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

Oklahoma City · GraphCast (IFS init) · lead day 2

KOKC · graphcast_ifs · 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, 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, 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
tmax00Zbilinear30d26 1 QC7.67 [6.34, 8.62]1.69-7.67 [-8.62, -6.34]8.01 [6.83, 8.80]4% [0%, 11%]4%4%-0.68+0.632026-08-03 → 2026-08-30
tmax00Zbilinear90d26 1 QC7.67 [5.98, 8.59]1.69-7.67 [-8.59, -5.98]8.01 [6.46, 8.75]4% [0%, 12%]4%4%-0.68+0.632026-08-03 → 2026-08-30
tmax00Zbilinear365d32 1 QC7.69 [6.44, 8.59]2.12-7.69 [-8.59, -6.44]8.17 [7.03, 8.98]3% [0%, 9%]3%3%-0.32+0.642026-01-03 → 2026-08-30
tmax00Zbilinearall32 1 QC7.69 [6.40, 8.60]2.12-7.69 [-8.60, -6.40]8.17 [7.01, 9.03]3% [0%, 10%]3%3%-0.32+0.642026-01-03 → 2026-08-30
tmax00Znearest30d26 1 QC7.80 [6.35, 8.81]1.76-7.80 [-8.81, -6.35]8.15 [6.83, 9.03]4% [0%, 11%]4%4%-0.70+0.622026-08-03 → 2026-08-30
tmax00Znearest90d26 1 QC7.80 [5.91, 8.79]1.76-7.80 [-8.79, -5.91]8.15 [6.40, 9.02]4% [0%, 12%]4%4%-0.70+0.622026-08-03 → 2026-08-30
tmax00Znearest365d32 1 QC7.83 [6.50, 8.80]2.17-7.83 [-8.80, -6.50]8.31 [7.05, 9.18]3% [0%, 9%]3%3%-0.35+0.632026-01-03 → 2026-08-30
tmax00Znearestall32 1 QC7.83 [6.48, 8.81]2.17-7.83 [-8.81, -6.48]8.31 [7.10, 9.26]3% [0%, 10%]3%3%-0.35+0.632026-01-03 → 2026-08-30
tmax12Zbilinear30d26 1 QC8.73 [7.53, 9.91]2.03-8.73 [-9.91, -7.53]9.20 [7.94, 10.35]0% [0%, 0%]0%4%-0.91+0.562026-08-03 → 2026-08-30
tmax12Zbilinear90d26 1 QC8.73 [7.35, 9.83]2.03-8.73 [-9.83, -7.35]9.20 [7.73, 10.30]0% [0%, 0%]0%4%-0.91+0.562026-08-03 → 2026-08-30
tmax12Zbilinear365d31 1 QC8.80 [7.59, 9.93]2.28-8.80 [-9.93, -7.59]9.34 [8.04, 10.47]0% [0%, 0%]0%3%-0.48+0.622026-01-03 → 2026-08-30
tmax12Zbilinearall31 1 QC8.80 [7.66, 10.00]2.28-8.80 [-10.00, -7.66]9.34 [8.11, 10.56]0% [0%, 0%]0%3%-0.48+0.622026-01-03 → 2026-08-30
tmax12Znearest30d26 1 QC8.71 [7.36, 10.00]2.03-8.71 [-10.00, -7.36]9.20 [7.77, 10.53]0% [0%, 0%]4%4%-0.90+0.562026-08-03 → 2026-08-30
tmax12Znearest90d26 1 QC8.71 [7.03, 10.01]2.03-8.71 [-10.01, -7.03]9.20 [7.45, 10.55]0% [0%, 0%]4%4%-0.90+0.562026-08-03 → 2026-08-30
tmax12Znearest365d31 1 QC8.83 [7.47, 10.09]2.27-8.83 [-10.09, -7.47]9.37 [7.92, 10.65]0% [0%, 0%]3%3%-0.48+0.622026-01-03 → 2026-08-30
tmax12Znearestall31 1 QC8.83 [7.53, 10.20]2.27-8.83 [-10.20, -7.53]9.37 [8.01, 10.77]0% [0%, 0%]3%3%-0.48+0.622026-01-03 → 2026-08-30
tmin00Zbilinear30d26 1 QC4.28 [2.76, 6.24]2.85+3.71 [1.90, 6.05]5.21 [3.32, 7.07]8% [0%, 20%]27%35%-0.12+0.242026-08-03 → 2026-08-30
tmin00Zbilinear90d26 1 QC4.28 [2.73, 6.59]2.85+3.71 [1.88, 6.56]5.21 [3.27, 7.28]8% [0%, 20%]27%35%-0.12+0.242026-08-03 → 2026-08-30
tmin00Zbilinear365d32 1 QC4.88 [3.05, 7.00]3.22+4.42 [2.23, 6.83]6.03 [3.60, 8.10]6% [0%, 17%]22%34%-0.07+0.282026-01-03 → 2026-08-30
tmin00Zbilinearall32 1 QC4.88 [3.10, 7.27]3.22+4.42 [2.19, 7.13]6.03 [3.62, 8.22]6% [0%, 16%]22%34%-0.07+0.282026-01-03 → 2026-08-30
tmin00Znearest30d26 1 QC4.33 [2.80, 6.33]2.93+3.71 [1.80, 6.08]5.26 [3.33, 7.14]8% [0%, 20%]27%38%-0.14+0.222026-08-03 → 2026-08-30
tmin00Znearest90d26 1 QC4.33 [2.77, 6.72]2.93+3.71 [1.77, 6.67]5.26 [3.28, 7.41]8% [0%, 20%]27%38%-0.14+0.222026-08-03 → 2026-08-30
tmin00Znearest365d32 1 QC4.89 [3.08, 7.02]3.26+4.39 [2.14, 6.87]6.05 [3.58, 8.14]6% [0%, 17%]25%38%-0.07+0.272026-01-03 → 2026-08-30
tmin00Znearestall32 1 QC4.89 [3.10, 7.25]3.26+4.39 [2.12, 7.18]6.05 [3.62, 8.25]6% [0%, 16%]25%38%-0.07+0.272026-01-03 → 2026-08-30
tmin12Zbilinear30d26 1 QC3.58 [2.37, 5.27]2.68+2.85 [1.07, 4.98]4.48 [2.85, 6.14]19% [0%, 33%]38%46%+0.06+0.292026-08-03 → 2026-08-30
tmin12Zbilinear90d26 1 QC3.58 [2.38, 5.59]2.68+2.85 [1.11, 5.48]4.48 [2.84, 6.31]19% [0%, 33%]38%46%+0.06+0.292026-08-03 → 2026-08-30
tmin12Zbilinear365d31 1 QC3.89 [2.53, 5.54]2.76+3.28 [1.40, 5.47]4.81 [3.02, 6.33]16% [0%, 30%]35%45%+0.15+0.392026-01-03 → 2026-08-30
tmin12Zbilinearall31 1 QC3.89 [2.60, 5.73]2.76+3.28 [1.39, 5.60]4.81 [3.04, 6.47]16% [0%, 30%]35%45%+0.15+0.392026-01-03 → 2026-08-30
tmin12Znearest30d26 1 QC3.72 [2.46, 5.51]2.73+2.99 [1.09, 5.19]4.61 [2.92, 6.35]15% [0%, 29%]31%46%+0.02+0.272026-08-03 → 2026-08-30
tmin12Znearest90d26 1 QC3.72 [2.46, 5.82]2.73+2.99 [1.05, 5.75]4.61 [2.92, 6.57]15% [0%, 29%]31%46%+0.02+0.272026-08-03 → 2026-08-30
tmin12Znearest365d31 1 QC3.98 [2.59, 5.71]2.80+3.36 [1.42, 5.53]4.89 [3.06, 6.46]13% [0%, 25%]32%45%+0.13+0.382026-01-03 → 2026-08-30
tmin12Znearestall31 1 QC3.98 [2.65, 5.90]2.80+3.36 [1.44, 5.69]4.89 [3.11, 6.62]13% [0%, 24%]32%45%+0.13+0.382026-01-03 → 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 GraphCast (IFS init) at KOKC, lead day 2, 00Z bilinear tmax+20+100-10-202026-08-03: -5.33 °F2026-08-04: -7.67 °F2026-08-05: -6.93 °F2026-08-06: -4 °F2026-08-07: -0.65 °F2026-08-08: -7.35 °F2026-08-09: -6.07 °F2026-08-10: -9.21 °F2026-08-11: -7.76 °F2026-08-12: -7.76 °F2026-08-13: -10 °F2026-08-14: -9.31 °F2026-08-15: -6.99 °F2026-08-16: -8.11 °F2026-08-17: -9.66 °F2026-08-18: -10.63 °F2026-08-19: -5.88 °F2026-08-20: -10.02 °F2026-08-21: -9.06 °F2026-08-22: -6.03 °F2026-08-23: -5.52 °F2026-08-24: -8.2 °F2026-08-25: -12.71 °F2026-08-26: -8.07 °F2026-08-27: -7.96 °F2026-08-30: -8.47 °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
2026-08-30-8.47
2026-08-29—
2026-08-28—
2026-08-27-7.96
2026-08-26-8.07
2026-08-25-12.71
2026-08-24-8.20
2026-08-23-5.52
2026-08-22-6.03
2026-08-21-9.06
2026-08-20-10.02
2026-08-19-5.88
2026-08-18-10.63
2026-08-17-9.66
2026-08-16-8.11
2026-08-15-6.99
2026-08-14-9.31
2026-08-13-10.00
2026-08-12-7.76
2026-08-11-7.76
2026-08-10-9.21
2026-08-09-6.07
2026-08-08-7.35
2026-08-07-0.65
2026-08-06-4.00
2026-08-05-6.93
2026-08-04-7.67
2026-08-03-5.33

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 2-20 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: 4 days-10 to -8 °F: 9 days-8 to -6 °F: 9 days-6 to -4 °F: 3 days-4 to -2 °F: 4 days-2 to 0 °F: 1 day0 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| 7.86 · P90 |e| 10.57 °F-200+20 °Fn = 32 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
-12.00-10.004
-10.00-8.009
-8.00-6.009
-6.00-4.003
-4.00-2.004
-2.00+0.001
+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
2026-08267.67 -7.67
2026-0167.78 -7.78

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 31
GraphCast (IFS init)2026-01-03 → 2026-08-30 31

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 26 +4.07 [2.58, 4.99] yes
Aurora (IFS init) 1 +1.21 [1.21, 1.21] yes
FourCastNet v2 (IFS init) 1 +1.45 [1.45, 1.45] yes
NCEP GFS 26 +4.43 [1.84, 6.68] yes
ECMWF IFS HRES 20 +5.35 [4.02, 5.99] yes
Pangu-Weather (IFS init) 1 +3.51 [3.51, 3.51] yes
Persistence (baseline) 26 +3.09 [0.65, 5.15] yes

Cite this page

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

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