Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

Oklahoma City · GraphCast (IFS init) · lead day 7

KOKC · graphcast_ifs · lead 7

Target day = initialization date + 7 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
tmax00Zbilinear30d23 2 QC10.31 [9.20, 11.61]3.42-10.31 [-11.61, -9.20]11.10 [9.80, 12.44]0% [0%, 0%]0%0%-1.16+0.292026-08-08 → 2026-08-30
tmax00Zbilinear90d23 2 QC10.31 [9.02, 11.78]3.42-10.31 [-11.78, -9.02]11.10 [9.58, 12.48]0% [0%, 0%]0%0%-1.16+0.292026-08-08 → 2026-08-30
tmax00Zbilinear365d29 2 QC9.97 [8.75, 11.38]3.17-9.97 [-11.38, -8.75]10.71 [9.22, 12.13]0% [0%, 0%]0%0%-1.05+0.352026-01-08 → 2026-08-30
tmax00Zbilinearall29 2 QC9.97 [8.73, 11.20]3.17-9.97 [-11.20, -8.73]10.71 [9.23, 11.97]0% [0%, 0%]0%0%-1.05+0.352026-01-08 → 2026-08-30
tmax00Znearest30d23 2 QC10.50 [9.32, 11.83]3.47-10.50 [-11.83, -9.32]11.30 [9.86, 12.71]0% [0%, 0%]0%0%-1.20+0.282026-08-08 → 2026-08-30
tmax00Znearest90d23 2 QC10.50 [9.13, 12.04]3.47-10.50 [-12.04, -9.13]11.30 [9.67, 12.78]0% [0%, 0%]0%0%-1.20+0.282026-08-08 → 2026-08-30
tmax00Znearest365d29 2 QC10.19 [9.00, 11.60]3.20-10.19 [-11.60, -9.00]10.93 [9.40, 12.41]0% [0%, 0%]0%0%-1.10+0.342026-01-08 → 2026-08-30
tmax00Znearestall29 2 QC10.19 [8.99, 11.42]3.20-10.19 [-11.42, -8.99]10.93 [9.42, 12.24]0% [0%, 0%]0%0%-1.10+0.342026-01-08 → 2026-08-30
tmax12Zbilinear30d23 2 QC10.69 [9.50, 12.32]3.29-10.69 [-12.32, -9.50]11.40 [10.06, 13.07]0% [0%, 0%]0%0%-1.23+0.322026-08-08 → 2026-08-30
tmax12Zbilinear90d23 2 QC10.69 [9.44, 13.16]3.29-10.69 [-13.16, -9.44]11.40 [10.00, 13.88]0% [0%, 0%]0%0%-1.23+0.322026-08-08 → 2026-08-30
tmax12Zbilinear365d28 2 QC10.15 [8.63, 11.97]3.48-10.15 [-11.97, -8.63]10.97 [9.45, 12.67]0% [0%, 0%]0%0%-1.04+0.302026-01-08 → 2026-08-30
tmax12Zbilinearall28 2 QC10.15 [8.45, 11.85]3.48-10.15 [-11.85, -8.45]10.97 [9.30, 12.63]0% [0%, 0%]0%0%-1.04+0.302026-01-08 → 2026-08-30
tmax12Znearest30d23 2 QC10.83 [9.60, 12.49]3.37-10.83 [-12.49, -9.60]11.56 [10.21, 13.26]0% [0%, 0%]0%0%-1.26+0.302026-08-08 → 2026-08-30
tmax12Znearest90d23 2 QC10.83 [9.53, 13.45]3.37-10.83 [-13.45, -9.53]11.56 [10.13, 14.04]0% [0%, 0%]0%0%-1.26+0.302026-08-08 → 2026-08-30
tmax12Znearest365d28 2 QC10.29 [8.76, 12.15]3.57-10.29 [-12.15, -8.76]11.12 [9.58, 12.86]0% [0%, 0%]0%0%-1.07+0.282026-01-08 → 2026-08-30
tmax12Znearestall28 2 QC10.29 [8.56, 12.05]3.57-10.29 [-12.05, -8.56]11.12 [9.39, 12.83]0% [0%, 0%]0%0%-1.07+0.282026-01-08 → 2026-08-30
tmin00Zbilinear30d23 2 QC3.15 [2.00, 4.50]2.91+1.56 [-0.06, 3.56]3.93 [2.48, 5.45]26% [4%, 52%]39%52%+0.26+0.302026-08-08 → 2026-08-30
tmin00Zbilinear90d23 2 QC3.15 [1.91, 4.86]2.91+1.56 [-0.34, 4.17]3.93 [2.36, 5.93]26% [0%, 56%]39%52%+0.26+0.302026-08-08 → 2026-08-30
tmin00Zbilinear365d29 2 QC3.53 [2.30, 4.99]3.10+2.05 [0.39, 4.15]4.37 [2.81, 5.87]21% [0%, 45%]34%45%+0.27+0.362026-01-08 → 2026-08-30
tmin00Zbilinearall29 2 QC3.53 [2.35, 5.06]3.10+2.05 [0.37, 4.28]4.37 [2.92, 5.96]21% [0%, 44%]34%45%+0.27+0.362026-01-08 → 2026-08-30
tmin00Znearest30d23 2 QC3.16 [2.01, 4.53]2.94+1.50 [-0.13, 3.53]3.95 [2.48, 5.45]13% [0%, 25%]39%52%+0.26+0.302026-08-08 → 2026-08-30
tmin00Znearest90d23 2 QC3.16 [1.93, 4.91]2.94+1.50 [-0.44, 4.13]3.95 [2.39, 5.93]13% [0%, 27%]39%52%+0.26+0.302026-08-08 → 2026-08-30
tmin00Znearest365d29 2 QC3.58 [2.32, 5.07]3.14+2.02 [0.36, 4.09]4.41 [2.83, 5.86]10% [0%, 22%]34%45%+0.26+0.352026-01-08 → 2026-08-30
tmin00Znearestall29 2 QC3.58 [2.36, 5.13]3.14+2.02 [0.32, 4.28]4.41 [3.00, 5.98]10% [0%, 22%]34%45%+0.26+0.352026-01-08 → 2026-08-30
tmin12Zbilinear30d23 2 QC3.25 [2.60, 4.16]3.03+1.22 [-0.93, 3.56]3.71 [3.02, 4.57]4% [0%, 12%]35%57%+0.24+0.272026-08-08 → 2026-08-30
tmin12Zbilinear90d23 2 QC3.25 [2.54, 4.39]3.03+1.22 [-1.28, 4.21]3.71 [2.91, 4.74]4% [0%, 12%]35%57%+0.24+0.272026-08-08 → 2026-08-30
tmin12Zbilinear365d28 2 QC4.07 [2.79, 6.30]3.65+2.08 [-0.33, 5.13]5.06 [3.21, 7.50]4% [0%, 11%]29%46%+0.15+0.242026-01-08 → 2026-08-30
tmin12Zbilinearall28 2 QC4.07 [2.82, 6.61]3.65+2.08 [-0.42, 5.18]5.06 [3.28, 7.79]4% [0%, 10%]29%46%+0.15+0.242026-01-08 → 2026-08-30
tmin12Znearest30d23 2 QC3.27 [2.64, 4.15]3.07+1.15 [-1.04, 3.51]3.72 [3.04, 4.53]4% [0%, 12%]35%52%+0.23+0.272026-08-08 → 2026-08-30
tmin12Znearest90d23 2 QC3.27 [2.60, 4.38]3.07+1.15 [-1.41, 4.20]3.72 [2.98, 4.67]4% [0%, 12%]35%52%+0.23+0.272026-08-08 → 2026-08-30
tmin12Znearest365d28 2 QC4.10 [2.81, 6.31]3.70+2.04 [-0.44, 5.17]5.09 [3.23, 7.56]4% [0%, 11%]29%43%+0.14+0.232026-01-08 → 2026-08-30
tmin12Znearestall28 2 QC4.10 [2.87, 6.67]3.70+2.04 [-0.52, 5.20]5.09 [3.31, 7.85]4% [0%, 10%]29%43%+0.14+0.232026-01-08 → 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 7, 00Z bilinear tmax+25+12.50-12.5-252026-08-08: -9.24 °F2026-08-09: -13.52 °F2026-08-10: -7.32 °F2026-08-11: -6.36 °F2026-08-12: -5.54 °F2026-08-13: -7.44 °F2026-08-14: -18.92 °F2026-08-15: -12.02 °F2026-08-16: -8.51 °F2026-08-17: -7.28 °F2026-08-18: -20.66 °F2026-08-19: -8.53 °F2026-08-20: -11.34 °F2026-08-21: -13.12 °F2026-08-22: -6.24 °F2026-08-23: -6.08 °F2026-08-24: -13.7 °F2026-08-25: -9.29 °F2026-08-26: -4.36 °F2026-08-27: -8.6 °F2026-08-28: -14.18 °F2026-08-29: -13.35 °F2026-08-30: -11.65 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-11.65
2026-08-29-13.35
2026-08-28-14.18
2026-08-27-8.60
2026-08-26-4.36
2026-08-25-9.29
2026-08-24-13.70
2026-08-23-6.08
2026-08-22-6.24
2026-08-21-13.12
2026-08-20-11.34
2026-08-19-8.53
2026-08-18-20.66
2026-08-17-7.28
2026-08-16-8.51
2026-08-15-12.02
2026-08-14-18.92
2026-08-13-7.44
2026-08-12-5.54
2026-08-11-6.36
2026-08-10-7.32
2026-08-09-13.52
2026-08-08-9.24

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KOKC, lead day 7-25 to -22.5 °F: 0 days-22.5 to -20 °F: 1 day-20 to -17.5 °F: 1 day-17.5 to -15 °F: 0 days-15 to -12.5 °F: 6 days-12.5 to -10 °F: 4 days-10 to -7.5 °F: 7 days-7.5 to -5 °F: 9 days-5 to -2.5 °F: 1 day-2.5 to 0 °F: 0 days0 to 2.5 °F: 0 days2.5 to 5 °F: 0 days5 to 7.5 °F: 0 days7.5 to 10 °F: 0 days10 to 12.5 °F: 0 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| 9.24 · P90 |e| 13.8 °F-250+25 °Fn = 29 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
-25.00-22.500
-22.50-20.001
-20.00-17.501
-17.50-15.000
-15.00-12.506
-12.50-10.004
-10.00-7.507
-7.50-5.009
-5.00-2.501
-2.50+0.000
+0.00+2.500
+2.50+5.000
+5.00+7.500
+7.50+10.000
+10.00+12.500
+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
2026-082310.31 -10.31
2026-0168.65 -8.65

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 28
GraphCast (IFS init)2026-01-08 → 2026-08-30 28

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 23 +5.29 [2.18, 6.76] yes
NCEP GFS 23 +6.93 [5.85, 8.26] yes
ECMWF IFS HRES 18 +8.59 [7.04, 10.50] yes
Persistence (baseline) 23 +5.53 [2.62, 8.14] yes

Cite this page

ShortCastCheck, KOKC graphcast_ifs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KOKC/model/graphcast_ifs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model graphcast_ifs, lead day 7. 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/7/

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