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

Oklahoma City · GraphCast (IFS init) · lead day 0

KOKC · graphcast_ifs · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d28 2 QC6.38 [5.29, 7.33]1.98-6.38 [-7.33, -5.29]6.86 [5.78, 7.67]4% [0%, 10%]7%7%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d28 2 QC6.38 [5.12, 7.35]1.98-6.38 [-7.35, -5.12]6.86 [5.62, 7.66]4% [0%, 11%]7%7%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d34 2 QC6.48 [5.49, 7.36]1.97-6.48 [-7.36, -5.49]6.97 [5.94, 7.72]3% [0%, 8%]6%6%——2026-01-01 → 2026-08-30
tmax00Zbilinearall34 2 QC6.48 [5.42, 7.40]1.97-6.48 [-7.40, -5.42]6.97 [5.86, 7.80]3% [0%, 9%]6%6%——2026-01-01 → 2026-08-30
tmax00Znearest30d28 2 QC6.14 [5.01, 7.14]2.13-6.14 [-7.14, -5.01]6.66 [5.49, 7.55]4% [0%, 10%]7%7%——2026-08-01 → 2026-08-30
tmax00Znearest90d28 2 QC6.14 [4.85, 7.19]2.13-6.14 [-7.19, -4.85]6.66 [5.32, 7.58]4% [0%, 11%]7%7%——2026-08-01 → 2026-08-30
tmax00Znearest365d34 2 QC6.30 [5.30, 7.25]2.08-6.30 [-7.25, -5.30]6.81 [5.79, 7.64]3% [0%, 8%]6%6%——2026-01-01 → 2026-08-30
tmax00Znearestall34 2 QC6.30 [5.23, 7.28]2.08-6.30 [-7.28, -5.23]6.81 [5.63, 7.74]3% [0%, 9%]6%6%——2026-01-01 → 2026-08-30
tmin00Zbilinear30d28 2 QC4.74 [3.22, 6.54]2.34+4.67 [3.15, 6.48]5.47 [3.75, 7.02]7% [0%, 15%]18%32%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d28 2 QC4.74 [3.14, 6.92]2.34+4.67 [3.05, 6.86]5.47 [3.68, 7.36]7% [0%, 15%]18%32%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d34 2 QC4.84 [3.42, 6.40]2.19+4.78 [3.35, 6.39]5.49 [3.98, 6.86]6% [0%, 14%]15%29%——2026-01-01 → 2026-08-30
tmin00Zbilinearall34 2 QC4.84 [3.41, 6.56]2.19+4.78 [3.30, 6.51]5.49 [3.96, 7.01]6% [0%, 14%]15%29%——2026-01-01 → 2026-08-30
tmin00Znearest30d28 2 QC5.16 [3.61, 6.94]2.43+5.05 [3.49, 6.87]5.85 [4.15, 7.41]7% [0%, 15%]11%25%——2026-08-01 → 2026-08-30
tmin00Znearest90d28 2 QC5.16 [3.55, 7.29]2.43+5.05 [3.39, 7.26]5.85 [4.09, 7.71]7% [0%, 15%]11%25%——2026-08-01 → 2026-08-30
tmin00Znearest365d34 2 QC5.26 [3.86, 6.82]2.26+5.17 [3.70, 6.78]5.88 [4.37, 7.27]6% [0%, 14%]9%24%——2026-01-01 → 2026-08-30
tmin00Znearestall34 2 QC5.26 [3.79, 6.96]2.26+5.17 [3.67, 6.89]5.88 [4.35, 7.38]6% [0%, 14%]9%24%——2026-01-01 → 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 0, 00Z bilinear tmax+20+100-10-202026-08-01: -4.36 °F2026-08-02: -4.12 °F2026-08-03: -4.31 °F2026-08-04: -5.54 °F2026-08-05: -4.84 °F2026-08-06: -4.31 °F2026-08-07: -0.55 °F2026-08-08: -11.26 °F2026-08-09: -5.92 °F2026-08-10: -6.35 °F2026-08-11: -7.16 °F2026-08-12: -7.13 °F2026-08-13: -8.07 °F2026-08-14: -8.1 °F2026-08-15: -5.44 °F2026-08-16: -7.14 °F2026-08-17: -7.51 °F2026-08-18: -9.45 °F2026-08-19: -5.38 °F2026-08-20: -8.79 °F2026-08-21: -3.48 °F2026-08-22: -1.06 °F2026-08-23: -8.27 °F2026-08-24: -7.92 °F2026-08-25: -11.58 °F2026-08-28: -8.25 °F2026-08-29: -6.34 °F2026-08-30: -6.02 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-6.02
2026-08-29-6.34
2026-08-28-8.25
2026-08-27—
2026-08-26—
2026-08-25-11.58
2026-08-24-7.92
2026-08-23-8.27
2026-08-22-1.06
2026-08-21-3.48
2026-08-20-8.79
2026-08-19-5.38
2026-08-18-9.45
2026-08-17-7.51
2026-08-16-7.14
2026-08-15-5.44
2026-08-14-8.10
2026-08-13-8.07
2026-08-12-7.13
2026-08-11-7.16
2026-08-10-6.35
2026-08-09-5.92
2026-08-08-11.26
2026-08-07-0.55
2026-08-06-4.31
2026-08-05-4.84
2026-08-04-5.54
2026-08-03-4.31
2026-08-02-4.12
2026-08-01-4.36

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 0-20 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: 2 days-10 to -8 °F: 6 days-8 to -6 °F: 10 days-6 to -4 °F: 12 days-4 to -2 °F: 1 day-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| 6.27 · P90 |e| 9.25 °F-200+20 °Fn = 34 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
-12.00-10.002
-10.00-8.006
-8.00-6.0010
-6.00-4.0012
-4.00-2.001
-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
2026-08286.38 -6.38
2026-0166.97 -6.97

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-01 → 2026-08-30 34
GraphCast (IFS init)2026-01-01 → 2026-08-30 34

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 28 +2.79 [1.94, 3.58] yes
Aurora (GFS init) 2 +1.02 [0.80, 1.25] yes
Aurora (IFS init) 3 +0.34 [-0.12, 0.88] no
FourCastNet v2 (GFS init) 2 +0.29 [0.10, 0.48] yes
FourCastNet v2 (IFS init) 3 +0.25 [-0.58, 1.90] no
NCEP GFS 28 +3.89 [2.16, 5.90] yes
GraphCast (GFS init) 2 +0.44 [0.27, 0.61] yes
ECMWF IFS HRES 22 +3.07 [2.37, 3.58] yes
Pangu-Weather (GFS init) 2 +2.62 [2.55, 2.70] yes
Pangu-Weather (IFS init) 3 +1.95 [1.79, 2.28] yes

Cite this page

ShortCastCheck, KOKC graphcast_ifs lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KOKC/model/graphcast_ifs/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model graphcast_ifs, lead day 0. 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/0/

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

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