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

All stations (mean of daily station errors) · ECMWF IFS HRES · lead day 0

ALL · ifs_hres · lead 0

Target day = initialization date + 0 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not.

Scores use the latest model version segment, ifs-gpid161, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 2 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d25 2 QC3.22 [3.02, 3.39]0.40-2.74 [-2.98, -2.42]3.86 [3.68, 4.04]15% [11%, 21%]31%51%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d25 2 QC3.22 [2.96, 3.44]0.40-2.74 [-3.05, -2.31]3.86 [3.59, 4.11]15% [11%, 24%]31%51%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d25 2 QC3.22 [2.95, 3.49]0.40-2.74 [-3.06, -2.32]3.86 [3.59, 4.16]15% [11%, 23%]31%51%——2026-08-01 → 2026-08-30
tmax00Zbilinearall25 2 QC3.22 [2.95, 3.45]0.40-2.74 [-3.02, -2.31]3.86 [3.60, 4.13]15% [11%, 24%]31%51%——2026-08-01 → 2026-08-30
tmax00Znearest30d25 2 QC3.34 [3.19, 3.52]0.46-2.67 [-2.96, -2.32]4.10 [3.89, 4.34]17% [14%, 21%]32%51%——2026-08-01 → 2026-08-30
tmax00Znearest90d25 2 QC3.34 [3.13, 3.60]0.46-2.67 [-3.04, -2.21]4.10 [3.85, 4.44]17% [14%, 22%]32%51%——2026-08-01 → 2026-08-30
tmax00Znearest365d25 2 QC3.34 [3.13, 3.64]0.46-2.67 [-3.06, -2.19]4.10 [3.85, 4.50]17% [13%, 22%]32%51%——2026-08-01 → 2026-08-30
tmax00Znearestall25 2 QC3.34 [3.13, 3.60]0.46-2.67 [-3.01, -2.20]4.10 [3.85, 4.44]17% [14%, 22%]32%51%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d25 2 QC2.06 [1.91, 2.19]0.45+1.02 [0.74, 1.26]2.72 [2.50, 2.92]36% [32%, 39%]59%76%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d25 2 QC2.06 [1.91, 2.20]0.45+1.02 [0.67, 1.28]2.72 [2.49, 2.93]36% [31%, 38%]59%76%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d25 2 QC2.06 [1.90, 2.21]0.45+1.02 [0.67, 1.29]2.72 [2.49, 2.93]36% [31%, 39%]59%76%——2026-08-01 → 2026-08-30
tmin00Zbilinearall25 2 QC2.06 [1.89, 2.21]0.45+1.02 [0.61, 1.29]2.72 [2.48, 2.94]36% [30%, 39%]59%76%——2026-08-01 → 2026-08-30
tmin00Znearest30d25 2 QC2.21 [2.04, 2.36]0.48+1.12 [0.81, 1.39]2.94 [2.69, 3.17]33% [30%, 35%]57%72%——2026-08-01 → 2026-08-30
tmin00Znearest90d25 2 QC2.21 [2.04, 2.38]0.48+1.12 [0.73, 1.40]2.94 [2.68, 3.19]33% [29%, 35%]57%72%——2026-08-01 → 2026-08-30
tmin00Znearest365d25 2 QC2.21 [2.03, 2.38]0.48+1.12 [0.74, 1.40]2.94 [2.66, 3.18]33% [29%, 36%]57%72%——2026-08-01 → 2026-08-30
tmin00Znearestall25 2 QC2.21 [2.02, 2.38]0.48+1.12 [0.67, 1.40]2.94 [2.63, 3.20]33% [29%, 35%]57%72%——2026-08-01 → 2026-08-30

+ 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 error, last 90 days

Daily forecast minus observed error in °F for ECMWF IFS HRES at ALL, lead day 0, 00Z bilinear tmax+5+2.50-2.5-52026-08-01: -2.12 °F2026-08-06: -2.63 °F2026-08-08: -2.22 °F2026-08-09: -2.15 °F2026-08-10: -1.42 °F2026-08-11: -2.36 °F2026-08-12: -2.79 °F2026-08-13: -2.87 °F2026-08-14: -2.59 °F2026-08-15: -2.3 °F2026-08-16: -2.69 °F2026-08-17: -3.29 °F2026-08-18: -3.39 °F2026-08-19: -2.66 °F2026-08-20: -2.83 °F2026-08-21: -2.75 °F2026-08-22: -2.4 °F2026-08-23: -3.05 °F2026-08-24: -3.46 °F2026-08-25: -2.75 °F2026-08-26: -2.51 °F2026-08-27: -3.21 °F2026-08-28: -4.07 °F2026-08-29: -3.39 °F2026-08-30: -2.61 °F2026-08-012026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation. Hover a point for its date and value.
The same series as a table (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.61
2026-08-29-3.39
2026-08-28-4.07
2026-08-27-3.21
2026-08-26-2.51
2026-08-25-2.75
2026-08-24-3.46
2026-08-23-3.05
2026-08-22-2.40
2026-08-21-2.75
2026-08-20-2.83
2026-08-19-2.66
2026-08-18-3.39
2026-08-17-3.29
2026-08-16-2.69
2026-08-15-2.30
2026-08-14-2.59
2026-08-13-2.87
2026-08-12-2.79
2026-08-11-2.36
2026-08-10-1.42
2026-08-09-2.15
2026-08-08-2.22
2026-08-07—
2026-08-06-2.63
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02—
2026-08-01-2.12

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at ALL, lead day 0-5 to -4.5 °F: 0 days-4.5 to -4 °F: 1 day-4 to -3.5 °F: 0 days-3.5 to -3 °F: 6 days-3 to -2.5 °F: 11 days-2.5 to -2 °F: 6 days-2 to -1.5 °F: 0 days-1.5 to -1 °F: 1 day-1 to -0.5 °F: 0 days-0.5 to 0 °F: 0 days0 to 0.5 °F: 0 days0.5 to 1 °F: 0 days1 to 1.5 °F: 0 days1.5 to 2 °F: 0 days2 to 2.5 °F: 0 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 2.69 · P90 |e| 3.39 °F-50+5 °Fn = 25 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-5.00-4.500
-4.50-4.001
-4.00-3.500
-3.50-3.006
-3.00-2.5011
-2.50-2.006
-2.00-1.500
-1.50-1.001
-1.00-0.500
-0.50+0.000
+0.00+0.500
+0.50+1.000
+1.00+1.500
+1.50+2.000
+2.00+2.500
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08252.74 -2.74

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-01 → 2026-08-30 25
ECMWF IFS HRES2026-08-01 → 2026-08-30 25

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 25 -0.19 [-0.28, -0.07] yes
Aurora (GFS init) 2 -2.13 [-2.41, -1.84] yes
Aurora (IFS init) 3 -1.27 [-1.53, -0.76] yes
FourCastNet v2 (GFS init) 2 -0.69 [-0.85, -0.53] yes
FourCastNet v2 (IFS init) 3 -0.78 [-1.34, -0.27] yes
NCEP GFS 25 +0.57 [0.36, 0.73] yes
GraphCast (GFS init) 2 -1.93 [-2.20, -1.66] yes
GraphCast (IFS init) 23 -1.34 [-1.41, -1.22] yes
Pangu-Weather (GFS init) 2 -0.06 [-0.20, 0.08] no
Pangu-Weather (IFS init) 3 +0.19 [0.01, 0.54] yes

Cite this page

ShortCastCheck, ALL ifs_hres lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/ALL/model/ifs_hres/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: ALL (All stations (mean of daily station errors)), model ifs_hres, lead day 0. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/ALL/model/ifs_hres/lead/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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