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

Oklahoma City · GraphCast (IFS init) · lead day 5

KOKC · graphcast_ifs · 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, 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
tmax00Zbilinear30d25 2 QC8.99 [8.13, 10.23]2.65-8.99 [-10.23, -8.13]9.50 [8.57, 10.67]0% [0%, 0%]0%0%-1.81+0.182026-08-06 → 2026-08-30
tmax00Zbilinear90d25 2 QC8.99 [8.03, 10.52]2.65-8.99 [-10.52, -8.03]9.50 [8.48, 10.94]0% [0%, 0%]0%0%-1.81+0.182026-08-06 → 2026-08-30
tmax00Zbilinear365d31 2 QC8.59 [7.20, 10.10]3.18-8.37 [-9.99, -6.61]9.29 [8.12, 10.59]3% [0%, 12%]3%3%-0.62+0.402026-01-06 → 2026-08-30
tmax00Zbilinearall31 2 QC8.59 [6.99, 9.95]3.18-8.37 [-9.77, -6.43]9.29 [8.11, 10.53]3% [0%, 14%]3%3%-0.62+0.402026-01-06 → 2026-08-30
tmax00Znearest30d25 2 QC9.21 [8.27, 10.51]2.75-9.21 [-10.51, -8.27]9.74 [8.73, 10.98]0% [0%, 0%]0%0%-1.88+0.152026-08-06 → 2026-08-30
tmax00Znearest90d25 2 QC9.21 [8.09, 10.95]2.75-9.21 [-10.95, -8.09]9.74 [8.60, 11.30]0% [0%, 0%]0%0%-1.88+0.152026-08-06 → 2026-08-30
tmax00Znearest365d31 2 QC8.80 [7.36, 10.40]3.23-8.57 [-10.27, -6.79]9.50 [8.33, 10.92]3% [0%, 12%]3%3%-0.66+0.392026-01-06 → 2026-08-30
tmax00Znearestall31 2 QC8.80 [7.17, 10.16]3.23-8.57 [-10.10, -6.57]9.50 [8.25, 10.76]3% [0%, 14%]3%3%-0.66+0.392026-01-06 → 2026-08-30
tmax12Zbilinear30d25 2 QC9.64 [8.70, 11.01]2.42-9.64 [-11.01, -8.70]10.02 [9.03, 11.34]0% [0%, 0%]0%0%-2.01+0.252026-08-06 → 2026-08-30
tmax12Zbilinear90d25 2 QC9.64 [8.56, 11.44]2.42-9.64 [-11.44, -8.56]10.02 [8.90, 11.78]0% [0%, 0%]0%0%-2.01+0.252026-08-06 → 2026-08-30
tmax12Zbilinear365d30 2 QC9.23 [7.88, 10.67]2.52-9.23 [-10.67, -7.88]9.71 [8.47, 11.09]0% [0%, 0%]0%0%-0.92+0.482026-01-06 → 2026-08-30
tmax12Zbilinearall30 2 QC9.23 [7.81, 10.63]2.52-9.23 [-10.63, -7.81]9.71 [8.42, 11.09]0% [0%, 0%]0%0%-0.92+0.482026-01-06 → 2026-08-30
tmax12Znearest30d25 2 QC9.82 [8.75, 11.28]2.50-9.82 [-11.28, -8.75]10.23 [9.11, 11.60]0% [0%, 0%]0%0%-2.07+0.232026-08-06 → 2026-08-30
tmax12Znearest90d25 2 QC9.82 [8.59, 11.74]2.50-9.82 [-11.74, -8.59]10.23 [8.97, 12.06]0% [0%, 0%]0%0%-2.07+0.232026-08-06 → 2026-08-30
tmax12Znearest365d30 2 QC9.40 [7.98, 10.98]2.62-9.40 [-10.98, -7.98]9.91 [8.58, 11.33]0% [0%, 0%]0%0%-0.96+0.462026-01-06 → 2026-08-30
tmax12Znearestall30 2 QC9.40 [7.91, 10.96]2.62-9.40 [-10.96, -7.91]9.91 [8.47, 11.39]0% [0%, 0%]0%0%-0.96+0.462026-01-06 → 2026-08-30
tmin00Zbilinear30d25 2 QC3.23 [1.86, 4.99]2.91+2.33 [0.32, 4.59]4.23 [2.53, 5.80]24% [6%, 44%]40%56%+0.04+0.122026-08-06 → 2026-08-30
tmin00Zbilinear90d25 2 QC3.23 [1.72, 5.49]2.91+2.33 [0.01, 5.30]4.23 [2.34, 6.13]24% [4%, 47%]40%56%+0.04+0.122026-08-06 → 2026-08-30
tmin00Zbilinear365d31 2 QC4.05 [1.97, 6.47]3.44+3.32 [0.77, 6.26]5.34 [2.75, 7.52]19% [0%, 39%]35%52%+0.08+0.222026-01-06 → 2026-08-30
tmin00Zbilinearall31 2 QC4.05 [2.18, 6.60]3.44+3.32 [0.91, 6.33]5.34 [2.98, 7.71]19% [0%, 38%]35%52%+0.08+0.222026-01-06 → 2026-08-30
tmin00Znearest30d25 2 QC3.22 [1.84, 4.95]2.92+2.28 [0.25, 4.53]4.21 [2.52, 5.75]32% [8%, 58%]40%56%+0.04+0.122026-08-06 → 2026-08-30
tmin00Znearest90d25 2 QC3.22 [1.72, 5.43]2.92+2.28 [-0.08, 5.23]4.21 [2.39, 6.09]32% [5%, 61%]40%56%+0.04+0.122026-08-06 → 2026-08-30
tmin00Znearest365d31 2 QC4.04 [1.97, 6.42]3.43+3.28 [0.68, 6.20]5.31 [2.73, 7.46]26% [0%, 53%]35%52%+0.09+0.222026-01-06 → 2026-08-30
tmin00Znearestall31 2 QC4.04 [2.19, 6.53]3.43+3.28 [0.82, 6.29]5.31 [2.99, 7.64]26% [0%, 51%]35%52%+0.09+0.222026-01-06 → 2026-08-30
tmin12Zbilinear30d25 2 QC3.23 [2.04, 4.98]3.07+1.69 [-0.59, 4.27]4.06 [2.47, 5.79]20% [8%, 35%]44%44%+0.04+0.082026-08-06 → 2026-08-30
tmin12Zbilinear90d25 2 QC3.23 [1.92, 5.46]3.07+1.69 [-0.93, 5.19]4.06 [2.38, 6.14]20% [5%, 39%]44%44%+0.04+0.082026-08-06 → 2026-08-30
tmin12Zbilinear365d30 2 QC3.77 [2.14, 5.82]3.38+2.49 [-0.23, 5.60]4.72 [2.62, 6.57]17% [4%, 33%]40%40%+0.11+0.192026-01-06 → 2026-08-30
tmin12Zbilinearall30 2 QC3.77 [2.23, 6.03]3.38+2.49 [-0.07, 5.71]4.72 [2.74, 6.70]17% [3%, 33%]40%40%+0.11+0.192026-01-06 → 2026-08-30
tmin12Znearest30d25 2 QC3.23 [2.05, 4.95]3.05+1.65 [-0.68, 4.25]4.04 [2.47, 5.75]16% [4%, 33%]44%44%+0.04+0.082026-08-06 → 2026-08-30
tmin12Znearest90d25 2 QC3.23 [1.94, 5.40]3.05+1.65 [-1.03, 5.15]4.04 [2.35, 6.09]16% [0%, 36%]44%44%+0.04+0.082026-08-06 → 2026-08-30
tmin12Znearest365d30 2 QC3.74 [2.13, 5.71]3.33+2.42 [-0.29, 5.50]4.66 [2.61, 6.46]13% [0%, 29%]40%40%+0.12+0.202026-01-06 → 2026-08-30
tmin12Znearestall30 2 QC3.74 [2.24, 5.84]3.33+2.42 [-0.16, 5.60]4.66 [2.73, 6.58]13% [0%, 31%]40%40%+0.12+0.202026-01-06 → 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 GraphCast (IFS init) at KOKC, lead day 5, 00Z bilinear tmax+20+100-10-202026-08-06: -5.41 °F2026-08-07: -14.28 °F2026-08-08: -11.33 °F2026-08-09: -5.15 °F2026-08-10: -6.51 °F2026-08-11: -6.27 °F2026-08-12: -5.49 °F2026-08-13: -9.21 °F2026-08-14: -12.44 °F2026-08-15: -7.71 °F2026-08-16: -8.52 °F2026-08-17: -5.31 °F2026-08-18: -14.11 °F2026-08-19: -6.86 °F2026-08-20: -13.53 °F2026-08-21: -6.26 °F2026-08-22: -5.84 °F2026-08-23: -7.6 °F2026-08-24: -9.61 °F2026-08-25: -9.04 °F2026-08-26: -7.53 °F2026-08-27: -8.26 °F2026-08-28: -13.62 °F2026-08-29: -13.53 °F2026-08-30: -11.3 °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
2026-08-30-11.30
2026-08-29-13.53
2026-08-28-13.62
2026-08-27-8.26
2026-08-26-7.53
2026-08-25-9.04
2026-08-24-9.61
2026-08-23-7.60
2026-08-22-5.84
2026-08-21-6.26
2026-08-20-13.53
2026-08-19-6.86
2026-08-18-14.11
2026-08-17-5.31
2026-08-16-8.52
2026-08-15-7.71
2026-08-14-12.44
2026-08-13-9.21
2026-08-12-5.49
2026-08-11-6.27
2026-08-10-6.51
2026-08-09-5.15
2026-08-08-11.33
2026-08-07-14.28
2026-08-06-5.41

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 2 days-14 to -12 °F: 6 days-12 to -10 °F: 2 days-10 to -8 °F: 5 days-8 to -6 °F: 8 days-6 to -4 °F: 6 days-4 to -2 °F: 0 days-2 to 0 °F: 1 day0 to 2 °F: 0 days2 to 4 °F: 1 day4 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| 7.71 · P90 |e| 13.53 °F-200+20 °Fn = 31 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
-16.00-14.002
-14.00-12.006
-12.00-10.002
-10.00-8.005
-8.00-6.008
-6.00-4.006
-4.00-2.000
-2.00+0.001
+0.00+2.000
+2.00+4.001
+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
2026-08258.99 -8.99
2026-0166.92 -5.77

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 30
GraphCast (IFS init)2026-01-06 → 2026-08-30 30

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 25 +4.45 [2.44, 6.13] yes
NCEP GFS 25 +5.08 [3.21, 7.25] yes
ECMWF IFS HRES 18 +5.82 [3.86, 7.77] yes
Persistence (baseline) 25 +5.79 [4.49, 7.45] yes

Cite this page

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

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