Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

Atlanta Hartsfield · ECMWF AIFS Single · lead day 3

KATL · aifs_single · 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, 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
tmax00Zbilinear30d27 1 QC4.30 [3.64, 4.80]1.46-4.30 [-4.80, -3.64]4.71 [4.05, 5.20]4% [0%, 11%]7%19%-1.19+0.262026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC4.30 [3.65, 4.89]1.46-4.30 [-4.89, -3.65]4.71 [4.04, 5.36]4% [0%, 11%]7%19%-1.19+0.262026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC4.30 [3.54, 4.85]1.46-4.30 [-4.85, -3.54]4.71 [3.94, 5.27]4% [0%, 11%]7%19%-1.19+0.262026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC4.30 [3.57, 4.82]1.46-4.30 [-4.82, -3.57]4.71 [3.96, 5.31]4% [0%, 11%]7%19%-1.19+0.262026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC4.43 [3.77, 4.93]1.49-4.43 [-4.93, -3.77]4.84 [4.17, 5.30]4% [0%, 11%]7%22%-1.26+0.242026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC4.43 [3.77, 5.00]1.49-4.43 [-5.00, -3.77]4.84 [4.15, 5.42]4% [0%, 11%]7%22%-1.26+0.242026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC4.43 [3.67, 4.98]1.49-4.43 [-4.98, -3.67]4.84 [4.05, 5.38]4% [0%, 11%]7%22%-1.26+0.242026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC4.43 [3.68, 4.98]1.49-4.43 [-4.98, -3.68]4.84 [4.08, 5.36]4% [0%, 11%]7%22%-1.26+0.242026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC4.34 [3.75, 4.81]1.33-4.34 [-4.81, -3.75]4.68 [4.08, 5.11]0% [0%, 0%]11%19%-1.21+0.332026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC4.34 [3.74, 4.89]1.33-4.34 [-4.89, -3.74]4.68 [4.09, 5.17]0% [0%, 0%]11%19%-1.21+0.332026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC4.34 [3.63, 4.87]1.33-4.34 [-4.87, -3.63]4.68 [3.95, 5.17]0% [0%, 0%]11%19%-1.21+0.332026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC4.34 [3.63, 4.87]1.33-4.34 [-4.87, -3.63]4.68 [3.99, 5.14]0% [0%, 0%]11%19%-1.21+0.332026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC4.47 [3.87, 4.93]1.36-4.47 [-4.93, -3.87]4.80 [4.20, 5.22]0% [0%, 0%]11%19%-1.28+0.312026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC4.47 [3.85, 4.97]1.36-4.47 [-4.97, -3.85]4.80 [4.20, 5.25]0% [0%, 0%]11%19%-1.28+0.312026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC4.47 [3.76, 4.97]1.36-4.47 [-4.97, -3.76]4.80 [4.05, 5.27]0% [0%, 0%]11%19%-1.28+0.312026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC4.47 [3.76, 4.98]1.36-4.47 [-4.98, -3.76]4.80 [4.09, 5.26]0% [0%, 0%]11%19%-1.28+0.312026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.70 [0.95, 2.29]1.68-0.46 [-1.60, 0.42]2.23 [1.34, 2.83]33% [16%, 58%]63%85%+0.12+0.132026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.70 [0.80, 2.28]1.68-0.46 [-1.69, 0.46]2.23 [1.08, 2.81]33% [15%, 64%]63%85%+0.12+0.132026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC1.70 [0.79, 2.34]1.68-0.46 [-1.93, 0.48]2.23 [1.08, 2.88]33% [14%, 63%]63%85%+0.12+0.132026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC1.70 [0.72, 2.37]1.68-0.46 [-1.91, 0.48]2.23 [0.99, 2.89]33% [14%, 67%]63%85%+0.12+0.132026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC1.73 [0.96, 2.34]1.68-0.55 [-1.70, 0.35]2.25 [1.34, 2.89]30% [10%, 57%]63%85%+0.10+0.132026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC1.73 [0.79, 2.32]1.68-0.55 [-1.80, 0.37]2.25 [1.08, 2.86]30% [10%, 62%]63%85%+0.10+0.132026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC1.73 [0.79, 2.39]1.68-0.55 [-2.05, 0.39]2.25 [1.06, 2.96]30% [9%, 63%]63%85%+0.10+0.132026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC1.73 [0.73, 2.43]1.68-0.55 [-2.04, 0.39]2.25 [1.00, 2.96]30% [9%, 67%]63%85%+0.10+0.132026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.83 [1.09, 2.38]1.82-0.36 [-1.52, 0.55]2.28 [1.46, 2.78]37% [20%, 61%]56%81%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.83 [0.90, 2.35]1.82-0.36 [-1.61, 0.57]2.28 [1.19, 2.75]37% [21%, 67%]56%81%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC1.83 [0.97, 2.39]1.82-0.36 [-1.83, 0.60]2.28 [1.22, 2.78]37% [20%, 67%]56%81%+0.05+0.052026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC1.83 [0.84, 2.45]1.82-0.36 [-1.80, 0.60]2.28 [1.08, 2.83]37% [19%, 73%]56%81%+0.05+0.052026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC1.84 [1.08, 2.43]1.83-0.44 [-1.63, 0.48]2.30 [1.45, 2.85]33% [16%, 58%]56%81%+0.04+0.052026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC1.84 [0.90, 2.39]1.83-0.44 [-1.70, 0.48]2.30 [1.21, 2.81]33% [15%, 64%]56%81%+0.04+0.052026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC1.84 [0.95, 2.44]1.83-0.44 [-1.94, 0.52]2.30 [1.23, 2.87]33% [14%, 63%]56%81%+0.04+0.052026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC1.84 [0.83, 2.50]1.83-0.44 [-1.92, 0.52]2.30 [1.09, 2.90]33% [14%, 67%]56%81%+0.04+0.052026-08-04 → 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 AIFS Single at KATL, lead day 3, 00Z bilinear tmax+10+50-5-102026-08-04: -2.31 °F2026-08-05: -7.33 °F2026-08-06: -3.29 °F2026-08-07: -3.26 °F2026-08-08: -5.34 °F2026-08-09: -3.91 °F2026-08-10: -6.78 °F2026-08-11: -4.84 °F2026-08-12: -4.98 °F2026-08-13: -3.92 °F2026-08-14: -2.7 °F2026-08-15: -3.13 °F2026-08-16: -2.34 °F2026-08-17: -3.05 °F2026-08-18: -0.28 °F2026-08-19: -4.96 °F2026-08-20: -7.31 °F2026-08-21: -5.74 °F2026-08-22: -4.4 °F2026-08-23: -3.22 °F2026-08-24: -4.49 °F2026-08-25: -4.24 °F2026-08-26: -1.33 °F2026-08-27: -5.5 °F2026-08-28: -9.59 °F2026-08-29: -3.45 °F2026-08-30: -4.3 °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
2026-08-30-4.30
2026-08-29-3.45
2026-08-28-9.59
2026-08-27-5.50
2026-08-26-1.33
2026-08-25-4.24
2026-08-24-4.49
2026-08-23-3.22
2026-08-22-4.40
2026-08-21-5.74
2026-08-20-7.31
2026-08-19-4.96
2026-08-18-0.28
2026-08-17-3.05
2026-08-16-2.34
2026-08-15-3.13
2026-08-14-2.70
2026-08-13-3.92
2026-08-12-4.98
2026-08-11-4.84
2026-08-10-6.78
2026-08-09-3.91
2026-08-08-5.34
2026-08-07-3.26
2026-08-06-3.29
2026-08-05-7.33
2026-08-04-2.31

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KATL, lead day 3-10 to -9 °F: 1 day-9 to -8 °F: 0 days-8 to -7 °F: 2 days-7 to -6 °F: 1 day-6 to -5 °F: 3 days-5 to -4 °F: 7 days-4 to -3 °F: 8 days-3 to -2 °F: 3 days-2 to -1 °F: 1 day-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| 4.24 · P90 |e| 6.99 °F-100+10 °Fn = 27 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
-8.00-7.002
-7.00-6.001
-6.00-5.003
-5.00-4.007
-4.00-3.008
-3.00-2.003
-2.00-1.001
-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
2026-08274.30 -4.30

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27

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 27 +1.36 [0.27, 2.66] yes
GraphCast (IFS init) 25 -1.23 [-2.07, -0.08] yes
ECMWF IFS HRES 22 +0.93 [0.27, 1.75] yes
Persistence (baseline) 27 +2.33 [1.65, 3.23] yes

Cite this page

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

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