WeatherBlend

Multi-model forecast blending for Membury, East Devon

Temperature models

2b (lean) + 2c (rich). MAE °C, lower better. Δ vs best single NWP — negative = blend wins.

Temperature — Membury Devon

Phase 2c · `v2026-06-15_085319_phase2c` Δ +0.000 vs prev train

Rich blender, 88 features (adds dew/RH/cloud/wind/pressure). Trained 2026-06-15. Metric: Test MAE (°C).

Lead	Blend	Best single	Δ vs best
+24h	0.491	temp_ecmwf (0.903)	-45.6%
+48h	0.583	temp_aifs (0.720)	-19.1%
+72h	0.693	temp_aifs (0.813)	-14.7%
+96h	0.856	temp_aifs (0.958)	-10.6%
+120h	1.072	temp_aifs (1.091)	-1.7%

Verify history (9 runs)

Mon + Thu rolling MAE (°C). Per-lead cells turn red when the rolling metric breaches the lead-specific drift threshold; check the verify report for the per-cell breakdown. Version column names the trained model — a fresh champion takes ~5-9d to show.

Run (UTC)	Version	N	+24h	+48h	+72h	+96h	+120h
Thu 2026-06-18	`v2026-06-01_234001_phase2c` `v2026-06-07_143923_phase2c`	528	0.398 temp_ecmwf: 0.522	0.413 temp_ecmwf: 0.570	0.486 temp_aifs: 0.496	1.143 temp_ukmo: 0.688	0.649 temp_aifs: 0.687
Mon 2026-06-15	`v2026-06-01_234001_phase2c` `v2026-06-07_143923_phase2c`	528	0.474 temp_aifs: 0.533	0.494 temp_aifs: 0.516	0.488 temp_ecmwf: 0.710	0.634 temp_ecmwf: 0.796	0.625 temp_ecmwf: 0.698
Fri 2026-06-12	`v2026-06-01_234001_phase2c`	432	0.351 temp_aifs: 0.493	0.577 temp_aifs: 0.523	0.559 temp_aifs: 0.813	0.691 temp_mf: 0.781	0.705 temp_aifs: 0.808
Thu 2026-06-11	`v2026-05-26_102733_phase2c` `v2026-06-01_234001_phase2c`	528	0.321 temp_aifs: 0.501	0.347 temp_aifs: 0.445	0.652 temp_aifs: 0.350	0.612 temp_aifs: 0.797	0.686 temp_aifs: 0.750
Mon 2026-06-08	`v2026-05-26_102733_phase2c` `v2026-05-31_210744_phase2c`	528	0.312 temp_aifs: 0.571	0.563 temp_icon: 0.989	0.715 temp_gem: 0.922	0.654 temp_aifs: 0.870	0.706 temp_aifs: 0.796
Thu 2026-06-04	`v2026-05-17_173719_phase2c` `v2026-05-24_141820_phase2c` `v2026-05-26_102733_phase2c`	744	0.989 temp_icon: 1.029	0.781 temp_icon: 1.067	1.293 temp_aifs: 1.358	0.990 temp_aifs: 1.408	1.689 temp_aifs: 1.855
Mon 2026-06-01	`v2026-05-17_173719_phase2c` `v2026-05-24_141820_phase2c`	744	0.983 temp_gem: 1.060	0.957 temp_icon: 0.615	1.021 temp_icon: 1.136	1.454 temp_icon: 1.929	1.589 temp_aifs: 1.843
Thu 2026-05-28	`v2026-05-14_220930_phase2c` `v2026-05-17_173719_phase2c`	432	0.474 temp_aifs: 0.507	0.515 temp_aifs: 0.611	0.787 temp_ukmo: 0.697	0.508 temp_gem: 0.683	0.544 temp_aifs: 0.680
Mon 2026-05-25	`v2026-05-14_220930_phase2c` `v2026-05-17_173719_phase2c`	240	0.663 temp_ecmwf: 0.379	0.636 temp_gem: 0.563	0.797 temp_ecmwf: 0.490	—	—

By actual NWP forecast lead (6h buckets)

Same data grouped by ValidTime − freshest contributing NWP cycle (6h buckets) instead of trained-lead label. Reveals MAE structure within a trained bucket once predict spread to hourly outputs (2026-05-04+). Buckets start at the trained lead — earlier figures measured from the cron-fire time, which made offset-day models look like sub-lead forecasts.

Run (UTC)	0-5h	6-11h	12-17h	18-23h	24-29h	30-35h	36-41h	42-47h	48-53h	54-59h	60-65h	66-71h	72-77h	78-83h	84-89h	90-95h	96-101h	102-107h	108-113h	114-119h	120-125h	126-131h	132-137h	138-143h
Thu 2026-06-18	—	—	—	—	0.407	0.360	0.404	0.367	0.418	0.445	0.371	0.258	0.413	0.580	0.859	1.079	1.108	1.522	0.675	0.665	0.595	0.643	0.802	1.243
Mon 2026-06-15	—	—	—	—	0.485	0.351	0.368	0.257	0.424	0.646	0.692	0.577	0.440	0.597	0.641	0.511	0.592	0.640	0.856	0.824	0.619	0.572	0.668	0.845
Fri 2026-06-12	—	—	—	—	0.341	0.372	0.392	0.332	0.485	0.782	0.878	0.701	0.506	0.680	0.699	0.771	0.554	0.881	1.301	1.491	0.705	0.626	0.743	0.608
Thu 2026-06-11	—	—	—	—	0.341	0.320	0.255	0.101	0.349	0.452	0.221	0.183	0.652	0.395	0.645	0.434	0.628	0.537	0.673	0.450	0.696	0.626	0.743	0.608
Mon 2026-06-08	—	—	—	—	0.312	0.100	0.576	0.201	0.565	0.557	0.593	0.454	0.740	0.625	0.748	0.456	0.704	0.457	0.672	0.278	0.769	0.526	0.506	0.263
Thu 2026-06-04	—	—	—	—	1.053	0.915	0.673	0.119	0.786	0.742	0.929	0.827	1.320	1.085	1.698	0.573	1.055	0.279	1.498	1.113	1.487	2.063	2.483	1.609
Mon 2026-06-01	1.660	1.307	1.188	0.936	0.798	0.807	0.904	1.026	0.423	0.286	0.918	1.018	1.144	1.380	1.411	1.449	1.079	1.331	1.393	1.474	1.660	2.354	2.025	1.871
Thu 2026-05-28	0.203	0.251	0.476	0.496	0.421	0.587	0.449	0.508	0.521	0.667	0.769	0.895	0.855	0.798	0.796	0.674	0.481	0.202	0.649	0.584	0.552	0.512	0.400	0.548
Mon 2026-05-25	0.254	0.523	1.397	0.440	0.487	0.428	0.478	0.594	0.595	0.793	0.871	0.558	0.644	1.280	0.738	1.260	—	—	—	—	—	—	—	—

Phase 2b · `v2026-06-14_151908` Δ -0.015 vs prev train

Lean blender, 13 features. Trained 2026-06-14. Metric: Test MAE (°C).

Lead	Blend	Best single	Δ vs best
+24h	0.525	temp_ecmwf (0.903)	-41.8%
+48h	0.597	temp_aifs (0.720)	-17.0%
+72h	0.718	temp_aifs (0.813)	-11.7%
+96h	0.876	temp_aifs (0.958)	-8.6%
+120h	1.067	temp_aifs (1.091)	-2.2%

Verify history (9 runs)

Run (UTC)	Version	N	+24h	+48h	+72h	+96h	+120h
Thu 2026-06-18	`v2026-06-05_091951` `v2026-06-07_143856`	384	0.408 temp_ecmwf: 0.522	0.440 temp_ecmwf: 0.570	0.457 temp_aifs: 0.496	1.105 temp_gfs: 0.821	0.665 temp_aifs: 0.632
Mon 2026-06-15	`v2026-05-26_102714` `v2026-06-05_091951` `v2026-06-07_143856`	320	0.473 temp_aifs: 0.533	0.332 temp_icon: 0.502	0.496 temp_aifs: 0.617	0.504 temp_ecmwf: 0.630	0.556 temp_icon: 0.693
Fri 2026-06-12	`v2026-05-26_102714` `v2026-05-31_210717` `v2026-06-05_091951`	528	0.406 temp_icon: 0.400	0.446 temp_mf: 0.551	0.369 temp_aifs: 0.713	0.602 temp_aifs: 0.797	0.638 temp_aifs: 0.750
Thu 2026-06-11	`v2026-05-26_102714` `v2026-05-31_210717`	528	0.429 temp_icon: 0.493	0.446 temp_mf: 0.551	0.369 temp_aifs: 0.713	0.602 temp_aifs: 0.797	0.638 temp_aifs: 0.750
Mon 2026-06-08	`v2026-05-26_102714` `v2026-05-31_210717`	528	0.341 temp_aifs: 0.571	0.613 temp_icon: 0.989	0.626 temp_gem: 0.922	0.647 temp_aifs: 0.870	0.765 temp_aifs: 0.796
Thu 2026-06-04	`v2026-05-17_173539` `v2026-05-24_141800` `v2026-05-26_102714`	744	0.900 temp_icon: 1.029	0.871 temp_icon: 1.067	1.116 temp_aifs: 1.358	0.893 temp_aifs: 1.408	1.904 temp_aifs: 1.855
Mon 2026-06-01	`v2026-05-17_173539` `v2026-05-24_141800`	744	1.068 temp_gem: 1.060	0.975 temp_icon: 0.615	1.171 temp_icon: 1.136	1.539 temp_icon: 1.929	1.838 temp_aifs: 1.843
Thu 2026-05-28	`v2026-05-14_220359` `v2026-05-17_173539`	432	0.434 temp_aifs: 0.507	0.569 temp_aifs: 0.611	0.784 temp_aifs: 0.788	0.668 temp_gem: 0.683	0.634 temp_aifs: 0.680
Mon 2026-05-25	`v2026-05-14_220359` `v2026-05-17_173539`	240	0.705 temp_ecmwf: 0.379	0.540 temp_gem: 0.563	0.821 temp_ecmwf: 0.490	—	—

By actual NWP forecast lead (6h buckets)

Run (UTC)	0-5h	6-11h	12-17h	18-23h	24-29h	30-35h	36-41h	42-47h	48-53h	54-59h	60-65h	66-71h	72-77h	78-83h	84-89h	90-95h	96-101h	102-107h	108-113h	114-119h	120-125h	126-131h	132-137h	138-143h
Thu 2026-06-18	—	—	—	—	0.425	0.356	0.403	0.327	0.450	0.452	0.398	0.284	0.368	0.563	0.866	1.356	1.088	1.286	0.602	0.733	0.602	0.607	0.929	2.066
Mon 2026-06-15	—	—	—	—	0.510	0.068	0.456	0.097	0.298	0.476	0.398	0.254	0.487	0.606	0.344	0.272	0.446	0.564	0.729	0.579	0.540	0.544	0.743	0.440
Fri 2026-06-12	—	—	—	—	0.352	0.577	0.758	0.250	0.426	0.575	0.555	0.346	0.369	0.447	0.586	0.349	0.604	0.558	0.729	0.471	0.656	0.539	0.743	0.440
Thu 2026-06-11	—	—	—	—	0.386	0.625	0.616	0.250	0.426	0.575	0.555	0.346	0.369	0.447	0.586	0.349	0.604	0.558	0.729	0.471	0.656	0.539	0.743	0.440
Mon 2026-06-08	—	—	—	—	0.341	0.194	0.557	0.257	0.643	0.566	0.520	0.342	0.662	0.514	0.612	0.342	0.678	0.480	0.802	0.347	0.827	0.544	0.618	0.443
Thu 2026-06-04	—	—	—	—	0.927	0.975	0.629	0.245	0.870	0.878	0.782	0.299	1.189	0.787	1.330	0.216	0.957	0.188	1.608	1.227	1.690	2.352	2.610	1.930
Mon 2026-06-01	1.597	1.276	1.302	1.060	0.897	0.937	0.901	1.010	0.461	0.442	1.031	1.175	1.259	1.477	1.496	1.645	1.189	1.422	1.594	1.713	1.966	2.640	2.171	1.890
Thu 2026-05-28	0.180	0.225	0.473	0.430	0.404	0.535	0.529	0.592	0.539	0.633	0.758	0.916	0.861	0.821	0.891	0.820	0.088	0.293	0.701	0.651	0.668	0.665	0.571	0.604
Mon 2026-05-25	0.278	0.537	1.515	0.457	0.482	0.329	0.508	0.509	0.460	0.633	0.812	0.604	0.666	1.134	0.960	1.149	—	—	—	—	—	—	—	—