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

Oklahoma City · GraphCast (IFS init) · lead day 1

KOKC · graphcast_ifs · 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, GRAP_v100, starting 2026-01-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 2 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 2 QC6.97 [5.90, 7.96]2.03-6.97 [-7.96, -5.90]7.48 [6.43, 8.31]7% [0%, 14%]7%11%-1.00+0.422026-08-02 → 2026-08-30
tmax00Zbilinear90d27 2 QC6.97 [5.70, 8.10]2.03-6.97 [-8.10, -5.70]7.48 [6.27, 8.31]7% [0%, 14%]7%11%-1.00+0.422026-08-02 → 2026-08-30
tmax00Zbilinear365d33 2 QC7.16 [6.08, 8.21]2.15-7.16 [-8.21, -6.08]7.70 [6.67, 8.58]6% [0%, 12%]6%9%-0.63+0.512026-01-02 → 2026-08-30
tmax00Zbilinearall33 2 QC7.16 [6.07, 8.30]2.15-7.16 [-8.30, -6.07]7.70 [6.62, 8.67]6% [0%, 12%]6%9%-0.63+0.512026-01-02 → 2026-08-30
tmax00Znearest30d27 2 QC6.97 [5.82, 8.07]2.09-6.97 [-8.07, -5.82]7.51 [6.39, 8.45]7% [0%, 14%]7%11%-1.00+0.402026-08-02 → 2026-08-30
tmax00Znearest90d27 2 QC6.97 [5.66, 8.07]2.09-6.97 [-8.07, -5.66]7.51 [6.13, 8.41]7% [0%, 14%]7%11%-1.00+0.402026-08-02 → 2026-08-30
tmax00Znearest365d33 2 QC7.21 [6.12, 8.28]2.18-7.21 [-8.28, -6.12]7.76 [6.62, 8.66]6% [0%, 12%]6%9%-0.64+0.502026-01-02 → 2026-08-30
tmax00Znearestall33 2 QC7.21 [6.05, 8.35]2.18-7.21 [-8.35, -6.05]7.76 [6.62, 8.83]6% [0%, 12%]6%9%-0.64+0.502026-01-02 → 2026-08-30
tmax12Zbilinear30d27 2 QC8.31 [7.26, 9.39]2.23-8.31 [-9.39, -7.26]8.85 [7.68, 9.87]4% [0%, 11%]4%7%-1.39+0.362026-08-02 → 2026-08-30
tmax12Zbilinear90d27 2 QC8.31 [6.98, 9.45]2.23-8.31 [-9.45, -6.98]8.85 [7.39, 9.89]4% [0%, 11%]4%7%-1.39+0.362026-08-02 → 2026-08-30
tmax12Zbilinear365d32 2 QC8.37 [7.31, 9.41]2.28-8.37 [-9.41, -7.31]8.92 [7.79, 9.86]3% [0%, 10%]3%6%-0.90+0.492026-01-02 → 2026-08-30
tmax12Zbilinearall32 2 QC8.37 [7.32, 9.51]2.28-8.37 [-9.51, -7.32]8.92 [7.82, 9.95]3% [0%, 10%]3%6%-0.90+0.492026-01-02 → 2026-08-30
tmax12Znearest30d27 2 QC8.10 [6.91, 9.30]2.33-8.10 [-9.30, -6.91]8.70 [7.28, 9.98]0% [0%, 0%]4%11%-1.33+0.332026-08-02 → 2026-08-30
tmax12Znearest90d27 2 QC8.10 [6.69, 9.31]2.33-8.10 [-9.31, -6.69]8.70 [6.99, 10.02]0% [0%, 0%]4%11%-1.33+0.332026-08-02 → 2026-08-30
tmax12Znearest365d32 2 QC8.24 [7.13, 9.42]2.34-8.24 [-9.42, -7.13]8.82 [7.49, 10.00]0% [0%, 0%]3%9%-0.87+0.472026-01-02 → 2026-08-30
tmax12Znearestall32 2 QC8.24 [7.10, 9.39]2.34-8.24 [-9.39, -7.10]8.82 [7.52, 10.11]0% [0%, 0%]3%9%-0.87+0.472026-01-02 → 2026-08-30
tmin00Zbilinear30d27 2 QC4.31 [2.62, 6.42]2.38+4.19 [2.44, 6.36]5.25 [3.20, 7.15]11% [0%, 23%]30%33%-0.31+0.282026-08-02 → 2026-08-30
tmin00Zbilinear90d27 2 QC4.31 [2.64, 6.94]2.38+4.19 [2.46, 6.79]5.25 [3.24, 7.43]11% [0%, 24%]30%33%-0.31+0.282026-08-02 → 2026-08-30
tmin00Zbilinear365d33 2 QC4.42 [2.82, 6.30]2.41+4.33 [2.66, 6.25]5.34 [3.38, 6.98]9% [0%, 20%]27%36%-0.08+0.422026-01-02 → 2026-08-30
tmin00Zbilinearall33 2 QC4.42 [2.81, 6.55]2.41+4.33 [2.65, 6.54]5.34 [3.45, 7.20]9% [0%, 21%]27%36%-0.08+0.422026-01-02 → 2026-08-30
tmin00Znearest30d27 2 QC4.46 [2.73, 6.62]2.44+4.32 [2.48, 6.55]5.39 [3.28, 7.31]11% [0%, 23%]26%33%-0.35+0.262026-08-02 → 2026-08-30
tmin00Znearest90d27 2 QC4.46 [2.76, 7.10]2.44+4.32 [2.47, 7.00]5.39 [3.34, 7.61]11% [0%, 24%]26%33%-0.35+0.262026-08-02 → 2026-08-30
tmin00Znearest365d33 2 QC4.56 [2.92, 6.45]2.47+4.44 [2.67, 6.41]5.45 [3.47, 7.17]9% [0%, 20%]21%36%-0.11+0.402026-01-02 → 2026-08-30
tmin00Znearestall33 2 QC4.56 [2.91, 6.77]2.47+4.44 [2.66, 6.68]5.45 [3.53, 7.31]9% [0%, 21%]21%36%-0.11+0.402026-01-02 → 2026-08-30
tmin12Zbilinear30d27 2 QC3.55 [2.04, 5.46]2.58+3.03 [1.10, 5.30]4.45 [2.52, 6.14]22% [0%, 43%]30%52%-0.08+0.222026-08-02 → 2026-08-30
tmin12Zbilinear90d27 2 QC3.55 [2.01, 5.90]2.58+3.03 [1.03, 5.82]4.45 [2.51, 6.44]22% [0%, 44%]30%52%-0.08+0.222026-08-02 → 2026-08-30
tmin12Zbilinear365d32 2 QC3.46 [2.12, 5.16]2.42+3.02 [1.27, 5.05]4.30 [2.62, 5.88]19% [0%, 39%]31%53%+0.16+0.412026-01-02 → 2026-08-30
tmin12Zbilinearall32 2 QC3.46 [2.11, 5.34]2.42+3.02 [1.20, 5.26]4.30 [2.62, 6.01]19% [0%, 38%]31%53%+0.16+0.412026-01-02 → 2026-08-30
tmin12Znearest30d27 2 QC3.90 [2.21, 5.98]2.72+3.39 [1.22, 5.84]4.78 [2.75, 6.54]15% [0%, 37%]30%48%-0.18+0.182026-08-02 → 2026-08-30
tmin12Znearest90d27 2 QC3.90 [2.23, 6.40]2.72+3.39 [1.15, 6.34]4.78 [2.72, 6.89]15% [0%, 38%]30%48%-0.18+0.182026-08-02 → 2026-08-30
tmin12Znearest365d32 2 QC3.77 [2.28, 5.60]2.54+3.34 [1.40, 5.51]4.60 [2.77, 6.26]12% [0%, 33%]31%50%+0.08+0.392026-01-02 → 2026-08-30
tmin12Znearestall32 2 QC3.77 [2.25, 5.81]2.54+3.34 [1.28, 5.78]4.60 [2.75, 6.40]12% [0%, 33%]31%50%+0.08+0.392026-01-02 → 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 GraphCast (IFS init) at KOKC, lead day 1, 00Z bilinear tmax+20+100-10-202026-08-02: -4.37 °F2026-08-03: -5.12 °F2026-08-04: -7.21 °F2026-08-05: -6.24 °F2026-08-06: -3.87 °F2026-08-07: -0.97 °F2026-08-08: -7.04 °F2026-08-09: -9.85 °F2026-08-10: -8.09 °F2026-08-11: -6.95 °F2026-08-12: -8.27 °F2026-08-13: -9.08 °F2026-08-14: -8.48 °F2026-08-15: -6.57 °F2026-08-16: -7.13 °F2026-08-17: -7.94 °F2026-08-18: -10.08 °F2026-08-19: -5.23 °F2026-08-20: -10.93 °F2026-08-21: -2.64 °F2026-08-22: -0.31 °F2026-08-23: -6.91 °F2026-08-24: -8.61 °F2026-08-25: -12.22 °F2026-08-26: -7.77 °F2026-08-29: -8.29 °F2026-08-30: -7.91 °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
2026-08-30-7.91
2026-08-29-8.29
2026-08-28—
2026-08-27—
2026-08-26-7.77
2026-08-25-12.22
2026-08-24-8.61
2026-08-23-6.91
2026-08-22-0.31
2026-08-21-2.64
2026-08-20-10.93
2026-08-19-5.23
2026-08-18-10.08
2026-08-17-7.94
2026-08-16-7.13
2026-08-15-6.57
2026-08-14-8.48
2026-08-13-9.08
2026-08-12-8.27
2026-08-11-6.95
2026-08-10-8.09
2026-08-09-9.85
2026-08-08-7.04
2026-08-07-0.97
2026-08-06-3.87
2026-08-05-6.24
2026-08-04-7.21
2026-08-03-5.12
2026-08-02-4.37

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 1-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 2 days-12 to -10 °F: 3 days-10 to -8 °F: 8 days-8 to -6 °F: 11 days-6 to -4 °F: 5 days-4 to -2 °F: 2 days-2 to 0 °F: 2 days0 to 2 °F: 0 days2 to 4 °F: 0 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| 7.21 · P90 |e| 10.63 °F-200+20 °Fn = 33 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
-14.00-12.002
-12.00-10.003
-10.00-8.008
-8.00-6.0011
-6.00-4.005
-4.00-2.002
-2.00+0.002
+0.00+2.000
+2.00+4.000
+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
2026-08276.97 -6.97
2026-0168.02 -8.02

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 32
GraphCast (IFS init)2026-01-02 → 2026-08-30 32

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means GraphCast (IFS init) has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 27 +3.31 [2.18, 4.52] yes
Aurora (GFS init) 1 +0.39 [0.39, 0.39] yes
Aurora (IFS init) 2 +0.53 [0.36, 0.70] yes
FourCastNet v2 (GFS init) 1 +1.67 [1.67, 1.67] yes
FourCastNet v2 (IFS init) 2 +0.97 [0.74, 1.19] yes
NCEP GFS 27 +4.24 [2.06, 6.60] yes
GraphCast (GFS init) 1 +0.23 [0.23, 0.23] yes
ECMWF IFS HRES 21 +3.67 [2.61, 4.57] yes
Pangu-Weather (GFS init) 1 +5.25 [5.25, 5.25] yes
Pangu-Weather (IFS init) 2 +2.88 [2.20, 3.57] yes
Persistence (baseline) 27 +3.48 [1.96, 5.43] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model graphcast_ifs, 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/KOKC/model/graphcast_ifs/lead/1/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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