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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 8

ALL · ifs_hres · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d17 2 QC4.31 [3.79, 4.72]0.73-2.61 [-2.96, -2.00]5.46 [4.81, 6.02]15% [12%, 18%]28%41%+0.03+0.442026-08-09 → 2026-08-30
tmax00Zbilinear90d17 2 QC4.31 [3.54, 4.74]0.73-2.61 [-3.00, -1.83]5.46 [4.64, 6.05]15% [13%, 20%]28%41%+0.03+0.442026-08-09 → 2026-08-30
tmax00Zbilinear365d17 2 QC4.31 [3.42, 4.77]0.73-2.61 [-3.01, -1.81]5.46 [4.62, 6.11]15% [12%, 20%]28%41%+0.03+0.442026-08-09 → 2026-08-30
tmax00Zbilinearall17 2 QC4.31 [3.66, 4.73]0.73-2.61 [-3.00, -1.83]5.46 [4.71, 6.04]15% [12%, 19%]28%41%+0.03+0.442026-08-09 → 2026-08-30
tmax00Znearest30d17 2 QC4.52 [4.01, 4.93]0.74-2.61 [-2.93, -1.94]5.77 [5.11, 6.31]14% [12%, 17%]27%40%-0.02+0.432026-08-09 → 2026-08-30
tmax00Znearest90d17 2 QC4.52 [3.79, 4.94]0.74-2.61 [-2.97, -1.75]5.77 [4.90, 6.34]14% [13%, 18%]27%40%-0.02+0.432026-08-09 → 2026-08-30
tmax00Znearest365d17 2 QC4.52 [3.77, 4.97]0.74-2.61 [-2.97, -1.72]5.77 [4.87, 6.38]14% [12%, 20%]27%40%-0.02+0.432026-08-09 → 2026-08-30
tmax00Znearestall17 2 QC4.52 [3.85, 4.93]0.74-2.61 [-2.97, -1.73]5.77 [4.92, 6.31]14% [12%, 20%]27%40%-0.02+0.432026-08-09 → 2026-08-30
tmax12Zbilinear30d17 2 QC4.21 [3.81, 4.56]1.14-3.02 [-3.53, -2.39]5.21 [4.71, 5.57]12% [10%, 17%]26%40%+0.05+0.132026-08-09 → 2026-08-30
tmax12Zbilinear90d17 2 QC4.21 [3.74, 4.54]1.14-3.02 [-3.58, -2.30]5.21 [4.50, 5.56]12% [10%, 22%]26%40%+0.05+0.132026-08-09 → 2026-08-30
tmax12Zbilinear365d17 2 QC4.21 [3.73, 4.59]1.14-3.02 [-3.59, -2.29]5.21 [4.50, 5.63]12% [9%, 22%]26%40%+0.05+0.132026-08-09 → 2026-08-30
tmax12Zbilinearall17 2 QC4.21 [3.73, 4.57]1.14-3.02 [-3.59, -2.30]5.21 [4.50, 5.60]12% [9%, 21%]26%40%+0.05+0.132026-08-09 → 2026-08-30
tmax12Znearest30d17 2 QC4.42 [4.04, 4.72]1.14-3.08 [-3.58, -2.44]5.47 [4.97, 5.81]11% [9%, 15%]25%39%+0.00+0.132026-08-09 → 2026-08-30
tmax12Znearest90d17 2 QC4.42 [3.85, 4.70]1.14-3.08 [-3.62, -2.35]5.47 [4.71, 5.80]11% [9%, 17%]25%39%+0.00+0.132026-08-09 → 2026-08-30
tmax12Znearest365d17 2 QC4.42 [3.85, 4.74]1.14-3.08 [-3.65, -2.31]5.47 [4.71, 5.88]11% [9%, 17%]25%39%+0.00+0.132026-08-09 → 2026-08-30
tmax12Znearestall17 2 QC4.42 [3.89, 4.73]1.14-3.08 [-3.64, -2.34]5.47 [4.71, 5.83]11% [9%, 17%]25%39%+0.00+0.132026-08-09 → 2026-08-30
tmin00Zbilinear30d17 2 QC3.47 [3.12, 3.75]0.88+1.85 [1.59, 2.14]4.51 [4.11, 4.82]19% [16%, 22%]38%53%+0.07+0.062026-08-09 → 2026-08-30
tmin00Zbilinear90d17 2 QC3.47 [3.11, 3.77]0.88+1.85 [1.57, 2.15]4.51 [4.08, 4.84]19% [15%, 22%]38%53%+0.07+0.062026-08-09 → 2026-08-30
tmin00Zbilinear365d17 2 QC3.47 [3.04, 3.76]0.88+1.85 [1.55, 2.21]4.51 [4.04, 4.82]19% [15%, 23%]38%53%+0.07+0.062026-08-09 → 2026-08-30
tmin00Zbilinearall17 2 QC3.47 [3.04, 3.82]0.88+1.85 [1.54, 2.17]4.51 [4.06, 4.87]19% [15%, 23%]38%53%+0.07+0.062026-08-09 → 2026-08-30
tmin00Znearest30d17 2 QC3.66 [3.25, 3.96]0.87+1.86 [1.60, 2.16]4.74 [4.30, 5.07]20% [14%, 28%]35%52%+0.02+0.072026-08-09 → 2026-08-30
tmin00Znearest90d17 2 QC3.66 [3.22, 4.00]0.87+1.86 [1.58, 2.22]4.74 [4.27, 5.09]20% [12%, 30%]35%52%+0.02+0.072026-08-09 → 2026-08-30
tmin00Znearest365d17 2 QC3.66 [3.14, 4.00]0.87+1.86 [1.58, 2.25]4.74 [4.20, 5.08]20% [12%, 30%]35%52%+0.02+0.072026-08-09 → 2026-08-30
tmin00Znearestall17 2 QC3.66 [3.13, 4.06]0.87+1.86 [1.58, 2.22]4.74 [4.22, 5.11]20% [11%, 30%]35%52%+0.02+0.072026-08-09 → 2026-08-30
tmin12Zbilinear30d17 2 QC3.31 [2.96, 3.60]0.98+1.75 [1.38, 2.21]4.31 [3.91, 4.66]24% [20%, 26%]41%56%+0.12-0.052026-08-09 → 2026-08-30
tmin12Zbilinear90d17 2 QC3.31 [2.91, 3.66]0.98+1.75 [1.35, 2.58]4.31 [3.85, 4.72]24% [19%, 26%]41%56%+0.12-0.052026-08-09 → 2026-08-30
tmin12Zbilinear365d17 2 QC3.31 [2.86, 3.61]0.98+1.75 [1.38, 2.58]4.31 [3.79, 4.70]24% [20%, 26%]41%56%+0.12-0.052026-08-09 → 2026-08-30
tmin12Zbilinearall17 2 QC3.31 [2.87, 3.66]0.98+1.75 [1.34, 2.46]4.31 [3.79, 4.73]24% [19%, 26%]41%56%+0.12-0.052026-08-09 → 2026-08-30
tmin12Znearest30d17 2 QC3.47 [3.08, 3.77]1.01+1.76 [1.38, 2.22]4.54 [4.08, 4.91]20% [18%, 23%]39%54%+0.07-0.092026-08-09 → 2026-08-30
tmin12Znearest90d17 2 QC3.47 [3.02, 3.82]1.01+1.76 [1.36, 2.59]4.54 [4.02, 4.98]20% [18%, 25%]39%54%+0.07-0.092026-08-09 → 2026-08-30
tmin12Znearest365d17 2 QC3.47 [2.98, 3.79]1.01+1.76 [1.42, 2.67]4.54 [3.94, 4.91]20% [18%, 26%]39%54%+0.07-0.092026-08-09 → 2026-08-30
tmin12Znearestall17 2 QC3.47 [3.02, 3.83]1.01+1.76 [1.36, 2.53]4.54 [3.95, 5.00]20% [18%, 25%]39%54%+0.07-0.092026-08-09 → 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 8, 00Z bilinear tmax+5+2.50-2.5-52026-08-09: -2.75 °F2026-08-15: -0.49 °F2026-08-16: -2.69 °F2026-08-17: -2.65 °F2026-08-18: -2.66 °F2026-08-19: -3.5 °F2026-08-20: -2.83 °F2026-08-21: -3.2 °F2026-08-22: -2.79 °F2026-08-23: -2.75 °F2026-08-24: -4.09 °F2026-08-25: -2.02 °F2026-08-26: -2.69 °F2026-08-27: -3.03 °F2026-08-28: -4.52 °F2026-08-29: -0.49 °F2026-08-30: -1.26 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.26
2026-08-29-0.49
2026-08-28-4.52
2026-08-27-3.03
2026-08-26-2.69
2026-08-25-2.02
2026-08-24-4.09
2026-08-23-2.75
2026-08-22-2.79
2026-08-21-3.20
2026-08-20-2.83
2026-08-19-3.50
2026-08-18-2.66
2026-08-17-2.65
2026-08-16-2.69
2026-08-15-0.49
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09-2.75

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at ALL, lead day 8-5 to -4.5 °F: 1 day-4.5 to -4 °F: 1 day-4 to -3.5 °F: 0 days-3.5 to -3 °F: 3 days-3 to -2.5 °F: 8 days-2.5 to -2 °F: 1 day-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: 2 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| 2.75 · P90 |e| 3.74 °F-50+5 °Fn = 17 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
-5.00-4.501
-4.50-4.001
-4.00-3.500
-3.50-3.003
-3.00-2.508
-2.50-2.001
-2.00-1.500
-1.50-1.001
-1.00-0.500
-0.50+0.002
+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
2026-08172.61 -2.61

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17

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 17 -0.37 [-1.35, 0.46] no
NCEP GFS 17 -0.05 [-0.56, 0.54] no
GraphCast (IFS init) 17 -2.31 [-3.05, -1.40] yes
Persistence (baseline) 17 -0.13 [-0.93, 0.26] no

Cite this page

ShortCastCheck, ALL ifs_hres lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/ALL/model/ifs_hres/lead/8/

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 8. 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/8/

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

JSON CSV all scores methodology v0.2 licence