 cov 0.50
Thu 2026-07-16	`v2026-07-05_132623_wave_height_lgb` `v2026-07-12_132947_wave_height_lgb`	156	0.343 cov 0.21	0.300 cov 0.20	0.194 cov 0.33	0.303 cov 0.17	0.317 cov 0.37	0.328 cov 0.45	0.180 cov 0.60
Mon 2026-07-13	`v2026-07-05_132623_wave_height_lgb` `v2026-07-12_132947_wave_height_lgb`	156	0.722 cov 0.25	0.140 cov 0.64	0.138 cov 0.68	0.196 cov 0.52	0.302 cov 0.33	0.393 cov 0.45	0.308 cov 0.33
Thu 2026-07-09	`v2026-06-28_133826_wave_height_lgb` `v2026-07-05_132623_wave_height_lgb`	155	0.097 cov 0.58	0.077 cov 0.72	0.077 cov 0.67	0.099 cov 0.75	0.195 cov 0.51	0.191 cov 0.55	0.177 cov 0.60
Mon 2026-07-06	`v2026-06-28_133826_wave_height_lgb` `v2026-07-05_132623_wave_height_lgb`	155	0.137 cov 0.58	0.182 cov 0.59	0.149 cov 0.68	0.139 cov 0.80	0.134 cov 0.80	0.106 cov 0.78	0.157 cov 0.67
Thu 2026-07-02	`v2026-06-21_133630_wave_height_lgb` `v2026-06-28_133826_wave_height_lgb`	156	0.388 cov 0.26	0.248 cov 0.50	0.184 cov 0.64	0.206 cov 0.67	0.486 cov 0.22	0.463 cov 0.31	0.619 cov 0.00
Mon 2026-06-29	`v2026-06-21_133630_wave_height_lgb` `v2026-06-28_133826_wave_height_lgb`	155	0.729 cov 0.00	0.362 cov 0.10	0.440 cov 0.02	0.462 cov 0.18	0.550 cov 0.15	0.598 cov 0.15	0.831 cov 0.00
Thu 2026-06-25	`v2026-06-14_133129_wave_height_lgb` `v2026-06-21_133630_wave_height_lgb`	154	0.315 cov 0.08	0.313 cov 0.00	0.424 cov 0.00	0.769 cov 0.00	0.321 cov 0.20	0.387 cov 0.07	0.455 cov 0.07
Mon 2026-06-22	`v2026-06-14_133129_wave_height_lgb` `v2026-06-21_133630_wave_height_lgb`	155	0.412 cov 0.00	0.218 cov 0.29	0.207 cov 0.33	0.227 cov 0.30	0.244 cov 0.28	0.314 cov 0.03	0.438 cov 0.00
Thu 2026-06-18	`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	—
Mon 2026-06-15	`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	—	—	—	—