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

Trenton Mercer · ECMWF IFS HRES · lead day 1

KTTN · ifs_hres · lead 1

Target day = initialization date + 1 day. 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
tmax00Zbilinear30d23 1 QC2.66 [1.99, 3.27]2.46-0.76 [-2.22, 1.11]3.58 [2.53, 4.43]35% [23%, 54%]52%65%-0.15-0.082026-08-02 → 2026-08-30
tmax00Zbilinear90d23 1 QC2.66 [1.84, 3.29]2.46-0.76 [-2.29, 1.05]3.58 [2.24, 4.44]35% [22%, 60%]52%65%-0.15-0.082026-08-02 → 2026-08-30
tmax00Zbilinear365d23 1 QC2.66 [1.82, 3.28]2.46-0.76 [-2.37, 1.18]3.58 [2.25, 4.45]35% [22%, 60%]52%65%-0.15-0.082026-08-02 → 2026-08-30
tmax00Zbilinearall23 1 QC2.66 [1.75, 3.19]2.46-0.76 [-2.36, 1.19]3.58 [2.23, 4.31]35% [22%, 75%]52%65%-0.15-0.082026-08-02 → 2026-08-30
tmax00Znearest30d23 1 QC2.58 [1.91, 3.22]2.43-0.78 [-2.27, 1.14]3.55 [2.53, 4.37]39% [25%, 59%]57%65%-0.12-0.062026-08-02 → 2026-08-30
tmax00Znearest90d23 1 QC2.58 [1.77, 3.27]2.43-0.78 [-2.33, 1.10]3.55 [2.19, 4.39]39% [25%, 62%]57%65%-0.12-0.062026-08-02 → 2026-08-30
tmax00Znearest365d23 1 QC2.58 [1.74, 3.27]2.43-0.78 [-2.40, 1.22]3.55 [2.19, 4.40]39% [25%, 62%]57%65%-0.12-0.062026-08-02 → 2026-08-30
tmax00Znearestall23 1 QC2.58 [1.67, 3.12]2.43-0.78 [-2.40, 1.24]3.55 [2.14, 4.27]39% [25%, 75%]57%65%-0.12-0.062026-08-02 → 2026-08-30
tmax12Zbilinear30d24 1 QC2.07 [1.46, 2.59]2.00-0.66 [-1.91, 0.60]2.73 [1.90, 3.51]33% [21%, 45%]46%75%+0.11+0.132026-08-02 → 2026-08-30
tmax12Zbilinear90d24 1 QC2.07 [1.35, 2.58]2.00-0.66 [-1.99, 0.76]2.73 [1.83, 3.51]33% [20%, 50%]46%75%+0.11+0.132026-08-02 → 2026-08-30
tmax12Zbilinear365d24 1 QC2.07 [1.41, 2.59]2.00-0.66 [-2.06, 0.76]2.73 [1.81, 3.55]33% [20%, 50%]46%75%+0.11+0.132026-08-02 → 2026-08-30
tmax12Zbilinearall24 1 QC2.07 [1.33, 2.60]2.00-0.66 [-2.05, 0.76]2.73 [1.69, 3.56]33% [20%, 53%]46%75%+0.11+0.132026-08-02 → 2026-08-30
tmax12Znearest30d24 1 QC2.04 [1.42, 2.54]1.98-0.66 [-1.97, 0.77]2.79 [1.90, 3.53]42% [32%, 55%]54%71%+0.12+0.142026-08-02 → 2026-08-30
tmax12Znearest90d24 1 QC2.04 [1.33, 2.52]1.98-0.66 [-2.05, 0.91]2.79 [1.81, 3.50]42% [31%, 60%]54%71%+0.12+0.142026-08-02 → 2026-08-30
tmax12Znearest365d24 1 QC2.04 [1.32, 2.53]1.98-0.66 [-2.07, 0.96]2.79 [1.75, 3.54]42% [31%, 57%]54%71%+0.12+0.142026-08-02 → 2026-08-30
tmax12Znearestall24 1 QC2.04 [1.17, 2.54]1.98-0.66 [-2.11, 0.94]2.79 [1.55, 3.50]42% [32%, 57%]54%71%+0.12+0.142026-08-02 → 2026-08-30
tmin00Zbilinear30d23 1 QC3.34 [2.57, 4.12]1.84+3.26 [2.46, 4.06]3.93 [3.24, 4.56]22% [10%, 37%]30%39%-0.18+0.342026-08-02 → 2026-08-30
tmin00Zbilinear90d23 1 QC3.34 [2.31, 4.29]1.84+3.26 [2.19, 4.24]3.93 [3.08, 4.60]22% [6%, 44%]30%39%-0.18+0.342026-08-02 → 2026-08-30
tmin00Zbilinear365d23 1 QC3.34 [2.28, 4.37]1.84+3.26 [2.19, 4.33]3.93 [3.01, 4.67]22% [0%, 44%]30%39%-0.18+0.342026-08-02 → 2026-08-30
tmin00Zbilinearall23 1 QC3.34 [2.30, 4.30]1.84+3.26 [2.18, 4.24]3.93 [3.08, 4.67]22% [5%, 47%]30%39%-0.18+0.342026-08-02 → 2026-08-30
tmin00Znearest30d23 1 QC3.51 [2.73, 4.31]1.89+3.47 [2.68, 4.27]4.12 [3.42, 4.75]22% [10%, 37%]30%39%-0.24+0.322026-08-02 → 2026-08-30
tmin00Znearest90d23 1 QC3.51 [2.44, 4.47]1.89+3.47 [2.41, 4.41]4.12 [3.22, 4.80]22% [6%, 44%]30%39%-0.24+0.322026-08-02 → 2026-08-30
tmin00Znearest365d23 1 QC3.51 [2.42, 4.56]1.89+3.47 [2.38, 4.52]4.12 [3.17, 4.91]22% [0%, 44%]30%39%-0.24+0.322026-08-02 → 2026-08-30
tmin00Znearestall23 1 QC3.51 [2.39, 4.51]1.89+3.47 [2.38, 4.48]4.12 [3.22, 4.90]22% [5%, 47%]30%39%-0.24+0.322026-08-02 → 2026-08-30
tmin12Zbilinear30d24 1 QC3.64 [2.95, 4.26]1.72+3.64 [2.95, 4.26]4.19 [3.57, 4.69]17% [7%, 30%]25%38%-0.34+0.362026-08-02 → 2026-08-30
tmin12Zbilinear90d24 1 QC3.64 [2.76, 4.28]1.72+3.64 [2.76, 4.28]4.19 [3.42, 4.69]17% [0%, 38%]25%38%-0.34+0.362026-08-02 → 2026-08-30
tmin12Zbilinear365d24 1 QC3.64 [2.71, 4.39]1.72+3.64 [2.71, 4.39]4.19 [3.31, 4.75]17% [0%, 35%]25%38%-0.34+0.362026-08-02 → 2026-08-30
tmin12Zbilinearall24 1 QC3.64 [2.63, 4.39]1.72+3.64 [2.63, 4.39]4.19 [3.26, 4.75]17% [0%, 40%]25%38%-0.34+0.362026-08-02 → 2026-08-30
tmin12Znearest30d24 1 QC3.89 [3.19, 4.51]1.74+3.88 [3.15, 4.50]4.40 [3.75, 4.91]12% [0%, 29%]17%38%-0.44+0.352026-08-02 → 2026-08-30
tmin12Znearest90d24 1 QC3.89 [2.98, 4.52]1.74+3.88 [2.96, 4.52]4.40 [3.63, 4.90]12% [0%, 36%]17%38%-0.44+0.352026-08-02 → 2026-08-30
tmin12Znearest365d24 1 QC3.89 [2.95, 4.64]1.74+3.88 [2.88, 4.63]4.40 [3.51, 4.98]12% [0%, 34%]17%38%-0.44+0.352026-08-02 → 2026-08-30
tmin12Znearestall24 1 QC3.89 [2.77, 4.63]1.74+3.88 [2.69, 4.63]4.40 [3.42, 4.99]12% [0%, 39%]17%38%-0.44+0.352026-08-02 → 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 1, 00Z bilinear tmax+10+50-5-102026-08-02: -0.88 °F2026-08-09: -2.33 °F2026-08-10: +4.12 °F2026-08-11: +1.29 °F2026-08-12: -0.7 °F2026-08-13: -0.55 °F2026-08-14: +3.56 °F2026-08-15: +2.83 °F2026-08-16: +7.43 °F2026-08-17: -2.91 °F2026-08-18: -0.63 °F2026-08-19: -1.26 °F2026-08-20: -9.84 °F2026-08-21: +0 °F2026-08-22: -3.24 °F2026-08-23: -0.77 °F2026-08-24: -3.25 °F2026-08-25: -1.18 °F2026-08-26: +1.73 °F2026-08-27: -5.6 °F2026-08-28: -5.18 °F2026-08-29: -0.98 °F2026-08-30: +0.87 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.87
2026-08-29-0.98
2026-08-28-5.18
2026-08-27-5.60
2026-08-26+1.73
2026-08-25-1.18
2026-08-24-3.25
2026-08-23-0.77
2026-08-22-3.24
2026-08-21+0.00
2026-08-20-9.84
2026-08-19-1.26
2026-08-18-0.63
2026-08-17-2.91
2026-08-16+7.43
2026-08-15+2.83
2026-08-14+3.56
2026-08-13-0.55
2026-08-12-0.70
2026-08-11+1.29
2026-08-10+4.12
2026-08-09-2.33
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02-0.88

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 1-10 to -9 °F: 1 day-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: 2 days-3 to -2 °F: 2 days-2 to -1 °F: 2 days-1 to 0 °F: 6 days0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 to 5 °F: 1 day5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 1.73 · P90 |e| 5.52 °F-100+10 °Fn = 23 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
-10.00-9.001
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.000
-4.00-3.002
-3.00-2.002
-2.00-1.002
-1.00+0.006
+0.00+1.002
+1.00+2.002
+2.00+3.001
+3.00+4.001
+4.00+5.001
+5.00+6.000
+6.00+7.000
+7.00+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08232.66 -0.76

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-02 → 2026-08-30 23
ECMWF IFS HRES2026-08-02 → 2026-08-30 23
ECMWF IFS HRES2026-08-02 → 2026-08-30 24
ECMWF IFS HRES2026-08-02 → 2026-08-30 24

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 23 +0.94 [-0.25, 1.72] no
Aurora (GFS init) 1 -1.56 [-1.56, -1.56] yes
Aurora (IFS init) 2 +0.38 [-0.12, 0.88] no
FourCastNet v2 (GFS init) 1 -0.33 [-0.33, -0.33] yes
FourCastNet v2 (IFS init) 2 -1.73 [-2.34, -1.13] yes
NCEP GFS 23 -0.22 [-1.06, 0.50] no
GraphCast (GFS init) 1 -2.58 [-2.58, -2.58] yes
GraphCast (IFS init) 21 +0.57 [-0.97, 1.39] no
Pangu-Weather (GFS init) 1 -1.59 [-1.59, -1.59] yes
Pangu-Weather (IFS init) 2 -1.88 [-3.09, -0.68] yes
Persistence (baseline) 23 +0.35 [-0.70, 1.09] no

Cite this page

ShortCastCheck, KTTN ifs_hres lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, lead day 1. 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/1/

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