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

Atlanta Hartsfield · ECMWF IFS HRES · lead day 9

KATL · ifs_hres · lead 9

Target day = initialization date + 9 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
tmax00Zbilinear30d16 1 QC3.54 [2.71, 4.43]3.78-1.11 [-4.00, 1.29]4.74 [3.68, 5.67]38% [21%, 50%]38%50%+0.10+0.022026-08-10 → 2026-08-30
tmax00Zbilinear90d16 1 QC3.54 [2.62, 4.47]3.78-1.11 [-4.23, 1.40]4.74 [3.29, 5.72]38% [0%, 50%]38%50%+0.10+0.022026-08-10 → 2026-08-30
tmax00Zbilinear365d16 1 QC3.54 [2.70, 4.49]3.78-1.11 [-4.23, 1.65]4.74 [3.43, 5.73]38% [0%, 50%]38%50%+0.10+0.022026-08-10 → 2026-08-30
tmax00Zbilinearall16 1 QC3.54 [2.55, 4.46]3.78-1.11 [-4.22, 1.45]4.74 [3.26, 5.70]38% [0%, 52%]38%50%+0.10+0.022026-08-10 → 2026-08-30
tmax00Znearest30d16 1 QC3.82 [3.03, 4.51]3.99-0.71 [-3.96, 1.86]4.94 [3.88, 5.72]31% [17%, 46%]38%38%+0.03-0.042026-08-10 → 2026-08-30
tmax00Znearest90d16 1 QC3.82 [2.90, 4.49]3.99-0.71 [-4.23, 2.04]4.94 [3.50, 5.72]31% [0%, 50%]38%38%+0.03-0.042026-08-10 → 2026-08-30
tmax00Znearest365d16 1 QC3.82 [2.98, 4.53]3.99-0.71 [-4.23, 2.20]4.94 [3.64, 5.79]31% [0%, 50%]38%38%+0.03-0.042026-08-10 → 2026-08-30
tmax00Znearestall16 1 QC3.82 [2.91, 4.54]3.99-0.71 [-4.22, 1.89]4.94 [3.49, 5.77]31% [0%, 50%]38%38%+0.03-0.042026-08-10 → 2026-08-30
tmax12Zbilinear30d15 1 QC4.06 [3.12, 5.23]3.80-1.51 [-4.46, 1.43]4.97 [3.94, 5.95]20% [0%, 31%]33%40%+0.02+0.052026-08-10 → 2026-08-30
tmax12Zbilinear90d15 1 QC4.06 [3.18, 5.87]3.80-1.51 [-5.56, 1.52]4.97 [3.96, 5.98]20% [0%, 31%]33%40%+0.02+0.052026-08-10 → 2026-08-30
tmax12Zbilinear365d15 1 QC4.06 [3.11, 5.79]3.80-1.51 [-5.24, 1.96]4.97 [3.76, 5.98]20% [0%, 33%]33%40%+0.02+0.052026-08-10 → 2026-08-30
tmax12Zbilinearall15 1 QC4.06 [3.05, 5.74]3.80-1.51 [-5.15, 1.67]4.97 [3.75, 5.98]20% [0%, 33%]33%40%+0.02+0.052026-08-10 → 2026-08-30
tmax12Znearest30d15 1 QC4.12 [3.01, 5.39]3.89-1.16 [-4.12, 1.71]5.01 [3.70, 6.09]13% [0%, 25%]40%40%+0.00+0.032026-08-10 → 2026-08-30
tmax12Znearest90d15 1 QC4.12 [3.04, 5.82]3.89-1.16 [-5.35, 1.85]5.01 [3.64, 6.10]13% [0%, 25%]40%40%+0.00+0.032026-08-10 → 2026-08-30
tmax12Znearest365d15 1 QC4.12 [3.00, 5.82]3.89-1.16 [-4.87, 2.28]5.01 [3.54, 6.14]13% [0%, 25%]40%40%+0.00+0.032026-08-10 → 2026-08-30
tmax12Znearestall15 1 QC4.12 [2.89, 5.82]3.89-1.16 [-4.91, 1.98]5.01 [3.52, 6.05]13% [0%, 28%]40%40%+0.00+0.032026-08-10 → 2026-08-30
tmin00Zbilinear30d16 1 QC2.66 [1.41, 3.91]2.25+1.72 [-0.13, 3.31]3.22 [1.73, 4.21]25% [0%, 55%]50%56%-0.01+0.092026-08-10 → 2026-08-30
tmin00Zbilinear90d16 1 QC2.66 [1.39, 3.98]2.25+1.72 [-0.31, 3.44]3.22 [1.71, 4.24]25% [0%, 57%]50%56%-0.01+0.092026-08-10 → 2026-08-30
tmin00Zbilinear365d16 1 QC2.66 [1.36, 4.08]2.25+1.72 [-0.32, 3.52]3.22 [1.72, 4.36]25% [0%, 58%]50%56%-0.01+0.092026-08-10 → 2026-08-30
tmin00Zbilinearall16 1 QC2.66 [1.36, 3.99]2.25+1.72 [-0.31, 3.40]3.22 [1.70, 4.26]25% [0%, 62%]50%56%-0.01+0.092026-08-10 → 2026-08-30
tmin00Znearest30d16 1 QC2.77 [1.43, 4.02]2.39+1.83 [-0.13, 3.44]3.36 [1.77, 4.35]25% [0%, 50%]31%56%-0.06+0.032026-08-10 → 2026-08-30
tmin00Znearest90d16 1 QC2.77 [1.37, 4.10]2.39+1.83 [-0.29, 3.62]3.36 [1.76, 4.42]25% [0%, 50%]31%56%-0.06+0.032026-08-10 → 2026-08-30
tmin00Znearest365d16 1 QC2.77 [1.35, 4.16]2.39+1.83 [-0.32, 3.69]3.36 [1.73, 4.46]25% [0%, 50%]31%56%-0.06+0.032026-08-10 → 2026-08-30
tmin00Znearestall16 1 QC2.77 [1.30, 4.09]2.39+1.83 [-0.29, 3.59]3.36 [1.71, 4.39]25% [0%, 55%]31%56%-0.06+0.032026-08-10 → 2026-08-30
tmin12Zbilinear30d15 1 QC3.48 [1.54, 5.10]3.51+0.17 [-1.99, 2.84]4.30 [1.64, 5.61]13% [0%, 29%]47%60%-0.34-0.522026-08-10 → 2026-08-30
tmin12Zbilinear90d15 1 QC3.48 [1.47, 5.13]3.51+0.17 [-2.07, 3.15]4.30 [1.57, 5.64]13% [0%, 30%]47%60%-0.34-0.522026-08-10 → 2026-08-30
tmin12Zbilinear365d15 1 QC3.48 [1.46, 5.25]3.51+0.17 [-2.07, 3.43]4.30 [1.55, 5.71]13% [0%, 30%]47%60%-0.34-0.522026-08-10 → 2026-08-30
tmin12Zbilinearall15 1 QC3.48 [1.45, 5.21]3.51+0.17 [-2.07, 3.15]4.30 [1.55, 5.70]13% [0%, 30%]47%60%-0.34-0.522026-08-10 → 2026-08-30
tmin12Znearest30d15 1 QC3.64 [1.47, 5.46]3.70+0.26 [-1.92, 2.99]4.53 [1.56, 5.95]7% [0%, 16%]47%53%-0.40-0.602026-08-10 → 2026-08-30
tmin12Znearest90d15 1 QC3.64 [1.43, 5.47]3.70+0.26 [-1.93, 3.36]4.53 [1.51, 5.97]7% [0%, 15%]47%53%-0.40-0.602026-08-10 → 2026-08-30
tmin12Znearest365d15 1 QC3.64 [1.40, 5.56]3.70+0.26 [-1.92, 3.46]4.53 [1.48, 6.04]7% [0%, 15%]47%53%-0.40-0.602026-08-10 → 2026-08-30
tmin12Znearestall15 1 QC3.64 [1.39, 5.56]3.70+0.26 [-1.99, 3.32]4.53 [1.48, 5.97]7% [0%, 16%]47%53%-0.40-0.602026-08-10 → 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 KATL, lead day 9, 00Z bilinear tmax+10+50-5-102026-08-10: -3.87 °F2026-08-16: -4.18 °F2026-08-17: +0.35 °F2026-08-18: +8.59 °F2026-08-19: -0.29 °F2026-08-20: +2.51 °F2026-08-21: +4.41 °F2026-08-22: +2.01 °F2026-08-23: -5.85 °F2026-08-24: -0.02 °F2026-08-25: +0.28 °F2026-08-26: -9.02 °F2026-08-27: +0.96 °F2026-08-28: -4.88 °F2026-08-29: -9.11 °F2026-08-30: +0.28 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.28
2026-08-29-9.11
2026-08-28-4.88
2026-08-27+0.96
2026-08-26-9.02
2026-08-25+0.28
2026-08-24-0.02
2026-08-23-5.85
2026-08-22+2.01
2026-08-21+4.41
2026-08-20+2.51
2026-08-19-0.29
2026-08-18+8.59
2026-08-17+0.35
2026-08-16-4.18
2026-08-15—
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10-3.87

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KATL, lead day 9-10 to -9 °F: 2 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 2 days-4 to -3 °F: 1 day-3 to -2 °F: 0 days-2 to -1 °F: 0 days-1 to 0 °F: 2 days0 to 1 °F: 4 days1 to 2 °F: 0 days2 to 3 °F: 2 days3 to 4 °F: 0 days4 to 5 °F: 1 day5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 1 day9 to 10 °F: 0 daysdashed: P50 |e| 3.19 · P90 |e| 8.81 °F-100+10 °Fn = 16 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
-10.00-9.002
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.002
-4.00-3.001
-3.00-2.000
-2.00-1.000
-1.00+0.002
+0.00+1.004
+1.00+2.000
+2.00+3.002
+3.00+4.000
+4.00+5.001
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.001
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08163.54 -1.11

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-10 → 2026-08-30 16
ECMWF IFS HRES2026-08-10 → 2026-08-30 16
ECMWF IFS HRES2026-08-10 → 2026-08-30 15
ECMWF IFS HRES2026-08-10 → 2026-08-30 15

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 16 -1.56 [-3.11, -0.41] yes
NCEP GFS 16 -1.04 [-2.83, 1.86] no
GraphCast (IFS init) 16 -1.92 [-4.81, -0.70] yes
Persistence (baseline) 16 -0.40 [-4.13, 0.55] no

Cite this page

ShortCastCheck, KATL ifs_hres lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KATL/model/ifs_hres/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KATL (Atlanta Hartsfield), model ifs_hres, lead day 9. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KATL/model/ifs_hres/lead/9/

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