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

Oklahoma City · GraphCast (IFS init) · lead day 9

KOKC · graphcast_ifs · lead 9

Target day = initialization date + 9 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, 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
tmax00Zbilinear30d21 2 QC10.37 [8.09, 12.73]4.77-10.35 [-12.73, -8.01]11.92 [9.86, 14.03]10% [0%, 27%]10%14%-1.07+0.032026-08-10 → 2026-08-30
tmax00Zbilinear90d21 2 QC10.37 [7.84, 12.97]4.77-10.35 [-12.95, -7.80]11.92 [9.47, 14.48]10% [0%, 29%]10%14%-1.07+0.032026-08-10 → 2026-08-30
tmax00Zbilinear365d27 2 QC10.09 [7.94, 12.25]6.39-8.39 [-11.88, -3.48]11.70 [9.58, 13.65]11% [0%, 27%]15%19%-0.37+0.152026-01-10 → 2026-08-30
tmax00Zbilinearall27 2 QC10.09 [7.94, 12.21]6.39-8.39 [-11.74, -3.50]11.70 [9.75, 13.62]11% [0%, 26%]15%19%-0.37+0.152026-01-10 → 2026-08-30
tmax00Znearest30d21 2 QC10.60 [8.29, 13.04]4.87-10.52 [-13.04, -8.09]12.16 [9.95, 14.35]10% [0%, 27%]10%14%-1.12+0.012026-08-10 → 2026-08-30
tmax00Znearest90d21 2 QC10.60 [7.74, 13.34]4.87-10.52 [-13.29, -7.74]12.16 [9.43, 14.81]10% [0%, 29%]10%14%-1.12+0.012026-08-10 → 2026-08-30
tmax00Znearest365d27 2 QC10.27 [8.05, 12.53]6.47-8.56 [-12.18, -3.60]11.90 [9.58, 13.92]11% [0%, 27%]15%19%-0.39+0.142026-01-10 → 2026-08-30
tmax00Znearestall27 2 QC10.27 [8.06, 12.48]6.47-8.56 [-12.05, -3.61]11.90 [9.79, 13.92]11% [0%, 26%]15%19%-0.39+0.142026-01-10 → 2026-08-30
tmax12Zbilinear30d21 2 QC11.69 [9.16, 14.55]4.28-11.67 [-14.55, -9.10]12.82 [10.75, 15.01]5% [0%, 14%]5%5%-1.34+0.132026-08-10 → 2026-08-30
tmax12Zbilinear90d21 2 QC11.69 [9.12, 15.31]4.28-11.67 [-15.31, -9.07]12.82 [10.58, 15.60]5% [0%, 14%]5%5%-1.34+0.132026-08-10 → 2026-08-30
tmax12Zbilinear365d26 2 QC11.66 [9.32, 14.48]5.22-10.92 [-13.96, -7.63]12.89 [10.75, 15.22]4% [0%, 12%]4%4%-0.64+0.272026-01-10 → 2026-08-30
tmax12Zbilinearall26 2 QC11.66 [9.16, 14.11]5.22-10.92 [-13.71, -7.77]12.89 [10.78, 14.83]4% [0%, 12%]4%4%-0.64+0.272026-01-10 → 2026-08-30
tmax12Znearest30d21 2 QC11.92 [9.28, 14.97]4.44-11.89 [-14.97, -9.18]13.10 [10.86, 15.46]5% [0%, 14%]5%5%-1.38+0.092026-08-10 → 2026-08-30
tmax12Znearest90d21 2 QC11.92 [9.23, 15.78]4.44-11.89 [-15.78, -9.15]13.10 [10.71, 16.09]5% [0%, 14%]5%5%-1.38+0.092026-08-10 → 2026-08-30
tmax12Znearest365d26 2 QC11.89 [9.33, 14.88]5.34-11.18 [-14.39, -7.82]13.15 [10.82, 15.60]4% [0%, 12%]4%4%-0.67+0.262026-01-10 → 2026-08-30
tmax12Znearestall26 2 QC11.89 [9.31, 14.47]5.34-11.18 [-14.13, -8.05]13.15 [10.85, 15.17]4% [0%, 12%]4%4%-0.67+0.262026-01-10 → 2026-08-30
tmin00Zbilinear30d21 2 QC3.03 [2.04, 4.08]2.97+1.02 [0.15, 1.99]3.69 [2.60, 4.66]24% [11%, 42%]33%57%+0.44+0.382026-08-10 → 2026-08-30
tmin00Zbilinear90d21 2 QC3.03 [2.01, 4.18]2.97+1.02 [0.12, 2.17]3.69 [2.48, 4.72]24% [10%, 40%]33%57%+0.44+0.382026-08-10 → 2026-08-30
tmin00Zbilinear365d27 2 QC4.37 [2.42, 7.72]4.25+2.80 [0.56, 6.93]6.74 [2.99, 11.01]26% [12%, 38%]37%56%+0.29+0.312026-01-10 → 2026-08-30
tmin00Zbilinearall27 2 QC4.37 [2.50, 8.21]4.25+2.80 [0.62, 7.53]6.74 [3.13, 11.76]26% [13%, 40%]37%56%+0.29+0.312026-01-10 → 2026-08-30
tmin00Znearest30d21 2 QC3.10 [2.13, 4.20]3.04+0.94 [0.01, 1.93]3.76 [2.63, 4.78]24% [11%, 42%]38%57%+0.43+0.362026-08-10 → 2026-08-30
tmin00Znearest90d21 2 QC3.10 [2.09, 4.25]3.04+0.94 [-0.03, 2.12]3.76 [2.53, 4.89]24% [10%, 40%]38%57%+0.43+0.362026-08-10 → 2026-08-30
tmin00Znearest365d27 2 QC4.37 [2.47, 7.59]4.30+2.69 [0.47, 6.79]6.67 [3.02, 10.81]26% [12%, 38%]41%56%+0.29+0.302026-01-10 → 2026-08-30
tmin00Znearestall27 2 QC4.37 [2.54, 8.07]4.30+2.69 [0.50, 7.30]6.67 [3.21, 11.54]26% [13%, 40%]41%56%+0.29+0.302026-01-10 → 2026-08-30
tmin12Zbilinear30d21 2 QC2.32 [1.71, 2.95]2.31+0.17 [-0.93, 0.95]2.95 [1.94, 3.73]19% [5%, 32%]62%67%+0.57+0.512026-08-10 → 2026-08-30
tmin12Zbilinear90d21 2 QC2.32 [1.66, 2.98]2.31+0.17 [-1.15, 0.97]2.95 [1.78, 3.73]19% [0%, 32%]62%67%+0.57+0.512026-08-10 → 2026-08-30
tmin12Zbilinear365d26 2 QC3.01 [1.94, 4.85]2.91+0.90 [-0.54, 2.93]4.26 [2.27, 6.73]15% [0%, 29%]50%62%+0.47+0.472026-01-10 → 2026-08-30
tmin12Zbilinearall26 2 QC3.01 [1.90, 5.19]2.91+0.90 [-0.51, 3.30]4.26 [2.20, 7.02]15% [0%, 28%]50%62%+0.47+0.472026-01-10 → 2026-08-30
tmin12Znearest30d21 2 QC2.36 [1.71, 3.04]2.37+0.07 [-1.14, 0.90]3.02 [1.99, 3.79]24% [14%, 33%]57%67%+0.56+0.502026-08-10 → 2026-08-30
tmin12Znearest90d21 2 QC2.36 [1.66, 3.11]2.37+0.07 [-1.32, 0.96]3.02 [1.84, 3.85]24% [12%, 33%]57%67%+0.56+0.502026-08-10 → 2026-08-30
tmin12Znearest365d26 2 QC3.02 [1.96, 4.78]2.96+0.78 [-0.71, 2.75]4.25 [2.31, 6.63]19% [5%, 30%]46%62%+0.47+0.462026-01-10 → 2026-08-30
tmin12Znearestall26 2 QC3.02 [1.91, 5.09]2.96+0.78 [-0.67, 3.19]4.25 [2.28, 6.91]19% [0%, 30%]46%62%+0.47+0.462026-01-10 → 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 9, 00Z bilinear tmax+25+12.50-12.5-252026-08-10: -7.84 °F2026-08-11: -10.99 °F2026-08-12: -9.7 °F2026-08-13: -15.65 °F2026-08-14: -17.81 °F2026-08-15: -8.95 °F2026-08-16: -13.39 °F2026-08-17: -4.83 °F2026-08-18: -18.07 °F2026-08-19: -8.83 °F2026-08-20: -13.79 °F2026-08-21: -6.75 °F2026-08-22: -2.25 °F2026-08-23: -8.57 °F2026-08-24: -14.28 °F2026-08-25: -10.74 °F2026-08-26: +0.2 °F2026-08-27: +0.1 °F2026-08-28: -6.34 °F2026-08-29: -23.48 °F2026-08-30: -15.32 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-15.32
2026-08-29-23.48
2026-08-28-6.34
2026-08-27+0.10
2026-08-26+0.20
2026-08-25-10.74
2026-08-24-14.28
2026-08-23-8.57
2026-08-22-2.25
2026-08-21-6.75
2026-08-20-13.79
2026-08-19-8.83
2026-08-18-18.07
2026-08-17-4.83
2026-08-16-13.39
2026-08-15-8.95
2026-08-14-17.81
2026-08-13-15.65
2026-08-12-9.70
2026-08-11-10.99
2026-08-10-7.84

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 9-25 to -22.5 °F: 1 day-22.5 to -20 °F: 0 days-20 to -17.5 °F: 2 days-17.5 to -15 °F: 3 days-15 to -12.5 °F: 4 days-12.5 to -10 °F: 2 days-10 to -7.5 °F: 5 days-7.5 to -5 °F: 2 days-5 to -2.5 °F: 1 day-2.5 to 0 °F: 2 days0 to 2.5 °F: 3 days2.5 to 5 °F: 0 days5 to 7.5 °F: 0 days7.5 to 10 °F: 0 days10 to 12.5 °F: 2 days12.5 to 15 °F: 0 days15 to 17.5 °F: 0 days17.5 to 20 °F: 0 days20 to 22.5 °F: 0 days22.5 to 25 °F: 0 daysdashed: P50 |e| 10.01 · P90 |e| 17.42 °F-250+25 °Fn = 27 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
-25.00-22.501
-22.50-20.000
-20.00-17.502
-17.50-15.003
-15.00-12.504
-12.50-10.002
-10.00-7.505
-7.50-5.002
-5.00-2.501
-2.50+0.002
+0.00+2.503
+2.50+5.000
+5.00+7.500
+7.50+10.000
+10.00+12.502
+12.50+15.000
+15.00+17.500
+17.50+20.000
+20.00+22.500
+22.50+25.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-082110.37 -10.35
2026-0169.10 -1.54

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-10 → 2026-08-30 27
GraphCast (IFS init)2026-01-10 → 2026-08-30 27
GraphCast (IFS init)2026-01-10 → 2026-08-30 26
GraphCast (IFS init)2026-01-10 → 2026-08-30 26

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 21 +3.21 [0.75, 6.41] yes
NCEP GFS 21 +7.23 [4.86, 9.86] yes
ECMWF IFS HRES 16 +5.61 [3.41, 9.85] yes
Persistence (baseline) 21 +5.37 [1.59, 8.79] yes

Cite this page

ShortCastCheck, KOKC graphcast_ifs lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KOKC/model/graphcast_ifs/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model graphcast_ifs, lead day 9. 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/9/

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