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

Atlanta Hartsfield · ECMWF AIFS Single · lead day 6

KATL · aifs_single · 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, 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
tmax00Zbilinear30d24 1 QC4.89 [3.90, 5.77]2.17-4.68 [-5.76, -3.43]5.48 [4.36, 6.34]4% [0%, 11%]17%29%-0.58+0.312026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC4.89 [3.80, 5.89]2.17-4.68 [-5.89, -3.30]5.48 [4.18, 6.41]4% [0%, 12%]17%29%-0.58+0.312026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC4.89 [3.61, 5.88]2.17-4.68 [-5.88, -3.12]5.48 [3.99, 6.42]4% [0%, 14%]17%29%-0.58+0.312026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC4.89 [3.61, 5.86]2.17-4.68 [-5.86, -3.20]5.48 [3.98, 6.40]4% [0%, 14%]17%29%-0.58+0.312026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC4.97 [3.95, 5.87]2.16-4.79 [-5.86, -3.55]5.55 [4.42, 6.38]4% [0%, 11%]8%29%-0.61+0.312026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC4.97 [3.88, 5.98]2.16-4.79 [-5.98, -3.43]5.55 [4.22, 6.46]4% [0%, 12%]8%29%-0.61+0.312026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC4.97 [3.64, 5.98]2.16-4.79 [-5.98, -3.25]5.55 [4.04, 6.46]4% [0%, 14%]8%29%-0.61+0.312026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC4.97 [3.70, 5.98]2.16-4.79 [-5.98, -3.30]5.55 [4.05, 6.45]4% [0%, 14%]8%29%-0.61+0.312026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC4.79 [3.94, 5.50]1.91-4.70 [-5.49, -3.78]5.33 [4.47, 6.04]8% [0%, 18%]12%17%-0.55+0.392026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC4.79 [3.88, 5.57]1.91-4.70 [-5.56, -3.70]5.33 [4.41, 6.06]8% [0%, 18%]12%17%-0.55+0.392026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC4.79 [3.78, 5.56]1.91-4.70 [-5.56, -3.55]5.33 [4.33, 6.06]8% [0%, 20%]12%17%-0.55+0.392026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC4.79 [3.69, 5.60]1.91-4.70 [-5.59, -3.53]5.33 [4.17, 6.08]8% [0%, 19%]12%17%-0.55+0.392026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC4.93 [4.01, 5.69]1.98-4.88 [-5.69, -3.93]5.50 [4.60, 6.22]8% [0%, 18%]12%17%-0.60+0.372026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC4.93 [3.94, 5.77]1.98-4.88 [-5.76, -3.85]5.50 [4.50, 6.24]8% [0%, 18%]12%17%-0.60+0.372026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC4.93 [3.82, 5.77]1.98-4.88 [-5.75, -3.69]5.50 [4.45, 6.24]8% [0%, 20%]12%17%-0.60+0.372026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC4.93 [3.74, 5.78]1.98-4.88 [-5.78, -3.67]5.50 [4.26, 6.26]8% [0%, 19%]12%17%-0.60+0.372026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC1.71 [1.16, 2.18]1.71-0.01 [-0.60, 0.65]2.08 [1.36, 2.57]29% [20%, 45%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC1.71 [1.01, 2.17]1.71-0.01 [-0.62, 0.64]2.08 [1.15, 2.55]29% [19%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC1.71 [0.98, 2.24]1.71-0.01 [-0.73, 0.69]2.08 [1.12, 2.62]29% [18%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC1.71 [0.88, 2.21]1.71-0.01 [-0.66, 0.64]2.08 [1.00, 2.57]29% [14%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC1.72 [1.19, 2.18]1.72-0.08 [-0.69, 0.60]2.07 [1.40, 2.55]25% [13%, 44%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC1.72 [1.02, 2.17]1.72-0.08 [-0.74, 0.59]2.07 [1.18, 2.53]25% [12%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC1.72 [0.99, 2.24]1.72-0.08 [-0.82, 0.64]2.07 [1.14, 2.59]25% [11%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC1.72 [0.92, 2.19]1.72-0.08 [-0.77, 0.59]2.07 [1.07, 2.54]25% [13%, 50%]71%88%+0.28+0.282026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC1.79 [1.16, 2.29]1.79-0.15 [-0.93, 0.60]2.20 [1.55, 2.61]25% [10%, 43%]67%79%+0.25+0.252026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC1.79 [0.94, 2.29]1.79-0.15 [-0.99, 0.64]2.20 [1.17, 2.62]25% [7%, 45%]67%79%+0.25+0.252026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC1.79 [0.93, 2.30]1.79-0.15 [-1.13, 0.66]2.20 [1.16, 2.64]25% [7%, 47%]67%79%+0.25+0.252026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC1.79 [0.94, 2.33]1.79-0.15 [-1.11, 0.63]2.20 [1.16, 2.65]25% [5%, 45%]67%79%+0.25+0.252026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC1.80 [1.16, 2.28]1.79-0.21 [-0.98, 0.53]2.19 [1.55, 2.60]25% [10%, 42%]71%75%+0.24+0.252026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC1.80 [1.00, 2.29]1.79-0.21 [-1.05, 0.57]2.19 [1.21, 2.59]25% [8%, 44%]71%75%+0.24+0.252026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC1.80 [0.96, 2.29]1.79-0.21 [-1.15, 0.58]2.19 [1.20, 2.62]25% [9%, 44%]71%75%+0.24+0.252026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC1.80 [0.97, 2.33]1.79-0.21 [-1.14, 0.55]2.19 [1.19, 2.63]25% [6%, 45%]71%75%+0.24+0.252026-08-07 → 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 AIFS Single at KATL, lead day 6, 00Z bilinear tmax+10+50-5-102026-08-07: -1.95 °F2026-08-08: -4.85 °F2026-08-09: -5.23 °F2026-08-10: -8.81 °F2026-08-11: -7.2 °F2026-08-12: -6.71 °F2026-08-13: -5.81 °F2026-08-14: -4.66 °F2026-08-15: -4.7 °F2026-08-16: -2.82 °F2026-08-17: -3.88 °F2026-08-18: +2.47 °F2026-08-19: -5.25 °F2026-08-20: -6.05 °F2026-08-21: -1.89 °F2026-08-22: -2.93 °F2026-08-23: -0.24 °F2026-08-24: -5.06 °F2026-08-25: -9.78 °F2026-08-26: -3.01 °F2026-08-27: -8.08 °F2026-08-28: -9.31 °F2026-08-29: -1.9 °F2026-08-30: -4.68 °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
2026-08-30-4.68
2026-08-29-1.90
2026-08-28-9.31
2026-08-27-8.08
2026-08-26-3.01
2026-08-25-9.78
2026-08-24-5.06
2026-08-23-0.24
2026-08-22-2.93
2026-08-21-1.89
2026-08-20-6.05
2026-08-19-5.25
2026-08-18+2.47
2026-08-17-3.88
2026-08-16-2.82
2026-08-15-4.70
2026-08-14-4.66
2026-08-13-5.81
2026-08-12-6.71
2026-08-11-7.20
2026-08-10-8.81
2026-08-09-5.23
2026-08-08-4.85
2026-08-07-1.95

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KATL, lead day 6-10 to -9 °F: 2 days-9 to -8 °F: 2 days-8 to -7 °F: 1 day-7 to -6 °F: 2 days-6 to -5 °F: 4 days-5 to -4 °F: 4 days-4 to -3 °F: 2 days-3 to -2 °F: 2 days-2 to -1 °F: 3 days-1 to 0 °F: 1 day0 to 1 °F: 0 days1 to 2 °F: 0 days2 to 3 °F: 1 day3 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| 4.77 · P90 |e| 8.59 °F-100+10 °Fn = 24 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
-9.00-8.002
-8.00-7.001
-7.00-6.002
-6.00-5.004
-5.00-4.004
-4.00-3.002
-3.00-2.002
-2.00-1.003
-1.00+0.001
+0.00+1.000
+1.00+2.000
+2.00+3.001
+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
2026-08244.89 -4.68

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24

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
NCEP GFS 24 -0.03 [-1.28, 1.39] no
GraphCast (IFS init) 24 -0.46 [-2.08, 0.52] no
ECMWF IFS HRES 19 +1.32 [-0.51, 2.35] no
Persistence (baseline) 24 +1.80 [1.15, 2.74] yes

Cite this page

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

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