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 2

KATL · ifs_hres · lead 2

Target day = initialization date + 2 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 QC2.57 [2.08, 3.33]2.25-1.55 [-3.16, -0.36]3.20 [2.47, 3.94]18% [0%, 35%]41%64%-0.15-0.012026-08-03 → 2026-08-30
tmax00Zbilinear90d22 1 QC2.57 [2.04, 3.59]2.25-1.55 [-3.54, -0.35]3.20 [2.39, 4.06]18% [0%, 36%]41%64%-0.15-0.012026-08-03 → 2026-08-30
tmax00Zbilinear365d22 1 QC2.57 [1.99, 3.59]2.25-1.55 [-3.53, -0.13]3.20 [2.28, 4.07]18% [0%, 38%]41%64%-0.15-0.012026-08-03 → 2026-08-30
tmax00Zbilinearall22 1 QC2.57 [1.96, 3.54]2.25-1.55 [-3.54, -0.35]3.20 [2.11, 4.05]18% [0%, 37%]41%64%-0.15-0.012026-08-03 → 2026-08-30
tmax00Znearest30d22 1 QC2.61 [2.15, 3.36]2.28-1.21 [-2.97, 0.13]3.09 [2.63, 3.71]18% [6%, 29%]36%64%-0.17-0.022026-08-03 → 2026-08-30
tmax00Znearest90d22 1 QC2.61 [2.10, 3.49]2.28-1.21 [-3.44, 0.16]3.09 [2.52, 3.80]18% [0%, 29%]36%64%-0.17-0.022026-08-03 → 2026-08-30
tmax00Znearest365d22 1 QC2.61 [2.04, 3.42]2.28-1.21 [-3.42, 0.31]3.09 [2.50, 3.77]18% [0%, 29%]36%64%-0.17-0.022026-08-03 → 2026-08-30
tmax00Znearestall22 1 QC2.61 [2.09, 3.55]2.28-1.21 [-3.55, 0.14]3.09 [2.49, 3.84]18% [0%, 29%]36%64%-0.17-0.022026-08-03 → 2026-08-30
tmax12Zbilinear30d22 1 QC2.76 [1.57, 4.30]2.04-2.40 [-4.29, -0.88]3.47 [1.88, 4.79]18% [0%, 33%]50%64%-0.27+0.062026-08-03 → 2026-08-30
tmax12Zbilinear90d22 1 QC2.76 [1.53, 4.76]2.04-2.40 [-4.75, -0.79]3.47 [1.81, 5.09]18% [0%, 34%]50%64%-0.27+0.062026-08-03 → 2026-08-30
tmax12Zbilinear365d22 1 QC2.76 [1.42, 4.76]2.04-2.40 [-4.76, -0.59]3.47 [1.64, 5.06]18% [0%, 35%]50%64%-0.27+0.062026-08-03 → 2026-08-30
tmax12Zbilinearall22 1 QC2.76 [1.46, 4.69]2.04-2.40 [-4.69, -0.79]3.47 [1.70, 5.02]18% [0%, 33%]50%64%-0.27+0.062026-08-03 → 2026-08-30
tmax12Znearest30d22 1 QC2.53 [1.44, 4.12]2.13-2.09 [-4.07, -0.60]3.35 [1.82, 4.76]27% [7%, 41%]55%68%-0.16+0.022026-08-03 → 2026-08-30
tmax12Znearest90d22 1 QC2.53 [1.39, 4.59]2.13-2.09 [-4.59, -0.53]3.35 [1.73, 5.03]27% [0%, 42%]55%68%-0.16+0.022026-08-03 → 2026-08-30
tmax12Znearest365d22 1 QC2.53 [1.28, 4.57]2.13-2.09 [-4.57, -0.36]3.35 [1.61, 5.03]27% [0%, 43%]55%68%-0.16+0.022026-08-03 → 2026-08-30
tmax12Znearestall22 1 QC2.53 [1.36, 4.60]2.13-2.09 [-4.60, -0.59]3.35 [1.69, 5.03]27% [0%, 42%]55%68%-0.16+0.022026-08-03 → 2026-08-30
tmin00Zbilinear30d22 1 QC2.05 [1.59, 2.40]2.05+0.22 [-0.85, 1.40]2.47 [1.87, 2.82]32% [21%, 42%]45%77%+0.08+0.092026-08-03 → 2026-08-30
tmin00Zbilinear90d22 1 QC2.05 [1.53, 2.39]2.05+0.22 [-1.00, 1.54]2.47 [1.75, 2.82]32% [18%, 43%]45%77%+0.08+0.092026-08-03 → 2026-08-30
tmin00Zbilinear365d22 1 QC2.05 [1.55, 2.43]2.05+0.22 [-1.14, 1.73]2.47 [1.75, 2.84]32% [20%, 43%]45%77%+0.08+0.092026-08-03 → 2026-08-30
tmin00Zbilinearall22 1 QC2.05 [1.56, 2.39]2.05+0.22 [-1.02, 1.57]2.47 [1.73, 2.82]32% [18%, 43%]45%77%+0.08+0.092026-08-03 → 2026-08-30
tmin00Znearest30d22 1 QC2.13 [1.66, 2.45]2.10+0.38 [-0.61, 1.52]2.55 [1.91, 2.92]27% [17%, 40%]55%73%+0.04+0.062026-08-03 → 2026-08-30
tmin00Znearest90d22 1 QC2.13 [1.58, 2.47]2.10+0.38 [-0.74, 1.65]2.55 [1.77, 2.93]27% [14%, 40%]55%73%+0.04+0.062026-08-03 → 2026-08-30
tmin00Znearest365d22 1 QC2.13 [1.58, 2.49]2.10+0.38 [-0.82, 1.86]2.55 [1.81, 2.97]27% [15%, 41%]55%73%+0.04+0.062026-08-03 → 2026-08-30
tmin00Znearestall22 1 QC2.13 [1.58, 2.46]2.10+0.38 [-0.69, 1.69]2.55 [1.79, 2.94]27% [15%, 40%]55%73%+0.04+0.062026-08-03 → 2026-08-30
tmin12Zbilinear30d22 1 QC1.85 [1.47, 2.26]1.85-0.09 [-1.13, 1.09]2.38 [1.89, 2.77]36% [23%, 50%]68%77%+0.18+0.182026-08-03 → 2026-08-30
tmin12Zbilinear90d22 1 QC1.85 [1.44, 2.20]1.85-0.09 [-1.21, 1.19]2.38 [1.84, 2.71]36% [20%, 50%]68%77%+0.18+0.182026-08-03 → 2026-08-30
tmin12Zbilinear365d22 1 QC1.85 [1.45, 2.31]1.85-0.09 [-1.32, 1.36]2.38 [1.84, 2.81]36% [20%, 50%]68%77%+0.18+0.182026-08-03 → 2026-08-30
tmin12Zbilinearall22 1 QC1.85 [1.42, 2.26]1.85-0.09 [-1.20, 1.23]2.38 [1.78, 2.75]36% [18%, 50%]68%77%+0.18+0.182026-08-03 → 2026-08-30
tmin12Znearest30d22 1 QC1.85 [1.41, 2.27]1.87-0.17 [-1.21, 1.02]2.48 [1.97, 2.89]41% [24%, 54%]68%73%+0.19+0.182026-08-03 → 2026-08-30
tmin12Znearest90d22 1 QC1.85 [1.40, 2.20]1.87-0.17 [-1.31, 1.13]2.48 [1.89, 2.80]41% [22%, 55%]68%73%+0.19+0.182026-08-03 → 2026-08-30
tmin12Znearest365d22 1 QC1.85 [1.39, 2.32]1.87-0.17 [-1.44, 1.32]2.48 [1.92, 2.91]41% [21%, 56%]68%73%+0.19+0.182026-08-03 → 2026-08-30
tmin12Znearestall22 1 QC1.85 [1.34, 2.27]1.87-0.17 [-1.30, 1.18]2.48 [1.81, 2.85]41% [20%, 57%]68%73%+0.19+0.182026-08-03 → 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 2, 00Z bilinear tmax+10+50-5-102026-08-03: -2.04 °F2026-08-08: -3.97 °F2026-08-09: -4.62 °F2026-08-11: -3.14 °F2026-08-13: -0.87 °F2026-08-14: +0.11 °F2026-08-15: -7.64 °F2026-08-16: -2.68 °F2026-08-17: -0.13 °F2026-08-18: +4.36 °F2026-08-19: +1.4 °F2026-08-20: +2.01 °F2026-08-21: +1.97 °F2026-08-22: -3.64 °F2026-08-23: -2.29 °F2026-08-24: -1.22 °F2026-08-25: -1.22 °F2026-08-26: +1.29 °F2026-08-27: +0.02 °F2026-08-28: -3.03 °F2026-08-29: -2.49 °F2026-08-30: -6.33 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-6.33
2026-08-29-2.49
2026-08-28-3.03
2026-08-27+0.02
2026-08-26+1.29
2026-08-25-1.22
2026-08-24-1.22
2026-08-23-2.29
2026-08-22-3.64
2026-08-21+1.97
2026-08-20+2.01
2026-08-19+1.40
2026-08-18+4.36
2026-08-17-0.13
2026-08-16-2.68
2026-08-15-7.64
2026-08-14+0.11
2026-08-13-0.87
2026-08-12—
2026-08-11-3.14
2026-08-10—
2026-08-09-4.62
2026-08-08-3.97
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03-2.04

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KATL, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 1 day-4 to -3 °F: 4 days-3 to -2 °F: 4 days-2 to -1 °F: 2 days-1 to 0 °F: 2 days0 to 1 °F: 2 days1 to 2 °F: 3 days2 to 3 °F: 1 day3 to 4 °F: 0 days4 to 5 °F: 1 day5 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| 2.16 · P90 |e| 4.59 °F-100+10 °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
-10.00-9.000
-9.00-8.000
-8.00-7.001
-7.00-6.001
-6.00-5.000
-5.00-4.001
-4.00-3.004
-3.00-2.004
-2.00-1.002
-1.00+0.002
+0.00+1.002
+1.00+2.003
+2.00+3.001
+3.00+4.000
+4.00+5.001
+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
2026-08222.57 -1.55

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 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 -1.75 [-2.69, -0.64] yes
Aurora (IFS init) 1 -1.18 [-1.18, -1.18] yes
FourCastNet v2 (IFS init) 1 +1.70 [1.70, 1.70] yes
NCEP GFS 22 -0.35 [-1.57, 2.20] no
GraphCast (IFS init) 20 -3.11 [-4.22, -2.06] yes
Pangu-Weather (IFS init) 1 +1.62 [1.62, 1.62] yes
Persistence (baseline) 22 +0.34 [-0.20, 1.35] no

Cite this page

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

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

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