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

Trenton Mercer · ECMWF IFS HRES · lead day 5

KTTN · ifs_hres · lead 5

Target day = initialization date + 5 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, 1 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
tmax00Zbilinear30d18 1 QC3.04 [2.12, 4.42]2.97+0.87 [-1.25, 2.79]3.98 [2.66, 5.36]28% [9%, 40%]44%67%+0.14+0.142026-08-06 → 2026-08-30
tmax00Zbilinear90d18 1 QC3.04 [2.05, 4.80]2.97+0.87 [-2.35, 2.81]3.98 [2.48, 5.77]28% [0%, 41%]44%67%+0.14+0.142026-08-06 → 2026-08-30
tmax00Zbilinear365d18 1 QC3.04 [1.99, 4.91]2.97+0.87 [-1.94, 2.89]3.98 [2.31, 5.78]28% [0%, 40%]44%67%+0.14+0.142026-08-06 → 2026-08-30
tmax00Zbilinearall18 1 QC3.04 [2.02, 4.74]2.97+0.87 [-1.79, 2.82]3.98 [2.44, 5.62]28% [0%, 41%]44%67%+0.14+0.142026-08-06 → 2026-08-30
tmax00Znearest30d18 1 QC2.92 [1.93, 4.41]3.00+0.94 [-1.11, 2.91]3.96 [2.60, 5.40]33% [10%, 50%]44%61%+0.18+0.132026-08-06 → 2026-08-30
tmax00Znearest90d18 1 QC2.92 [1.89, 4.79]3.00+0.94 [-2.10, 2.93]3.96 [2.40, 5.58]33% [0%, 52%]44%61%+0.18+0.132026-08-06 → 2026-08-30
tmax00Znearest365d18 1 QC2.92 [1.82, 4.85]3.00+0.94 [-1.78, 3.07]3.96 [2.26, 5.59]33% [0%, 50%]44%61%+0.18+0.132026-08-06 → 2026-08-30
tmax00Znearestall18 1 QC2.92 [1.85, 4.72]3.00+0.94 [-1.66, 2.92]3.96 [2.36, 5.58]33% [0%, 53%]44%61%+0.18+0.132026-08-06 → 2026-08-30
tmax12Zbilinear30d20 1 QC2.91 [2.41, 3.56]2.91+0.33 [-0.90, 1.49]3.48 [2.86, 4.07]15% [0%, 32%]40%60%+0.16+0.112026-08-06 → 2026-08-30
tmax12Zbilinear90d20 1 QC2.91 [2.42, 3.58]2.91+0.33 [-1.25, 1.61]3.48 [2.82, 4.07]15% [0%, 33%]40%60%+0.16+0.112026-08-06 → 2026-08-30
tmax12Zbilinear365d20 1 QC2.91 [2.36, 3.62]2.91+0.33 [-1.31, 1.70]3.48 [2.83, 4.10]15% [0%, 33%]40%60%+0.16+0.112026-08-06 → 2026-08-30
tmax12Zbilinearall20 1 QC2.91 [2.36, 3.55]2.91+0.33 [-1.33, 1.72]3.48 [2.83, 4.03]15% [0%, 33%]40%60%+0.16+0.112026-08-06 → 2026-08-30
tmax12Znearest30d20 1 QC2.93 [2.38, 3.60]2.93+0.45 [-0.82, 1.67]3.51 [2.88, 4.15]10% [0%, 21%]45%55%+0.15+0.102026-08-06 → 2026-08-30
tmax12Znearest90d20 1 QC2.93 [2.38, 3.67]2.93+0.45 [-1.17, 1.75]3.51 [2.85, 4.14]10% [0%, 22%]45%55%+0.15+0.102026-08-06 → 2026-08-30
tmax12Znearest365d20 1 QC2.93 [2.31, 3.71]2.93+0.45 [-1.23, 1.88]3.51 [2.81, 4.20]10% [0%, 22%]45%55%+0.15+0.102026-08-06 → 2026-08-30
tmax12Znearestall20 1 QC2.93 [2.33, 3.64]2.93+0.45 [-1.25, 1.87]3.51 [2.84, 4.10]10% [0%, 22%]45%55%+0.15+0.102026-08-06 → 2026-08-30
tmin00Zbilinear30d18 1 QC4.57 [2.25, 6.26]3.37+4.32 [2.02, 6.05]5.87 [3.58, 7.43]17% [0%, 38%]39%39%-0.44-0.162026-08-06 → 2026-08-30
tmin00Zbilinear90d18 1 QC4.57 [1.02, 6.64]3.37+4.32 [1.02, 6.43]5.87 [1.14, 7.78]17% [0%, 40%]39%39%-0.44-0.162026-08-06 → 2026-08-30
tmin00Zbilinear365d18 1 QC4.57 [1.02, 6.72]3.37+4.32 [1.02, 6.59]5.87 [1.10, 7.91]17% [0%, 42%]39%39%-0.44-0.162026-08-06 → 2026-08-30
tmin00Zbilinearall18 1 QC4.57 [1.02, 6.58]3.37+4.32 [1.02, 6.57]5.87 [1.12, 7.91]17% [0%, 40%]39%39%-0.44-0.162026-08-06 → 2026-08-30
tmin00Znearest30d18 1 QC4.74 [2.40, 6.48]3.29+4.64 [2.38, 6.35]6.07 [3.74, 7.71]22% [7%, 40%]33%39%-0.50-0.132026-08-06 → 2026-08-30
tmin00Znearest90d18 1 QC4.74 [1.09, 6.90]3.29+4.64 [1.06, 6.78]6.07 [1.41, 8.09]22% [0%, 40%]33%39%-0.50-0.132026-08-06 → 2026-08-30
tmin00Znearest365d18 1 QC4.74 [1.04, 6.97]3.29+4.64 [1.04, 6.89]6.07 [1.34, 8.24]22% [0%, 43%]33%39%-0.50-0.132026-08-06 → 2026-08-30
tmin00Znearestall18 1 QC4.74 [1.09, 6.88]3.29+4.64 [1.07, 6.88]6.07 [1.38, 8.24]22% [0%, 41%]33%39%-0.50-0.132026-08-06 → 2026-08-30
tmin12Zbilinear30d20 1 QC3.98 [2.56, 5.17]2.45+3.91 [2.37, 5.12]4.86 [3.34, 6.01]20% [0%, 41%]30%45%-0.33+0.082026-08-06 → 2026-08-30
tmin12Zbilinear90d20 1 QC3.98 [1.90, 5.46]2.45+3.91 [1.63, 5.46]4.86 [2.23, 6.33]20% [0%, 42%]30%45%-0.33+0.082026-08-06 → 2026-08-30
tmin12Zbilinear365d20 1 QC3.98 [1.88, 5.57]2.45+3.91 [1.63, 5.57]4.86 [2.24, 6.41]20% [0%, 43%]30%45%-0.33+0.082026-08-06 → 2026-08-30
tmin12Zbilinearall20 1 QC3.98 [1.88, 5.66]2.45+3.91 [1.67, 5.63]4.86 [2.21, 6.52]20% [0%, 43%]30%45%-0.33+0.082026-08-06 → 2026-08-30
tmin12Znearest30d20 1 QC4.23 [2.74, 5.47]2.44+4.18 [2.59, 5.44]5.09 [3.57, 6.33]10% [0%, 21%]30%40%-0.41+0.092026-08-06 → 2026-08-30
tmin12Znearest90d20 1 QC4.23 [2.02, 5.78]2.44+4.18 [1.85, 5.78]5.09 [2.42, 6.62]10% [0%, 22%]30%40%-0.41+0.092026-08-06 → 2026-08-30
tmin12Znearest365d20 1 QC4.23 [1.97, 5.92]2.44+4.18 [1.85, 5.92]5.09 [2.45, 6.76]10% [0%, 22%]30%40%-0.41+0.092026-08-06 → 2026-08-30
tmin12Znearestall20 1 QC4.23 [2.03, 5.98]2.44+4.18 [1.89, 5.95]5.09 [2.40, 6.87]10% [0%, 22%]30%40%-0.41+0.092026-08-06 → 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 KTTN, lead day 5, 00Z bilinear tmax+10+50-5-102026-08-06: -5.81 °F2026-08-12: +2.73 °F2026-08-13: -2.39 °F2026-08-14: -0.86 °F2026-08-16: +8.99 °F2026-08-17: +7.12 °F2026-08-19: +0.84 °F2026-08-20: +5.86 °F2026-08-21: -0.19 °F2026-08-22: -5.69 °F2026-08-23: +1.03 °F2026-08-24: -0.43 °F2026-08-25: -1.5 °F2026-08-26: +0.64 °F2026-08-27: +4.55 °F2026-08-28: -2.71 °F2026-08-29: +2.06 °F2026-08-30: +1.36 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.36
2026-08-29+2.06
2026-08-28-2.71
2026-08-27+4.55
2026-08-26+0.64
2026-08-25-1.50
2026-08-24-0.43
2026-08-23+1.03
2026-08-22-5.69
2026-08-21-0.19
2026-08-20+5.86
2026-08-19+0.84
2026-08-18—
2026-08-17+7.12
2026-08-16+8.99
2026-08-15—
2026-08-14-0.86
2026-08-13-2.39
2026-08-12+2.73
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06-5.81

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 5-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 2 days-5 to -4 °F: 0 days-4 to -3 °F: 0 days-3 to -2 °F: 2 days-2 to -1 °F: 1 day-1 to 0 °F: 3 days0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 2 days3 to 4 °F: 0 days4 to 5 °F: 1 day5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 1 day8 to 9 °F: 1 day9 to 10 °F: 0 daysdashed: P50 |e| 2.23 · P90 |e| 6.24 °F-100+10 °Fn = 18 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
-10.00-9.000
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.000
-4.00-3.000
-3.00-2.002
-2.00-1.001
-1.00+0.003
+0.00+1.002
+1.00+2.002
+2.00+3.002
+3.00+4.000
+4.00+5.001
+5.00+6.001
+6.00+7.000
+7.00+8.001
+8.00+9.001
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08183.04 +0.87

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 20
ECMWF IFS HRES2026-08-06 → 2026-08-30 20

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 18 +1.45 [0.41, 3.23] yes
NCEP GFS 18 -1.67 [-3.67, 1.58] no
GraphCast (IFS init) 18 +1.15 [-0.20, 3.06] no
Persistence (baseline) 18 -0.51 [-2.00, 1.85] no

Cite this page

ShortCastCheck, KTTN ifs_hres lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, lead day 5. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/5/

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