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

Atlanta Hartsfield · ECMWF IFS HRES · lead day 5

KATL · ifs_hres · lead 5

Target day = initialization date + 5 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
tmax00Zbilinear30d18 1 QC3.74 [2.08, 5.35]3.68-1.91 [-4.55, 0.77]4.88 [2.33, 6.57]11% [0%, 23%]39%56%-0.32-0.292026-08-06 → 2026-08-30
tmax00Zbilinear90d18 1 QC3.74 [1.69, 5.35]3.68-1.91 [-4.96, 1.27]4.88 [1.76, 6.55]11% [0%, 22%]39%56%-0.32-0.292026-08-06 → 2026-08-30
tmax00Zbilinear365d18 1 QC3.74 [1.69, 5.40]3.68-1.91 [-4.95, 1.41]4.88 [1.69, 6.60]11% [0%, 23%]39%56%-0.32-0.292026-08-06 → 2026-08-30
tmax00Zbilinearall18 1 QC3.74 [1.69, 5.46]3.68-1.91 [-4.96, 1.05]4.88 [1.80, 6.61]11% [0%, 25%]39%56%-0.32-0.292026-08-06 → 2026-08-30
tmax00Znearest30d18 1 QC3.96 [2.20, 5.68]3.99-1.89 [-4.81, 1.11]5.25 [2.62, 7.04]17% [0%, 33%]39%50%-0.40-0.402026-08-06 → 2026-08-30
tmax00Znearest90d18 1 QC3.96 [1.93, 5.66]3.99-1.89 [-5.16, 1.81]5.25 [1.93, 7.03]17% [0%, 33%]39%50%-0.40-0.402026-08-06 → 2026-08-30
tmax00Znearest365d18 1 QC3.96 [1.93, 5.73]3.99-1.89 [-5.19, 1.93]5.25 [1.93, 6.99]17% [0%, 36%]39%50%-0.40-0.402026-08-06 → 2026-08-30
tmax00Znearestall18 1 QC3.96 [1.91, 5.75]3.99-1.89 [-5.34, 1.55]5.25 [1.93, 6.95]17% [0%, 38%]39%50%-0.40-0.402026-08-06 → 2026-08-30
tmax12Zbilinear30d20 1 QC2.69 [1.92, 3.69]2.78-0.84 [-3.36, 1.08]3.51 [2.56, 4.43]25% [7%, 37%]45%70%+0.04+0.022026-08-06 → 2026-08-30
tmax12Zbilinear90d20 1 QC2.69 [1.85, 3.92]2.78-0.84 [-3.85, 1.38]3.51 [2.26, 4.58]25% [0%, 38%]45%70%+0.04+0.022026-08-06 → 2026-08-30
tmax12Zbilinear365d20 1 QC2.69 [1.87, 3.93]2.78-0.84 [-3.88, 1.39]3.51 [2.07, 4.62]25% [0%, 38%]45%70%+0.04+0.022026-08-06 → 2026-08-30
tmax12Zbilinearall20 1 QC2.69 [1.88, 3.92]2.78-0.84 [-3.85, 1.22]3.51 [2.30, 4.56]25% [0%, 39%]45%70%+0.04+0.022026-08-06 → 2026-08-30
tmax12Znearest30d20 1 QC2.72 [2.03, 3.63]2.78-0.64 [-3.26, 1.29]3.48 [2.67, 4.25]30% [7%, 47%]40%65%+0.03+0.012026-08-06 → 2026-08-30
tmax12Znearest90d20 1 QC2.72 [1.94, 3.80]2.78-0.64 [-3.70, 1.58]3.48 [2.63, 4.36]30% [0%, 47%]40%65%+0.03+0.012026-08-06 → 2026-08-30
tmax12Znearest365d20 1 QC2.72 [1.98, 3.81]2.78-0.64 [-3.68, 1.59]3.48 [2.53, 4.41]30% [0%, 50%]40%65%+0.03+0.012026-08-06 → 2026-08-30
tmax12Znearestall20 1 QC2.72 [1.95, 3.78]2.78-0.64 [-3.66, 1.55]3.48 [2.46, 4.33]30% [0%, 50%]40%65%+0.03+0.012026-08-06 → 2026-08-30
tmin00Zbilinear30d18 1 QC2.24 [1.85, 2.75]2.21+0.47 [-0.97, 2.03]2.50 [2.08, 2.94]17% [0%, 25%]39%67%+0.12+0.132026-08-06 → 2026-08-30
tmin00Zbilinear90d18 1 QC2.24 [1.81, 2.82]2.21+0.47 [-1.25, 2.39]2.50 [2.03, 2.99]17% [0%, 25%]39%67%+0.12+0.132026-08-06 → 2026-08-30
tmin00Zbilinear365d18 1 QC2.24 [1.77, 2.83]2.21+0.47 [-1.31, 2.39]2.50 [1.99, 3.00]17% [0%, 25%]39%67%+0.12+0.132026-08-06 → 2026-08-30
tmin00Zbilinearall18 1 QC2.24 [1.78, 2.83]2.21+0.47 [-1.29, 2.39]2.50 [2.00, 3.02]17% [0%, 25%]39%67%+0.12+0.132026-08-06 → 2026-08-30
tmin00Znearest30d18 1 QC2.36 [1.94, 2.85]2.30+0.52 [-0.95, 2.09]2.58 [2.19, 2.98]11% [0%, 23%]28%67%+0.08+0.102026-08-06 → 2026-08-30
tmin00Znearest90d18 1 QC2.36 [1.89, 2.89]2.30+0.52 [-1.26, 2.37]2.58 [2.16, 3.04]11% [0%, 24%]28%67%+0.08+0.102026-08-06 → 2026-08-30
tmin00Znearest365d18 1 QC2.36 [1.88, 2.92]2.30+0.52 [-1.22, 2.45]2.58 [2.15, 3.05]11% [0%, 25%]28%67%+0.08+0.102026-08-06 → 2026-08-30
tmin00Znearestall18 1 QC2.36 [1.88, 2.93]2.30+0.52 [-1.22, 2.33]2.58 [2.14, 3.06]11% [0%, 24%]28%67%+0.08+0.102026-08-06 → 2026-08-30
tmin12Zbilinear30d20 1 QC2.68 [1.48, 3.55]2.55+0.97 [-0.72, 2.47]3.08 [1.68, 3.82]10% [0%, 33%]45%60%-0.05-0.012026-08-06 → 2026-08-30
tmin12Zbilinear90d20 1 QC2.68 [1.24, 3.62]2.55+0.97 [-0.98, 2.70]3.08 [1.44, 3.88]10% [0%, 50%]45%60%-0.05-0.012026-08-06 → 2026-08-30
tmin12Zbilinear365d20 1 QC2.68 [1.29, 3.66]2.55+0.97 [-1.02, 2.78]3.08 [1.45, 3.90]10% [0%, 40%]45%60%-0.05-0.012026-08-06 → 2026-08-30
tmin12Zbilinearall20 1 QC2.68 [1.27, 3.64]2.55+0.97 [-1.05, 2.56]3.08 [1.46, 3.88]10% [0%, 43%]45%60%-0.05-0.012026-08-06 → 2026-08-30
tmin12Znearest30d20 1 QC2.51 [1.13, 3.47]2.38+1.12 [-0.50, 2.55]3.01 [1.36, 3.75]20% [0%, 50%]45%65%+0.01+0.062026-08-06 → 2026-08-30
tmin12Znearest90d20 1 QC2.51 [0.94, 3.57]2.38+1.12 [-0.66, 2.68]3.01 [1.17, 3.85]20% [0%, 60%]45%65%+0.01+0.062026-08-06 → 2026-08-30
tmin12Znearest365d20 1 QC2.51 [0.94, 3.60]2.38+1.12 [-0.75, 2.83]3.01 [1.16, 3.85]20% [0%, 56%]45%65%+0.01+0.062026-08-06 → 2026-08-30
tmin12Znearestall20 1 QC2.51 [0.96, 3.59]2.38+1.12 [-0.79, 2.58]3.01 [1.14, 3.85]20% [0%, 59%]45%65%+0.01+0.062026-08-06 → 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 5, 00Z bilinear tmax+20+100-10-202026-08-06: +1.69 °F2026-08-12: -7.04 °F2026-08-13: -4.58 °F2026-08-14: -6.14 °F2026-08-16: +3.48 °F2026-08-17: +3.64 °F2026-08-19: -2.19 °F2026-08-20: +2.34 °F2026-08-21: +1.73 °F2026-08-22: -0.55 °F2026-08-23: +1.83 °F2026-08-24: +1.12 °F2026-08-25: +0.64 °F2026-08-26: -3.77 °F2026-08-27: -13.26 °F2026-08-28: -8.51 °F2026-08-29: -2.91 °F2026-08-30: -1.95 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.95
2026-08-29-2.91
2026-08-28-8.51
2026-08-27-13.26
2026-08-26-3.77
2026-08-25+0.64
2026-08-24+1.12
2026-08-23+1.83
2026-08-22-0.55
2026-08-21+1.73
2026-08-20+2.34
2026-08-19-2.19
2026-08-18—
2026-08-17+3.64
2026-08-16+3.48
2026-08-15—
2026-08-14-6.14
2026-08-13-4.58
2026-08-12-7.04
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06+1.69

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KATL, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 1 day-8 to -6 °F: 2 days-6 to -4 °F: 1 day-4 to -2 °F: 3 days-2 to 0 °F: 2 days0 to 2 °F: 5 days2 to 4 °F: 3 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 2.63 · P90 |e| 7.48 °F-200+20 °Fn = 18 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.001
-12.00-10.000
-10.00-8.001
-8.00-6.002
-6.00-4.001
-4.00-2.003
-2.00+0.002
+0.00+2.005
+2.00+4.003
+4.00+6.000
+6.00+8.000
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08183.74 -1.91

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 20
ECMWF IFS HRES2026-08-06 → 2026-08-30 20

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 18 -1.03 [-2.50, -0.01] yes
NCEP GFS 18 -0.61 [-2.69, 2.69] no
GraphCast (IFS init) 18 -1.47 [-3.69, -0.63] yes
Persistence (baseline) 18 +0.91 [-0.90, 2.20] no

Cite this page

ShortCastCheck, KATL ifs_hres lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KATL/model/ifs_hres/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KATL (Atlanta Hartsfield), model ifs_hres, lead day 5. 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/5/

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