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

Atlanta Hartsfield · ECMWF IFS HRES · lead day 3

KATL · ifs_hres · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d22 1 QC3.29 [2.71, 3.97]3.14-1.14 [-3.01, 0.69]4.09 [3.10, 5.04]14% [0%, 32%]32%45%-0.72-0.642026-08-04 → 2026-08-30
tmax00Zbilinear90d22 1 QC3.29 [2.68, 3.99]3.14-1.14 [-3.43, 0.72]4.09 [3.09, 5.07]14% [0%, 33%]32%45%-0.72-0.642026-08-04 → 2026-08-30
tmax00Zbilinear365d22 1 QC3.29 [2.66, 4.02]3.14-1.14 [-3.43, 0.87]4.09 [3.01, 5.15]14% [0%, 38%]32%45%-0.72-0.642026-08-04 → 2026-08-30
tmax00Zbilinearall22 1 QC3.29 [2.62, 4.02]3.14-1.14 [-3.43, 0.68]4.09 [2.96, 5.12]14% [0%, 33%]32%45%-0.72-0.642026-08-04 → 2026-08-30
tmax00Znearest30d22 1 QC3.42 [2.61, 4.18]3.38-0.78 [-2.84, 1.25]4.29 [3.14, 5.32]23% [9%, 38%]32%45%-0.79-0.772026-08-04 → 2026-08-30
tmax00Znearest90d22 1 QC3.42 [2.53, 4.20]3.38-0.78 [-3.18, 1.25]4.29 [3.08, 5.32]23% [0%, 43%]32%45%-0.79-0.772026-08-04 → 2026-08-30
tmax00Znearest365d22 1 QC3.42 [2.45, 4.23]3.38-0.78 [-3.20, 1.39]4.29 [2.97, 5.41]23% [0%, 44%]32%45%-0.79-0.772026-08-04 → 2026-08-30
tmax00Znearestall22 1 QC3.42 [2.46, 4.31]3.38-0.78 [-3.01, 1.26]4.29 [2.89, 5.44]23% [0%, 45%]32%45%-0.79-0.772026-08-04 → 2026-08-30
tmax12Zbilinear30d22 1 QC3.33 [2.25, 5.01]3.22-2.71 [-4.85, -1.37]4.49 [3.49, 5.75]36% [13%, 56%]50%55%-0.75-0.692026-08-04 → 2026-08-30
tmax12Zbilinear90d22 1 QC3.33 [2.21, 5.82]3.22-2.71 [-5.82, -1.34]4.49 [3.43, 6.19]36% [0%, 56%]50%55%-0.75-0.692026-08-04 → 2026-08-30
tmax12Zbilinear365d22 1 QC3.33 [2.23, 5.87]3.22-2.71 [-5.87, -1.31]4.49 [3.40, 6.23]36% [0%, 57%]50%55%-0.75-0.692026-08-04 → 2026-08-30
tmax12Zbilinearall22 1 QC3.33 [2.20, 5.89]3.22-2.71 [-5.89, -1.44]4.49 [3.48, 6.19]36% [0%, 57%]50%55%-0.75-0.692026-08-04 → 2026-08-30
tmax12Znearest30d22 1 QC3.30 [2.22, 5.19]3.28-2.45 [-4.84, -0.98]4.39 [3.27, 5.81]36% [11%, 50%]45%55%-0.73-0.722026-08-04 → 2026-08-30
tmax12Znearest90d22 1 QC3.30 [2.17, 6.17]3.28-2.45 [-6.14, -0.93]4.39 [3.22, 6.52]36% [0%, 52%]45%55%-0.73-0.722026-08-04 → 2026-08-30
tmax12Znearest365d22 1 QC3.30 [2.18, 6.05]3.28-2.45 [-6.05, -0.90]4.39 [3.17, 6.62]36% [0%, 52%]45%55%-0.73-0.722026-08-04 → 2026-08-30
tmax12Znearestall22 1 QC3.30 [2.18, 6.15]3.28-2.45 [-6.15, -1.04]4.39 [3.23, 6.43]36% [0%, 52%]45%55%-0.73-0.722026-08-04 → 2026-08-30
tmin00Zbilinear30d22 1 QC2.55 [1.48, 3.34]2.59+0.62 [-0.80, 1.98]3.17 [1.92, 3.92]27% [14%, 50%]45%64%-0.25-0.272026-08-04 → 2026-08-30
tmin00Zbilinear90d22 1 QC2.55 [1.19, 3.36]2.59+0.62 [-0.90, 2.11]3.17 [1.68, 3.93]27% [12%, 60%]45%64%-0.25-0.272026-08-04 → 2026-08-30
tmin00Zbilinear365d22 1 QC2.55 [1.19, 3.45]2.59+0.62 [-1.00, 2.20]3.17 [1.56, 3.96]27% [12%, 56%]45%64%-0.25-0.272026-08-04 → 2026-08-30
tmin00Zbilinearall22 1 QC2.55 [1.19, 3.37]2.59+0.62 [-1.14, 2.00]3.17 [1.46, 3.94]27% [14%, 60%]45%64%-0.25-0.272026-08-04 → 2026-08-30
tmin00Znearest30d22 1 QC2.65 [1.58, 3.50]2.60+0.71 [-0.64, 2.13]3.25 [1.93, 4.07]23% [12%, 45%]45%59%-0.30-0.272026-08-04 → 2026-08-30
tmin00Znearest90d22 1 QC2.65 [1.35, 3.55]2.60+0.71 [-0.84, 2.28]3.25 [1.66, 4.10]23% [11%, 57%]45%59%-0.30-0.272026-08-04 → 2026-08-30
tmin00Znearest365d22 1 QC2.65 [1.42, 3.62]2.60+0.71 [-0.91, 2.39]3.25 [1.73, 4.17]23% [11%, 50%]45%59%-0.30-0.272026-08-04 → 2026-08-30
tmin00Znearestall22 1 QC2.65 [1.29, 3.55]2.60+0.71 [-0.91, 2.17]3.25 [1.54, 4.11]23% [9%, 55%]45%59%-0.30-0.272026-08-04 → 2026-08-30
tmin12Zbilinear30d22 1 QC1.95 [1.43, 2.40]1.95+0.24 [-1.04, 1.30]2.36 [1.85, 2.71]32% [17%, 50%]59%73%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinear90d22 1 QC1.95 [1.24, 2.40]1.95+0.24 [-1.23, 1.28]2.36 [1.68, 2.73]32% [14%, 56%]59%73%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinear365d22 1 QC1.95 [1.20, 2.48]1.95+0.24 [-1.27, 1.44]2.36 [1.65, 2.78]32% [13%, 58%]59%73%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinearall22 1 QC1.95 [1.24, 2.44]1.95+0.24 [-1.31, 1.31]2.36 [1.67, 2.77]32% [13%, 60%]59%73%+0.05+0.052026-08-04 → 2026-08-30
tmin12Znearest30d22 1 QC1.89 [1.39, 2.32]1.88+0.20 [-0.99, 1.14]2.34 [1.87, 2.68]32% [17%, 50%]64%73%+0.08+0.082026-08-04 → 2026-08-30
tmin12Znearest90d22 1 QC1.89 [1.26, 2.38]1.88+0.20 [-1.23, 1.13]2.34 [1.67, 2.72]32% [14%, 56%]64%73%+0.08+0.082026-08-04 → 2026-08-30
tmin12Znearest365d22 1 QC1.89 [1.15, 2.42]1.88+0.20 [-1.28, 1.28]2.34 [1.66, 2.76]32% [13%, 58%]64%73%+0.08+0.082026-08-04 → 2026-08-30
tmin12Znearestall22 1 QC1.89 [1.22, 2.43]1.88+0.20 [-1.21, 1.14]2.34 [1.69, 2.79]32% [13%, 60%]64%73%+0.08+0.082026-08-04 → 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 3, 00Z bilinear tmax+20+100-10-202026-08-04: -3.43 °F2026-08-10: -5.2 °F2026-08-11: -4.09 °F2026-08-12: -3.16 °F2026-08-13: -4.2 °F2026-08-14: +2.07 °F2026-08-15: +1.95 °F2026-08-16: -1.32 °F2026-08-17: -1.35 °F2026-08-18: +5.17 °F2026-08-19: +2.33 °F2026-08-20: +4.11 °F2026-08-21: +3.74 °F2026-08-22: -3.83 °F2026-08-23: -1.32 °F2026-08-24: -0.23 °F2026-08-25: -11.36 °F2026-08-26: +3.55 °F2026-08-27: +0.78 °F2026-08-28: -6.87 °F2026-08-29: -0.35 °F2026-08-30: -2.03 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.03
2026-08-29-0.35
2026-08-28-6.87
2026-08-27+0.78
2026-08-26+3.55
2026-08-25-11.36
2026-08-24-0.23
2026-08-23-1.32
2026-08-22-3.83
2026-08-21+3.74
2026-08-20+4.11
2026-08-19+2.33
2026-08-18+5.17
2026-08-17-1.35
2026-08-16-1.32
2026-08-15+1.95
2026-08-14+2.07
2026-08-13-4.20
2026-08-12-3.16
2026-08-11-4.09
2026-08-10-5.20
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04-3.43

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KATL, lead day 3-20 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: 1 day-10 to -8 °F: 0 days-8 to -6 °F: 1 day-6 to -4 °F: 3 days-4 to -2 °F: 4 days-2 to 0 °F: 5 days0 to 2 °F: 2 days2 to 4 °F: 4 days4 to 6 °F: 2 days6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.29 · P90 |e| 5.2 °F-200+20 °Fn = 22 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
-12.00-10.001
-10.00-8.000
-8.00-6.001
-6.00-4.003
-4.00-2.004
-2.00+0.005
+0.00+2.002
+2.00+4.004
+4.00+6.002
+6.00+8.000
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08223.29 -1.14

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22

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 22 -0.93 [-1.75, -0.27] yes
NCEP GFS 22 +0.18 [-0.71, 1.37] no
GraphCast (IFS init) 20 -1.89 [-3.28, -0.57] yes
Persistence (baseline) 22 +1.38 [0.75, 2.31] yes

Cite this page

ShortCastCheck, KATL ifs_hres lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KATL/model/ifs_hres/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KATL (Atlanta Hartsfield), model ifs_hres, lead day 3. 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/3/

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