Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

CastCheck methodology v0.2 · data through 2026-08-30

KTTN — Trenton Mercer

40.2764, -74.8164 · 64 m· standard offset UTC-5 h · truth product CLITTN

These pages are always bilinear interpolation, the headline method. The nearest-node variant, and every other window/initialization/interpolation/variable combination, is published on each permanent link below — follow any number.

Daily maximum temperature — MAE °F

the last 90 days, 12Z, bilinear. MAE with the bias and n underneath; every cell links to its permanent page. The sparkline shows the same model across lead days 1–9 on a scale shared within this table.
Modeld0d1d2d3d4d5d6d7d8d9lead 1–9
ECMWF AIFS Singleaifs_single 1.85+0.87 · n=29 2.05+0.18 · n=28 1.95+0.52 · n=27 1.80+0.66 · n=26 1.83+0.35 · n=24 2.50+0.30 · n=24 1.44+0.34 · n=23 2.22-0.76 · n=22 2.86-1.59 · n=21 ECMWF AIFS Single MAE by lead day 1 to 9, tmax
Aurora (GFS init)aurora_gfs 1.91-1.91 · n=2 2.93-2.93 · n=1 Aurora (GFS init) MAE by lead day 1 to 9, tmax
Aurora (IFS init)aurora_ifs 1.65-1.65 · n=2 1.04-1.04 · n=1 Aurora (IFS init) MAE by lead day 1 to 9, tmax
FourCastNet v2 (GFS init)fourcastnet_gfs 2.11+0.86 · n=2 1.78-1.78 · n=1 FourCastNet v2 (GFS init) MAE by lead day 1 to 9, tmax
FourCastNet v2 (IFS init)fourcastnet_ifs 2.39+0.21 · n=2 0.61-0.61 · n=1 FourCastNet v2 (IFS init) MAE by lead day 1 to 9, tmax
NCEP GFSgfs 2.73+0.71 · n=29 2.90-0.14 · n=28 2.85+0.40 · n=27 3.79-0.34 · n=26 3.52+1.20 · n=25 4.09+0.32 · n=24 5.12+1.43 · n=23 4.44+1.89 · n=22 5.83+1.68 · n=21 NCEP GFS MAE by lead day 1 to 9, tmax
GraphCast (GFS init)graphcast_gfs 0.91-0.91 · n=2 3.55-3.55 · n=1 GraphCast (GFS init) MAE by lead day 1 to 9, tmax
GraphCast (IFS init)graphcast_ifs 2.09-2.07 · n=27 2.58-2.36 · n=26 2.66-2.33 · n=25 2.50-1.47 · n=25 3.01-2.00 · n=25 2.40-1.52 · n=24 2.11-1.31 · n=23 3.87-2.54 · n=22 4.23-2.24 · n=21 GraphCast (IFS init) MAE by lead day 1 to 9, tmax
ECMWF IFS HRESifs_hres 2.07-0.66 · n=24 2.83-0.75 · n=22 2.75-0.58 · n=22 2.41+0.03 · n=21 2.91+0.33 · n=20 3.42+0.95 · n=19 3.88-1.41 · n=17 3.96-0.12 · n=17 5.16-1.28 · n=15 ECMWF IFS HRES MAE by lead day 1 to 9, tmax
Pangu-Weather (GFS init)pangu_gfs 2.76+2.76 · n=2 1.29+1.29 · n=1 Pangu-Weather (GFS init) MAE by lead day 1 to 9, tmax
Pangu-Weather (IFS init)pangu_ifs 2.57+2.57 · n=2 1.89+1.89 · n=1 Pangu-Weather (IFS init) MAE by lead day 1 to 9, tmax
Persistence (baseline)persistence 3.81-0.08 · n=90 5.37-0.10 · n=90 6.38-0.27 · n=90 6.46-0.30 · n=90 6.49-0.36 · n=90 6.50-0.30 · n=90 6.22-0.27 · n=90 6.62-0.36 · n=90 7.09-0.60 · n=90 Persistence (baseline) MAE by lead day 1 to 9, tmax

Up to 1 of the scored days in this table carry a QC flag on the observation (a CLI value that disagreed with the hourly observations, or a fallback source). They are kept in the scores and counted here rather than dropped — see methodology.

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily minimum temperature — MAE °F

the last 90 days, 12Z, bilinear. MAE with the bias and n underneath; every cell links to its permanent page. The sparkline shows the same model across lead days 1–9 on a scale shared within this table.
Modeld0d1d2d3d4d5d6d7d8d9lead 1–9
ECMWF AIFS Singleaifs_single 4.11+4.11 · n=29 4.49+4.49 · n=28 4.52+4.52 · n=27 4.01+3.93 · n=26 3.87+3.72 · n=24 4.03+3.76 · n=24 4.24+4.02 · n=23 4.34+4.34 · n=22 4.05+3.84 · n=21 ECMWF AIFS Single MAE by lead day 1 to 9, tmin
Aurora (GFS init)aurora_gfs 5.60+5.60 · n=2 6.91+6.91 · n=1 Aurora (GFS init) MAE by lead day 1 to 9, tmin
Aurora (IFS init)aurora_ifs 3.52+3.52 · n=2 4.25+4.25 · n=1 Aurora (IFS init) MAE by lead day 1 to 9, tmin
FourCastNet v2 (GFS init)fourcastnet_gfs 8.43+8.43 · n=2 11.68+11.68 · n=1 FourCastNet v2 (GFS init) MAE by lead day 1 to 9, tmin
FourCastNet v2 (IFS init)fourcastnet_ifs 7.44+7.44 · n=2 10.54+10.54 · n=1 FourCastNet v2 (IFS init) MAE by lead day 1 to 9, tmin
NCEP GFSgfs 3.13+3.12 · n=29 3.27+3.00 · n=28 3.86+3.65 · n=27 3.64+3.19 · n=26 4.24+2.81 · n=25 4.74+3.24 · n=24 5.25+3.85 · n=23 5.35+3.52 · n=22 5.31+3.05 · n=21 NCEP GFS MAE by lead day 1 to 9, tmin
GraphCast (GFS init)graphcast_gfs 6.37+6.37 · n=2 8.45+8.45 · n=1 GraphCast (GFS init) MAE by lead day 1 to 9, tmin
GraphCast (IFS init)graphcast_ifs 3.34+3.34 · n=27 3.52+3.50 · n=26 3.55+3.55 · n=25 3.66+3.66 · n=25 3.91+3.64 · n=25 4.30+3.80 · n=24 4.07+3.94 · n=23 4.82+4.14 · n=22 3.89+2.77 · n=21 GraphCast (IFS init) MAE by lead day 1 to 9, tmin
ECMWF IFS HRESifs_hres 3.64+3.64 · n=24 4.04+3.86 · n=22 4.09+4.09 · n=22 4.28+4.11 · n=21 3.98+3.91 · n=20 4.45+4.30 · n=19 4.61+4.61 · n=17 5.95+5.41 · n=17 4.89+4.16 · n=15 ECMWF IFS HRES MAE by lead day 1 to 9, tmin
Pangu-Weather (GFS init)pangu_gfs 6.45+6.45 · n=2 7.93+7.93 · n=1 Pangu-Weather (GFS init) MAE by lead day 1 to 9, tmin
Pangu-Weather (IFS init)pangu_ifs 6.18+6.18 · n=2 7.92+7.92 · n=1 Pangu-Weather (IFS init) MAE by lead day 1 to 9, tmin
Persistence (baseline)persistence 3.72-0.08 · n=90 5.36-0.24 · n=90 5.88-0.43 · n=90 5.57-0.59 · n=90 5.37-0.61 · n=90 5.36-0.56 · n=90 5.62-0.56 · n=90 5.92-0.63 · n=90 6.24-0.80 · n=90 Persistence (baseline) MAE by lead day 1 to 9, tmin

Up to 1 of the scored days in this table carry a QC flag on the observation (a CLI value that disagreed with the hourly observations, or a fallback source). They are kept in the scores and counted here rather than dropped — see methodology.

Month-by-month slices, model availability and the observed-truth table live on the canonical page: they do not depend on the window, initialization or interpolation selected here.

All scores as JSON scores_latest.csv daily_errors.csv.gz data & licences