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 IFS HRES · lead day 1

KATL · ifs_hres · 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, 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
tmax00Zbilinear30d23 1 QC2.08 [1.37, 3.23]1.66-1.53 [-2.89, -0.56]2.57 [1.73, 3.61]30% [6%, 52%]48%78%-0.04+0.172026-08-02 → 2026-08-30
tmax00Zbilinear90d23 1 QC2.08 [1.42, 3.85]1.66-1.53 [-3.78, -0.64]2.57 [1.84, 4.24]30% [0%, 53%]48%78%-0.04+0.172026-08-02 → 2026-08-30
tmax00Zbilinear365d23 1 QC2.08 [1.38, 3.69]1.66-1.53 [-3.65, -0.56]2.57 [1.71, 4.00]30% [0%, 54%]48%78%-0.04+0.172026-08-02 → 2026-08-30
tmax00Zbilinearall23 1 QC2.08 [1.42, 4.14]1.66-1.53 [-4.14, -0.66]2.57 [1.81, 4.34]30% [0%, 52%]48%78%-0.04+0.172026-08-02 → 2026-08-30
tmax00Znearest30d23 1 QC2.10 [1.42, 3.09]1.84-1.24 [-2.60, -0.27]2.51 [1.79, 3.44]22% [0%, 38%]48%78%-0.05+0.082026-08-02 → 2026-08-30
tmax00Znearest90d23 1 QC2.10 [1.45, 3.66]1.84-1.24 [-3.52, -0.26]2.51 [1.86, 3.99]22% [0%, 40%]48%78%-0.05+0.082026-08-02 → 2026-08-30
tmax00Znearest365d23 1 QC2.10 [1.42, 3.49]1.84-1.24 [-3.41, -0.23]2.51 [1.80, 3.80]22% [0%, 38%]48%78%-0.05+0.082026-08-02 → 2026-08-30
tmax00Znearestall23 1 QC2.10 [1.47, 3.66]1.84-1.24 [-3.65, -0.35]2.51 [1.80, 3.99]22% [0%, 38%]48%78%-0.05+0.082026-08-02 → 2026-08-30
tmax12Zbilinear30d24 1 QC2.85 [1.93, 4.09]1.59-2.82 [-4.09, -1.89]3.44 [2.47, 4.51]21% [5%, 36%]42%62%-0.34+0.252026-08-02 → 2026-08-30
tmax12Zbilinear90d24 1 QC2.85 [1.96, 4.71]1.59-2.82 [-4.71, -1.90]3.44 [2.54, 5.04]21% [0%, 36%]42%62%-0.34+0.252026-08-02 → 2026-08-30
tmax12Zbilinear365d24 1 QC2.85 [1.89, 4.40]1.59-2.82 [-4.40, -1.83]3.44 [2.45, 4.90]21% [0%, 38%]42%62%-0.34+0.252026-08-02 → 2026-08-30
tmax12Zbilinearall24 1 QC2.85 [1.88, 4.58]1.59-2.82 [-4.58, -1.80]3.44 [2.41, 5.04]21% [0%, 36%]42%62%-0.34+0.252026-08-02 → 2026-08-30
tmax12Znearest30d24 1 QC2.54 [1.74, 3.67]1.62-2.46 [-3.67, -1.58]3.15 [2.31, 4.12]21% [5%, 36%]54%67%-0.19+0.242026-08-02 → 2026-08-30
tmax12Znearest90d24 1 QC2.54 [1.76, 4.14]1.62-2.46 [-4.14, -1.59]3.15 [2.30, 4.65]21% [0%, 36%]54%67%-0.19+0.242026-08-02 → 2026-08-30
tmax12Znearest365d24 1 QC2.54 [1.69, 3.98]1.62-2.46 [-3.98, -1.55]3.15 [2.19, 4.46]21% [0%, 38%]54%67%-0.19+0.242026-08-02 → 2026-08-30
tmax12Znearestall24 1 QC2.54 [1.66, 4.21]1.62-2.46 [-4.21, -1.48]3.15 [2.16, 4.73]21% [0%, 36%]54%67%-0.19+0.242026-08-02 → 2026-08-30
tmin00Zbilinear30d23 1 QC1.93 [1.54, 2.23]1.92+0.19 [-0.97, 1.33]2.27 [1.84, 2.62]22% [10%, 38%]61%78%+0.04+0.032026-08-02 → 2026-08-30
tmin00Zbilinear90d23 1 QC1.93 [1.30, 2.22]1.92+0.19 [-1.27, 1.32]2.27 [1.68, 2.61]22% [8%, 50%]61%78%+0.04+0.032026-08-02 → 2026-08-30
tmin00Zbilinear365d23 1 QC1.93 [1.41, 2.28]1.92+0.19 [-1.36, 1.43]2.27 [1.66, 2.63]22% [7%, 44%]61%78%+0.04+0.032026-08-02 → 2026-08-30
tmin00Zbilinearall23 1 QC1.93 [1.36, 2.25]1.92+0.19 [-1.23, 1.35]2.27 [1.63, 2.62]22% [7%, 50%]61%78%+0.04+0.032026-08-02 → 2026-08-30
tmin00Znearest30d23 1 QC1.89 [1.55, 2.17]1.86+0.21 [-0.84, 1.22]2.18 [1.80, 2.50]22% [10%, 38%]61%83%+0.06+0.062026-08-02 → 2026-08-30
tmin00Znearest90d23 1 QC1.89 [1.34, 2.14]1.86+0.21 [-1.06, 1.25]2.18 [1.65, 2.48]22% [8%, 50%]61%83%+0.06+0.062026-08-02 → 2026-08-30
tmin00Znearest365d23 1 QC1.89 [1.49, 2.19]1.86+0.21 [-1.15, 1.34]2.18 [1.67, 2.53]22% [7%, 44%]61%83%+0.06+0.062026-08-02 → 2026-08-30
tmin00Znearestall23 1 QC1.89 [1.42, 2.16]1.86+0.21 [-1.01, 1.24]2.18 [1.63, 2.50]22% [7%, 50%]61%83%+0.06+0.062026-08-02 → 2026-08-30
tmin12Zbilinear30d24 1 QC1.58 [1.10, 2.03]1.54-0.29 [-1.16, 0.59]1.96 [1.40, 2.39]50% [29%, 73%]62%88%+0.19+0.212026-08-02 → 2026-08-30
tmin12Zbilinear90d24 1 QC1.58 [0.99, 2.04]1.54-0.29 [-1.43, 0.60]1.96 [1.29, 2.39]50% [26%, 75%]62%88%+0.19+0.212026-08-02 → 2026-08-30
tmin12Zbilinear365d24 1 QC1.58 [0.92, 2.09]1.54-0.29 [-1.43, 0.71]1.96 [1.21, 2.41]50% [25%, 78%]62%88%+0.19+0.212026-08-02 → 2026-08-30
tmin12Zbilinearall24 1 QC1.58 [0.89, 2.07]1.54-0.29 [-1.42, 0.59]1.96 [1.18, 2.42]50% [26%, 86%]62%88%+0.19+0.212026-08-02 → 2026-08-30
tmin12Znearest30d24 1 QC1.60 [1.16, 2.00]1.54-0.46 [-1.32, 0.46]1.97 [1.46, 2.38]42% [26%, 60%]67%88%+0.18+0.212026-08-02 → 2026-08-30
tmin12Znearest90d24 1 QC1.60 [1.10, 2.00]1.54-0.46 [-1.54, 0.44]1.97 [1.36, 2.39]42% [22%, 64%]67%88%+0.18+0.212026-08-02 → 2026-08-30
tmin12Znearest365d24 1 QC1.60 [1.00, 2.03]1.54-0.46 [-1.55, 0.57]1.97 [1.28, 2.41]42% [18%, 67%]67%88%+0.18+0.212026-08-02 → 2026-08-30
tmin12Znearestall24 1 QC1.60 [0.97, 2.03]1.54-0.46 [-1.54, 0.44]1.97 [1.22, 2.40]42% [20%, 71%]67%88%+0.18+0.212026-08-02 → 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 IFS HRES at KATL, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -6.09 °F2026-08-09: -2.08 °F2026-08-10: -4.71 °F2026-08-11: -1.6 °F2026-08-12: -2.76 °F2026-08-13: -2.13 °F2026-08-14: +0.8 °F2026-08-15: -0.88 °F2026-08-16: +0.87 °F2026-08-17: -0.35 °F2026-08-18: +2.09 °F2026-08-19: -1.36 °F2026-08-20: +0.14 °F2026-08-21: -0.28 °F2026-08-22: -3.46 °F2026-08-23: -2.14 °F2026-08-24: -1.97 °F2026-08-25: -1.28 °F2026-08-26: +0.36 °F2026-08-27: +2.11 °F2026-08-28: -4.11 °F2026-08-29: -3.87 °F2026-08-30: -2.5 °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
2026-08-30-2.50
2026-08-29-3.87
2026-08-28-4.11
2026-08-27+2.11
2026-08-26+0.36
2026-08-25-1.28
2026-08-24-1.97
2026-08-23-2.14
2026-08-22-3.46
2026-08-21-0.28
2026-08-20+0.14
2026-08-19-1.36
2026-08-18+2.09
2026-08-17-0.35
2026-08-16+0.87
2026-08-15-0.88
2026-08-14+0.80
2026-08-13-2.13
2026-08-12-2.76
2026-08-11-1.60
2026-08-10-4.71
2026-08-09-2.08
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02-6.09

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KATL, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 2 days-4 to -3 °F: 2 days-3 to -2 °F: 5 days-2 to -1 °F: 4 days-1 to 0 °F: 3 days0 to 1 °F: 4 days1 to 2 °F: 0 days2 to 3 °F: 2 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| 2.08 · P90 |e| 4.06 °F-100+10 °Fn = 23 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
-8.00-7.000
-7.00-6.001
-6.00-5.000
-5.00-4.002
-4.00-3.002
-3.00-2.005
-2.00-1.004
-1.00+0.003
+0.00+1.004
+1.00+2.000
+2.00+3.002
+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
2026-08232.08 -1.53

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-02 → 2026-08-30 23
ECMWF IFS HRES2026-08-02 → 2026-08-30 23
ECMWF IFS HRES2026-08-02 → 2026-08-30 24
ECMWF IFS HRES2026-08-02 → 2026-08-30 24

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 23 -2.11 [-2.83, -1.26] yes
Aurora (GFS init) 1 -4.61 [-4.61, -4.61] yes
Aurora (IFS init) 2 -3.07 [-3.69, -2.45] yes
FourCastNet v2 (GFS init) 1 -0.94 [-0.94, -0.94] yes
FourCastNet v2 (IFS init) 2 +0.41 [-0.12, 0.94] no
NCEP GFS 23 -0.61 [-2.08, 0.30] no
GraphCast (GFS init) 1 -3.69 [-3.69, -3.69] yes
GraphCast (IFS init) 21 -3.92 [-4.48, -2.99] yes
Pangu-Weather (GFS init) 1 -1.48 [-1.48, -1.48] yes
Pangu-Weather (IFS init) 2 +0.33 [-0.48, 1.14] no
Persistence (baseline) 23 +0.08 [-0.78, 1.28] no

Cite this page

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

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

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