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

Atlanta Hartsfield · ECMWF AIFS Single · lead day 1

KATL · aifs_single · 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, aifs-single-gpid5, 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
tmax00Zbilinear30d29 1 QC4.31 [3.79, 4.83]1.30-4.31 [-4.83, -3.79]4.58 [4.09, 5.07]3% [0%, 10%]3%24%-0.95+0.422026-08-02 → 2026-08-30
tmax00Zbilinear90d29 1 QC4.31 [3.79, 5.01]1.30-4.31 [-5.01, -3.79]4.58 [4.07, 5.23]3% [0%, 10%]3%24%-0.95+0.422026-08-02 → 2026-08-30
tmax00Zbilinear365d29 1 QC4.31 [3.75, 4.97]1.30-4.31 [-4.97, -3.75]4.58 [4.02, 5.20]3% [0%, 11%]3%24%-0.95+0.422026-08-02 → 2026-08-30
tmax00Zbilinearall29 1 QC4.31 [3.73, 4.99]1.30-4.31 [-4.99, -3.73]4.58 [3.99, 5.20]3% [0%, 11%]3%24%-0.95+0.422026-08-02 → 2026-08-30
tmax00Znearest30d29 1 QC4.41 [3.87, 4.95]1.33-4.41 [-4.95, -3.87]4.68 [4.17, 5.17]0% [0%, 0%]3%28%-1.00+0.402026-08-02 → 2026-08-30
tmax00Znearest90d29 1 QC4.41 [3.84, 5.11]1.33-4.41 [-5.11, -3.84]4.68 [4.13, 5.32]0% [0%, 0%]3%28%-1.00+0.402026-08-02 → 2026-08-30
tmax00Znearest365d29 1 QC4.41 [3.82, 5.07]1.33-4.41 [-5.07, -3.82]4.68 [4.08, 5.31]0% [0%, 0%]3%28%-1.00+0.402026-08-02 → 2026-08-30
tmax00Znearestall29 1 QC4.41 [3.77, 5.09]1.33-4.41 [-5.09, -3.77]4.68 [4.06, 5.30]0% [0%, 0%]3%28%-1.00+0.402026-08-02 → 2026-08-30
tmax12Zbilinear30d29 1 QC4.33 [4.01, 4.63]1.17-4.33 [-4.63, -4.01]4.57 [4.28, 4.84]0% [0%, 0%]7%17%-0.96+0.482026-08-02 → 2026-08-30
tmax12Zbilinear90d29 1 QC4.33 [4.00, 4.74]1.17-4.33 [-4.74, -4.00]4.57 [4.24, 4.95]0% [0%, 0%]7%17%-0.96+0.482026-08-02 → 2026-08-30
tmax12Zbilinear365d29 1 QC4.33 [3.96, 4.70]1.17-4.33 [-4.70, -3.96]4.57 [4.20, 4.92]0% [0%, 0%]7%17%-0.96+0.482026-08-02 → 2026-08-30
tmax12Zbilinearall29 1 QC4.33 [3.97, 4.70]1.17-4.33 [-4.70, -3.97]4.57 [4.22, 4.93]0% [0%, 0%]7%17%-0.96+0.482026-08-02 → 2026-08-30
tmax12Znearest30d29 1 QC4.44 [4.09, 4.79]1.17-4.44 [-4.79, -4.09]4.67 [4.32, 4.98]0% [0%, 0%]7%17%-1.01+0.472026-08-02 → 2026-08-30
tmax12Znearest90d29 1 QC4.44 [4.05, 4.90]1.17-4.44 [-4.90, -4.05]4.67 [4.25, 5.11]0% [0%, 0%]7%17%-1.01+0.472026-08-02 → 2026-08-30
tmax12Znearest365d29 1 QC4.44 [4.00, 4.87]1.17-4.44 [-4.87, -4.00]4.67 [4.20, 5.08]0% [0%, 0%]7%17%-1.01+0.472026-08-02 → 2026-08-30
tmax12Znearestall29 1 QC4.44 [4.02, 4.86]1.17-4.44 [-4.86, -4.02]4.67 [4.25, 5.07]0% [0%, 0%]7%17%-1.01+0.472026-08-02 → 2026-08-30
tmin00Zbilinear30d29 1 QC1.48 [0.90, 1.97]1.47-0.27 [-1.24, 0.38]1.91 [1.23, 2.37]41% [20%, 69%]69%90%+0.22+0.222026-08-02 → 2026-08-30
tmin00Zbilinear90d29 1 QC1.48 [0.81, 1.97]1.47-0.27 [-1.26, 0.46]1.91 [1.07, 2.33]41% [17%, 72%]69%90%+0.22+0.222026-08-02 → 2026-08-30
tmin00Zbilinear365d29 1 QC1.48 [0.79, 1.99]1.47-0.27 [-1.38, 0.48]1.91 [1.07, 2.38]41% [17%, 72%]69%90%+0.22+0.222026-08-02 → 2026-08-30
tmin00Zbilinearall29 1 QC1.48 [0.78, 1.99]1.47-0.27 [-1.48, 0.49]1.91 [1.02, 2.42]41% [17%, 73%]69%90%+0.22+0.222026-08-02 → 2026-08-30
tmin00Znearest30d29 1 QC1.51 [0.90, 2.02]1.47-0.36 [-1.36, 0.31]1.95 [1.23, 2.44]41% [20%, 69%]69%86%+0.21+0.222026-08-02 → 2026-08-30
tmin00Znearest90d29 1 QC1.51 [0.81, 2.01]1.47-0.36 [-1.37, 0.39]1.95 [1.08, 2.40]41% [17%, 72%]69%86%+0.21+0.222026-08-02 → 2026-08-30
tmin00Znearest365d29 1 QC1.51 [0.80, 2.03]1.47-0.36 [-1.49, 0.41]1.95 [1.07, 2.47]41% [17%, 72%]69%86%+0.21+0.222026-08-02 → 2026-08-30
tmin00Znearestall29 1 QC1.51 [0.79, 2.04]1.47-0.36 [-1.62, 0.42]1.95 [1.02, 2.51]41% [17%, 73%]69%86%+0.21+0.222026-08-02 → 2026-08-30
tmin12Zbilinear30d29 1 QC1.46 [1.02, 1.84]1.41-0.32 [-1.00, 0.24]1.77 [1.27, 2.15]45% [27%, 69%]76%86%+0.23+0.252026-08-02 → 2026-08-30
tmin12Zbilinear90d29 1 QC1.46 [0.97, 1.83]1.41-0.32 [-1.03, 0.35]1.77 [1.17, 2.13]45% [27%, 73%]76%86%+0.23+0.252026-08-02 → 2026-08-30
tmin12Zbilinear365d29 1 QC1.46 [0.97, 1.88]1.41-0.32 [-1.13, 0.35]1.77 [1.16, 2.17]45% [25%, 73%]76%86%+0.23+0.252026-08-02 → 2026-08-30
tmin12Zbilinearall29 1 QC1.46 [0.95, 1.83]1.41-0.32 [-1.19, 0.36]1.77 [1.13, 2.14]45% [26%, 75%]76%86%+0.23+0.252026-08-02 → 2026-08-30
tmin12Znearest30d29 1 QC1.49 [1.03, 1.87]1.42-0.41 [-1.13, 0.17]1.80 [1.29, 2.17]34% [17%, 59%]76%90%+0.21+0.252026-08-02 → 2026-08-30
tmin12Znearest90d29 1 QC1.49 [0.96, 1.85]1.42-0.41 [-1.16, 0.26]1.80 [1.17, 2.15]34% [17%, 62%]76%90%+0.21+0.252026-08-02 → 2026-08-30
tmin12Znearest365d29 1 QC1.49 [0.95, 1.90]1.42-0.41 [-1.27, 0.27]1.80 [1.17, 2.18]34% [14%, 64%]76%90%+0.21+0.252026-08-02 → 2026-08-30
tmin12Znearestall29 1 QC1.49 [0.92, 1.86]1.42-0.41 [-1.33, 0.29]1.80 [1.11, 2.16]34% [14%, 65%]76%90%+0.21+0.252026-08-02 → 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 AIFS Single at KATL, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -7.12 °F2026-08-03: -3.93 °F2026-08-04: -3.15 °F2026-08-05: -7.32 °F2026-08-06: -4.62 °F2026-08-07: -4.62 °F2026-08-08: -4.91 °F2026-08-09: -4.34 °F2026-08-10: -6.09 °F2026-08-11: -2.91 °F2026-08-12: -3.78 °F2026-08-13: -5.52 °F2026-08-14: -2.85 °F2026-08-15: -3.43 °F2026-08-16: -3.14 °F2026-08-17: -2.72 °F2026-08-18: -0.82 °F2026-08-19: -6.01 °F2026-08-20: -6.3 °F2026-08-21: -6.39 °F2026-08-22: -4.8 °F2026-08-23: -2.38 °F2026-08-24: -3.47 °F2026-08-25: -4.75 °F2026-08-26: -2.75 °F2026-08-27: -2.33 °F2026-08-28: -6.2 °F2026-08-29: -4.46 °F2026-08-30: -3.83 °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
2026-08-30-3.83
2026-08-29-4.46
2026-08-28-6.20
2026-08-27-2.33
2026-08-26-2.75
2026-08-25-4.75
2026-08-24-3.47
2026-08-23-2.38
2026-08-22-4.80
2026-08-21-6.39
2026-08-20-6.30
2026-08-19-6.01
2026-08-18-0.82
2026-08-17-2.72
2026-08-16-3.14
2026-08-15-3.43
2026-08-14-2.85
2026-08-13-5.52
2026-08-12-3.78
2026-08-11-2.91
2026-08-10-6.09
2026-08-09-4.34
2026-08-08-4.91
2026-08-07-4.62
2026-08-06-4.62
2026-08-05-7.32
2026-08-04-3.15
2026-08-03-3.93
2026-08-02-7.12

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KATL, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 2 days-7 to -6 °F: 5 days-6 to -5 °F: 1 day-5 to -4 °F: 7 days-4 to -3 °F: 7 days-3 to -2 °F: 6 days-2 to -1 °F: 0 days-1 to 0 °F: 1 day0 to 1 °F: 0 days1 to 2 °F: 0 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 4.34 · P90 |e| 6.32 °F-100+10 °Fn = 29 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
-8.00-7.002
-7.00-6.005
-6.00-5.001
-5.00-4.007
-4.00-3.007
-3.00-2.006
-2.00-1.000
-1.00+0.001
+0.00+1.000
+1.00+2.000
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08294.31 -4.31

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF AIFS Single has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
Aurora (GFS init) 1 -3.27 [-3.27, -3.27] yes
Aurora (IFS init) 2 -2.11 [-2.36, -1.87] yes
FourCastNet v2 (GFS init) 1 +0.40 [0.40, 0.40] yes
FourCastNet v2 (IFS init) 2 +1.37 [1.22, 1.52] yes
NCEP GFS 29 +1.86 [0.77, 2.71] yes
GraphCast (GFS init) 1 -2.35 [-2.35, -2.35] yes
GraphCast (IFS init) 27 -1.62 [-2.27, -1.00] yes
ECMWF IFS HRES 23 +2.11 [1.26, 2.83] yes
Pangu-Weather (GFS init) 1 -0.15 [-0.15, -0.15] yes
Pangu-Weather (IFS init) 2 +1.29 [0.85, 1.72] yes
Persistence (baseline) 29 +2.10 [1.46, 2.78] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KATL (Atlanta Hartsfield), model aifs_single, 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/KATL/model/aifs_single/lead/1/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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