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

Trenton Mercer · ECMWF IFS HRES · lead day 6

KTTN · ifs_hres · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d19 1 QC4.18 [2.63, 5.95]4.18+1.89 [-1.45, 4.25]5.60 [3.17, 7.55]16% [0%, 26%]21%53%-0.12-0.222026-08-07 → 2026-08-30
tmax00Zbilinear90d19 1 QC4.18 [2.52, 6.47]4.18+1.89 [-2.97, 4.32]5.60 [3.02, 7.70]16% [0%, 27%]21%53%-0.12-0.222026-08-07 → 2026-08-30
tmax00Zbilinear365d19 1 QC4.18 [2.52, 6.43]4.18+1.89 [-2.30, 4.49]5.60 [2.97, 7.82]16% [0%, 28%]21%53%-0.12-0.222026-08-07 → 2026-08-30
tmax00Zbilinearall19 1 QC4.18 [2.49, 6.37]4.18+1.89 [-2.21, 4.44]5.60 [2.95, 7.76]16% [0%, 29%]21%53%-0.12-0.222026-08-07 → 2026-08-30
tmax00Znearest30d19 1 QC4.27 [2.58, 6.27]4.32+2.04 [-1.42, 4.62]5.86 [3.20, 8.09]16% [0%, 26%]26%53%-0.14-0.262026-08-07 → 2026-08-30
tmax00Znearest90d19 1 QC4.27 [2.47, 6.66]4.32+2.04 [-2.62, 4.77]5.86 [3.07, 8.13]16% [0%, 27%]26%53%-0.14-0.262026-08-07 → 2026-08-30
tmax00Znearest365d19 1 QC4.27 [2.49, 6.65]4.32+2.04 [-2.03, 4.88]5.86 [3.03, 8.27]16% [0%, 28%]26%53%-0.14-0.262026-08-07 → 2026-08-30
tmax00Znearestall19 1 QC4.27 [2.44, 6.65]4.32+2.04 [-2.12, 4.87]5.86 [2.98, 8.27]16% [0%, 29%]26%53%-0.14-0.262026-08-07 → 2026-08-30
tmax12Zbilinear30d19 1 QC3.42 [2.67, 4.91]3.31+0.95 [-1.51, 2.47]4.31 [3.24, 5.79]21% [0%, 33%]42%47%+0.08+0.042026-08-07 → 2026-08-30
tmax12Zbilinear90d19 1 QC3.42 [2.67, 5.75]3.31+0.95 [-3.08, 2.54]4.31 [3.25, 6.49]21% [0%, 33%]42%47%+0.08+0.042026-08-07 → 2026-08-30
tmax12Zbilinear365d19 1 QC3.42 [2.60, 5.73]3.31+0.95 [-3.09, 2.63]4.31 [3.11, 6.31]21% [0%, 36%]42%47%+0.08+0.042026-08-07 → 2026-08-30
tmax12Zbilinearall19 1 QC3.42 [2.60, 5.69]3.31+0.95 [-2.53, 2.60]4.31 [3.00, 6.52]21% [0%, 33%]42%47%+0.08+0.042026-08-07 → 2026-08-30
tmax12Znearest30d19 1 QC3.45 [2.70, 4.91]3.28+1.00 [-1.51, 2.55]4.33 [3.25, 5.77]21% [9%, 29%]37%53%+0.08+0.052026-08-07 → 2026-08-30
tmax12Znearest90d19 1 QC3.45 [2.69, 5.67]3.28+1.00 [-2.85, 2.65]4.33 [3.25, 6.41]21% [0%, 29%]37%53%+0.08+0.052026-08-07 → 2026-08-30
tmax12Znearest365d19 1 QC3.45 [2.65, 5.68]3.28+1.00 [-3.05, 2.72]4.33 [3.16, 6.27]21% [0%, 29%]37%53%+0.08+0.052026-08-07 → 2026-08-30
tmax12Znearestall19 1 QC3.45 [2.60, 5.64]3.28+1.00 [-2.50, 2.67]4.33 [3.05, 6.49]21% [0%, 29%]37%53%+0.08+0.052026-08-07 → 2026-08-30
tmin00Zbilinear30d19 1 QC4.77 [3.40, 5.80]2.82+4.77 [3.40, 5.80]5.70 [4.27, 6.58]11% [0%, 21%]21%37%-0.28+0.132026-08-07 → 2026-08-30
tmin00Zbilinear90d19 1 QC4.77 [3.32, 6.00]2.82+4.77 [3.32, 6.00]5.70 [3.49, 6.72]11% [0%, 21%]21%37%-0.28+0.132026-08-07 → 2026-08-30
tmin00Zbilinear365d19 1 QC4.77 [3.31, 6.01]2.82+4.77 [3.31, 6.01]5.70 [3.49, 6.75]11% [0%, 21%]21%37%-0.28+0.132026-08-07 → 2026-08-30
tmin00Zbilinearall19 1 QC4.77 [3.34, 6.09]2.82+4.77 [3.34, 6.09]5.70 [3.49, 6.77]11% [0%, 21%]21%37%-0.28+0.132026-08-07 → 2026-08-30
tmin00Znearest30d19 1 QC5.04 [3.71, 6.06]2.77+5.04 [3.71, 6.06]5.91 [4.47, 6.80]11% [0%, 21%]16%21%-0.35+0.152026-08-07 → 2026-08-30
tmin00Znearest90d19 1 QC5.04 [3.59, 6.26]2.77+5.04 [3.59, 6.26]5.91 [3.59, 6.95]11% [0%, 21%]16%21%-0.35+0.152026-08-07 → 2026-08-30
tmin00Znearest365d19 1 QC5.04 [3.59, 6.31]2.77+5.04 [3.59, 6.31]5.91 [3.59, 7.03]11% [0%, 21%]16%21%-0.35+0.152026-08-07 → 2026-08-30
tmin00Znearestall19 1 QC5.04 [3.59, 6.33]2.77+5.04 [3.59, 6.33]5.91 [3.59, 7.04]11% [0%, 21%]16%21%-0.35+0.152026-08-07 → 2026-08-30
tmin12Zbilinear30d19 1 QC4.45 [2.72, 5.99]3.06+4.30 [2.36, 5.94]5.62 [3.25, 7.12]16% [0%, 25%]32%47%-0.19+0.062026-08-07 → 2026-08-30
tmin12Zbilinear90d19 1 QC4.45 [2.43, 6.31]3.06+4.30 [1.98, 6.31]5.62 [2.62, 7.61]16% [0%, 25%]32%47%-0.19+0.062026-08-07 → 2026-08-30
tmin12Zbilinear365d19 1 QC4.45 [2.50, 6.38]3.06+4.30 [2.03, 6.36]5.62 [2.62, 7.58]16% [0%, 27%]32%47%-0.19+0.062026-08-07 → 2026-08-30
tmin12Zbilinearall19 1 QC4.45 [2.44, 6.65]3.06+4.30 [2.03, 6.59]5.62 [2.62, 7.71]16% [0%, 26%]32%47%-0.19+0.062026-08-07 → 2026-08-30
tmin12Znearest30d19 1 QC4.67 [2.93, 6.23]3.02+4.56 [2.63, 6.19]5.81 [3.43, 7.32]16% [0%, 25%]26%42%-0.25+0.072026-08-07 → 2026-08-30
tmin12Znearest90d19 1 QC4.67 [2.65, 6.62]3.02+4.56 [2.30, 6.62]5.81 [2.70, 7.87]16% [0%, 25%]26%42%-0.25+0.072026-08-07 → 2026-08-30
tmin12Znearest365d19 1 QC4.67 [2.70, 6.64]3.02+4.56 [2.37, 6.64]5.81 [2.70, 7.76]16% [0%, 27%]26%42%-0.25+0.072026-08-07 → 2026-08-30
tmin12Znearestall19 1 QC4.67 [2.68, 6.89]3.02+4.56 [2.35, 6.85]5.81 [2.70, 7.97]16% [0%, 26%]26%42%-0.25+0.072026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: -6.79 °F2026-08-13: +4.53 °F2026-08-14: +0.38 °F2026-08-15: -2.64 °F2026-08-16: +15.14 °F2026-08-17: +7.96 °F2026-08-18: +3.77 °F2026-08-19: -2.13 °F2026-08-20: +11.23 °F2026-08-21: +3.96 °F2026-08-22: +0.42 °F2026-08-23: -2.68 °F2026-08-24: +2.19 °F2026-08-25: +0.08 °F2026-08-26: -2.59 °F2026-08-27: +2.55 °F2026-08-28: -3.48 °F2026-08-29: +5.44 °F2026-08-30: -1.37 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.37
2026-08-29+5.44
2026-08-28-3.48
2026-08-27+2.55
2026-08-26-2.59
2026-08-25+0.08
2026-08-24+2.19
2026-08-23-2.68
2026-08-22+0.42
2026-08-21+3.96
2026-08-20+11.23
2026-08-19-2.13
2026-08-18+3.77
2026-08-17+7.96
2026-08-16+15.14
2026-08-15-2.64
2026-08-14+0.38
2026-08-13+4.53
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07-6.79

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 6-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 1 day-6 to -4 °F: 0 days-4 to -2 °F: 5 days-2 to 0 °F: 1 day0 to 2 °F: 3 days2 to 4 °F: 4 days4 to 6 °F: 2 days6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 1 day16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 2.68 · P90 |e| 8.62 °F-200+20 °Fn = 19 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.000
-10.00-8.000
-8.00-6.001
-6.00-4.000
-4.00-2.005
-2.00+0.001
+0.00+2.003
+2.00+4.004
+4.00+6.002
+6.00+8.001
+8.00+10.000
+10.00+12.001
+12.00+14.000
+14.00+16.001
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08194.18 +1.89

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19

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 19 +2.22 [0.49, 4.35] yes
NCEP GFS 19 +0.71 [-1.59, 3.89] no
GraphCast (IFS init) 19 +1.99 [0.40, 3.96] yes
Persistence (baseline) 19 +0.44 [-1.56, 2.74] no

Cite this page

ShortCastCheck, KTTN ifs_hres lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, lead day 6. 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/6/

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