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 · NCEP GFS · lead day 4

KOKC · gfs · lead 4

Target day = initialization date + 4 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, gfs-0p25, starting 2026-08-01 — 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
tmax00Zbilinear30d26 2 QC2.99 [1.93, 4.24]2.54+1.93 [1.06, 2.99]3.91 [2.34, 5.35]27% [14%, 37%]38%65%+0.24+0.352026-08-05 → 2026-08-30
tmax00Zbilinear90d26 2 QC2.99 [1.87, 4.35]2.54+1.93 [1.08, 3.07]3.91 [2.25, 5.42]27% [12%, 37%]38%65%+0.24+0.352026-08-05 → 2026-08-30
tmax00Zbilinear365d26 2 QC2.99 [1.77, 4.48]2.54+1.93 [1.02, 3.19]3.91 [2.13, 5.56]27% [12%, 38%]38%65%+0.24+0.352026-08-05 → 2026-08-30
tmax00Zbilinearall26 2 QC2.99 [1.81, 4.50]2.54+1.93 [1.04, 3.29]3.91 [2.20, 5.60]27% [11%, 38%]38%65%+0.24+0.352026-08-05 → 2026-08-30
tmax00Znearest30d26 2 QC3.17 [2.15, 4.35]2.60+2.25 [1.47, 3.19]4.10 [2.66, 5.42]23% [11%, 33%]46%58%+0.20+0.342026-08-05 → 2026-08-30
tmax00Znearest90d26 2 QC3.17 [2.06, 4.48]2.60+2.25 [1.45, 3.27]4.10 [2.58, 5.56]23% [11%, 34%]46%58%+0.20+0.342026-08-05 → 2026-08-30
tmax00Znearest365d26 2 QC3.17 [1.98, 4.62]2.60+2.25 [1.43, 3.33]4.10 [2.46, 5.61]23% [9%, 36%]46%58%+0.20+0.342026-08-05 → 2026-08-30
tmax00Znearestall26 2 QC3.17 [2.01, 4.61]2.60+2.25 [1.41, 3.36]4.10 [2.49, 5.61]23% [10%, 35%]46%58%+0.20+0.342026-08-05 → 2026-08-30
tmax12Zbilinear30d26 2 QC3.17 [2.02, 4.52]2.82+2.18 [1.01, 3.43]4.13 [2.79, 5.29]31% [11%, 48%]46%58%+0.20+0.282026-08-05 → 2026-08-30
tmax12Zbilinear90d26 2 QC3.17 [1.93, 4.62]2.82+2.18 [0.87, 3.48]4.13 [2.60, 5.32]31% [9%, 50%]46%58%+0.20+0.282026-08-05 → 2026-08-30
tmax12Zbilinear365d26 2 QC3.17 [1.76, 4.70]2.82+2.18 [0.78, 3.61]4.13 [2.38, 5.40]31% [6%, 52%]46%58%+0.20+0.282026-08-05 → 2026-08-30
tmax12Zbilinearall26 2 QC3.17 [1.82, 4.68]2.82+2.18 [0.87, 3.67]4.13 [2.38, 5.43]31% [0%, 52%]46%58%+0.20+0.282026-08-05 → 2026-08-30
tmax12Znearest30d26 2 QC3.58 [2.34, 4.97]2.94+2.41 [1.12, 3.71]4.49 [3.13, 5.65]15% [4%, 28%]38%46%+0.10+0.252026-08-05 → 2026-08-30
tmax12Znearest90d26 2 QC3.58 [2.19, 5.08]2.94+2.41 [0.97, 3.77]4.49 [2.95, 5.72]15% [0%, 29%]38%46%+0.10+0.252026-08-05 → 2026-08-30
tmax12Znearest365d26 2 QC3.58 [2.01, 5.27]2.94+2.41 [0.87, 3.87]4.49 [2.70, 5.83]15% [0%, 29%]38%46%+0.10+0.252026-08-05 → 2026-08-30
tmax12Znearestall26 2 QC3.58 [2.11, 5.34]2.94+2.41 [0.93, 3.94]4.49 [2.64, 5.85]15% [0%, 29%]38%46%+0.10+0.252026-08-05 → 2026-08-30
tmin00Zbilinear30d26 2 QC5.23 [4.16, 6.25]2.72+4.84 [3.60, 6.15]5.96 [5.03, 6.75]12% [0%, 27%]15%23%-0.21+0.362026-08-05 → 2026-08-30
tmin00Zbilinear90d26 2 QC5.23 [4.03, 6.42]2.72+4.84 [3.42, 6.37]5.96 [4.87, 6.80]12% [0%, 28%]15%23%-0.21+0.362026-08-05 → 2026-08-30
tmin00Zbilinear365d26 2 QC5.23 [3.92, 6.49]2.72+4.84 [3.23, 6.49]5.96 [4.78, 6.80]12% [0%, 30%]15%23%-0.21+0.362026-08-05 → 2026-08-30
tmin00Zbilinearall26 2 QC5.23 [4.01, 6.48]2.72+4.84 [3.29, 6.40]5.96 [4.81, 6.87]12% [0%, 31%]15%23%-0.21+0.362026-08-05 → 2026-08-30
tmin00Znearest30d26 2 QC5.61 [4.64, 6.50]2.92+5.18 [3.94, 6.37]6.37 [5.45, 7.04]8% [0%, 19%]12%23%-0.30+0.312026-08-05 → 2026-08-30
tmin00Znearest90d26 2 QC5.61 [4.51, 6.57]2.92+5.18 [3.80, 6.49]6.37 [5.41, 7.01]8% [0%, 19%]12%23%-0.30+0.312026-08-05 → 2026-08-30
tmin00Znearest365d26 2 QC5.61 [4.34, 6.59]2.92+5.18 [3.57, 6.57]6.37 [5.27, 7.05]8% [0%, 20%]12%23%-0.30+0.312026-08-05 → 2026-08-30
tmin00Znearestall26 2 QC5.61 [4.49, 6.62]2.92+5.18 [3.62, 6.56]6.37 [5.33, 7.10]8% [0%, 20%]12%23%-0.30+0.312026-08-05 → 2026-08-30
tmin12Zbilinear30d26 2 QC4.31 [3.26, 5.49]2.13+4.26 [3.20, 5.48]4.98 [4.04, 5.85]19% [0%, 42%]19%31%+0.00+0.502026-08-05 → 2026-08-30
tmin12Zbilinear90d26 2 QC4.31 [3.19, 5.76]2.13+4.26 [3.13, 5.76]4.98 [3.93, 5.94]19% [0%, 43%]19%31%+0.00+0.502026-08-05 → 2026-08-30
tmin12Zbilinear365d26 2 QC4.31 [3.01, 5.66]2.13+4.26 [2.92, 5.66]4.98 [3.74, 5.91]19% [0%, 45%]19%31%+0.00+0.502026-08-05 → 2026-08-30
tmin12Zbilinearall26 2 QC4.31 [3.05, 5.76]2.13+4.26 [2.99, 5.76]4.98 [3.72, 5.95]19% [0%, 45%]19%31%+0.00+0.502026-08-05 → 2026-08-30
tmin12Znearest30d26 2 QC4.54 [3.55, 5.71]2.11+4.53 [3.53, 5.70]5.21 [4.31, 6.04]15% [0%, 32%]19%31%-0.05+0.502026-08-05 → 2026-08-30
tmin12Znearest90d26 2 QC4.54 [3.49, 5.97]2.11+4.53 [3.49, 5.97]5.21 [4.29, 6.15]15% [0%, 33%]19%31%-0.05+0.502026-08-05 → 2026-08-30
tmin12Znearest365d26 2 QC4.54 [3.32, 5.92]2.11+4.53 [3.28, 5.92]5.21 [4.09, 6.11]15% [0%, 36%]19%31%-0.05+0.502026-08-05 → 2026-08-30
tmin12Znearestall26 2 QC4.54 [3.38, 6.01]2.11+4.53 [3.36, 6.01]5.21 [4.07, 6.16]15% [0%, 33%]19%31%-0.05+0.502026-08-05 → 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 NCEP GFS at KOKC, lead day 4, 00Z bilinear tmax+20+100-10-202026-08-05: +4.37 °F2026-08-06: +2.3 °F2026-08-07: +3.42 °F2026-08-08: -1.88 °F2026-08-09: +1.06 °F2026-08-10: +0.16 °F2026-08-11: +1.46 °F2026-08-12: +2.12 °F2026-08-13: -0.61 °F2026-08-14: +0.7 °F2026-08-15: +3.92 °F2026-08-16: +4.24 °F2026-08-17: -2.17 °F2026-08-18: +0.98 °F2026-08-19: +5.77 °F2026-08-20: -5.76 °F2026-08-21: +0.82 °F2026-08-22: +9.06 °F2026-08-23: +10.52 °F2026-08-24: +2.62 °F2026-08-25: +0.7 °F2026-08-26: +4.4 °F2026-08-27: -2.91 °F2026-08-28: +2.76 °F2026-08-29: -0.51 °F2026-08-30: +2.6 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+2.60
2026-08-29-0.51
2026-08-28+2.76
2026-08-27-2.91
2026-08-26+4.40
2026-08-25+0.70
2026-08-24+2.62
2026-08-23+10.52
2026-08-22+9.06
2026-08-21+0.82
2026-08-20-5.76
2026-08-19+5.77
2026-08-18+0.98
2026-08-17-2.17
2026-08-16+4.24
2026-08-15+3.92
2026-08-14+0.70
2026-08-13-0.61
2026-08-12+2.12
2026-08-11+1.46
2026-08-10+0.16
2026-08-09+1.06
2026-08-08-1.88
2026-08-07+3.42
2026-08-06+2.30
2026-08-05+4.37

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KOKC, lead day 4-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 1 day-4 to -2 °F: 2 days-2 to 0 °F: 3 days0 to 2 °F: 7 days2 to 4 °F: 7 days4 to 6 °F: 4 days6 to 8 °F: 0 days8 to 10 °F: 1 day10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 2.45 · P90 |e| 5.76 °F-200+20 °Fn = 26 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
-14.00-12.000
-12.00-10.000
-10.00-8.000
-8.00-6.000
-6.00-4.001
-4.00-2.002
-2.00+0.003
+0.00+2.007
+2.00+4.007
+4.00+6.004
+6.00+8.000
+8.00+10.001
+10.00+12.001
+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
2026-08262.99 +1.93

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-05 → 2026-08-30 26
NCEP GFS2026-08-05 → 2026-08-30 26
NCEP GFS2026-08-05 → 2026-08-30 26
NCEP GFS2026-08-05 → 2026-08-30 26

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means NCEP GFS has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 26 -0.93 [-3.24, 0.81] no
GraphCast (IFS init) 25 -5.43 [-7.41, -3.78] yes
ECMWF IFS HRES 20 -0.39 [-1.97, 1.45] no
Persistence (baseline) 26 -0.97 [-2.86, 0.14] no

Cite this page

ShortCastCheck, KOKC gfs lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KOKC/model/gfs/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model gfs, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KOKC/model/gfs/lead/4/

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