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 6

KOKC · gfs · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d24 2 QC4.23 [3.15, 5.22]4.07+1.27 [-0.25, 2.68]5.54 [4.01, 6.58]21% [13%, 30%]38%50%-0.19-0.132026-08-07 → 2026-08-30
tmax00Zbilinear90d24 2 QC4.23 [2.95, 5.16]4.07+1.27 [-0.50, 2.83]5.54 [3.74, 6.51]21% [12%, 31%]38%50%-0.19-0.132026-08-07 → 2026-08-30
tmax00Zbilinear365d24 2 QC4.23 [2.93, 5.27]4.07+1.27 [-0.70, 2.93]5.54 [3.69, 6.67]21% [12%, 33%]38%50%-0.19-0.132026-08-07 → 2026-08-30
tmax00Zbilinearall24 2 QC4.23 [2.96, 5.18]4.07+1.27 [-0.55, 2.81]5.54 [3.71, 6.65]21% [12%, 33%]38%50%-0.19-0.132026-08-07 → 2026-08-30
tmax00Znearest30d24 2 QC4.35 [3.11, 5.44]4.10+1.38 [-0.01, 2.62]5.62 [3.90, 6.76]12% [0%, 21%]25%50%-0.23-0.142026-08-07 → 2026-08-30
tmax00Znearest90d24 2 QC4.35 [2.94, 5.37]4.10+1.38 [-0.24, 2.80]5.62 [3.64, 6.71]12% [0%, 22%]25%50%-0.23-0.142026-08-07 → 2026-08-30
tmax00Znearest365d24 2 QC4.35 [2.90, 5.57]4.10+1.38 [-0.36, 2.85]5.62 [3.52, 6.82]12% [0%, 22%]25%50%-0.23-0.142026-08-07 → 2026-08-30
tmax00Znearestall24 2 QC4.35 [2.98, 5.44]4.10+1.38 [-0.26, 2.79]5.62 [3.66, 6.78]12% [0%, 25%]25%50%-0.23-0.142026-08-07 → 2026-08-30
tmax12Zbilinear30d24 2 QC4.51 [2.79, 6.15]4.21+0.91 [-1.10, 2.70]6.18 [3.92, 7.80]21% [4%, 46%]38%50%-0.27-0.172026-08-07 → 2026-08-30
tmax12Zbilinear90d24 2 QC4.51 [2.46, 6.19]4.21+0.91 [-1.39, 2.75]6.18 [3.56, 7.88]21% [0%, 55%]38%50%-0.27-0.172026-08-07 → 2026-08-30
tmax12Zbilinear365d24 2 QC4.51 [2.50, 6.40]4.21+0.91 [-1.37, 2.95]6.18 [3.45, 8.06]21% [0%, 56%]38%50%-0.27-0.172026-08-07 → 2026-08-30
tmax12Zbilinearall24 2 QC4.51 [2.44, 6.14]4.21+0.91 [-1.33, 2.90]6.18 [3.40, 7.82]21% [0%, 50%]38%50%-0.27-0.172026-08-07 → 2026-08-30
tmax12Znearest30d24 2 QC4.69 [3.07, 6.27]4.31+1.08 [-0.85, 2.78]6.33 [4.00, 7.98]8% [0%, 21%]38%50%-0.32-0.202026-08-07 → 2026-08-30
tmax12Znearest90d24 2 QC4.69 [2.75, 6.36]4.31+1.08 [-1.11, 2.87]6.33 [3.67, 8.06]8% [0%, 22%]38%50%-0.32-0.202026-08-07 → 2026-08-30
tmax12Znearest365d24 2 QC4.69 [2.75, 6.52]4.31+1.08 [-1.17, 2.97]6.33 [3.62, 8.17]8% [0%, 24%]38%50%-0.32-0.202026-08-07 → 2026-08-30
tmax12Znearestall24 2 QC4.69 [2.77, 6.27]4.31+1.08 [-0.99, 2.95]6.33 [3.62, 8.06]8% [0%, 22%]38%50%-0.32-0.202026-08-07 → 2026-08-30
tmin00Zbilinear30d24 2 QC5.62 [4.61, 7.08]3.60+4.01 [2.13, 6.51]6.10 [5.03, 7.49]0% [0%, 0%]4%21%-0.43+0.102026-08-07 → 2026-08-30
tmin00Zbilinear90d24 2 QC5.62 [4.53, 7.60]3.60+4.01 [1.92, 7.46]6.10 [4.97, 7.95]0% [0%, 0%]4%21%-0.43+0.102026-08-07 → 2026-08-30
tmin00Zbilinear365d24 2 QC5.62 [4.54, 7.54]3.60+4.01 [1.59, 7.44]6.10 [4.96, 7.84]0% [0%, 0%]4%21%-0.43+0.102026-08-07 → 2026-08-30
tmin00Zbilinearall24 2 QC5.62 [4.41, 7.60]3.60+4.01 [1.75, 7.60]6.10 [4.80, 7.84]0% [0%, 0%]4%21%-0.43+0.102026-08-07 → 2026-08-30
tmin00Znearest30d24 2 QC6.05 [5.01, 7.47]3.87+4.30 [2.27, 6.84]6.52 [5.46, 7.85]4% [0%, 12%]8%17%-0.54+0.032026-08-07 → 2026-08-30
tmin00Znearest90d24 2 QC6.05 [4.95, 7.86]3.87+4.30 [2.05, 7.67]6.52 [5.40, 8.24]4% [0%, 13%]8%17%-0.54+0.032026-08-07 → 2026-08-30
tmin00Znearest365d24 2 QC6.05 [4.91, 7.78]3.87+4.30 [1.75, 7.65]6.52 [5.38, 8.15]4% [0%, 14%]8%17%-0.54+0.032026-08-07 → 2026-08-30
tmin00Znearestall24 2 QC6.05 [4.81, 7.83]3.87+4.30 [1.93, 7.74]6.52 [5.23, 8.13]4% [0%, 14%]8%17%-0.54+0.032026-08-07 → 2026-08-30
tmin12Zbilinear30d24 2 QC4.62 [3.32, 6.12]3.90+2.65 [1.01, 4.95]5.51 [4.26, 6.79]12% [0%, 22%]25%38%-0.18+0.022026-08-07 → 2026-08-30
tmin12Zbilinear90d24 2 QC4.62 [3.28, 6.44]3.90+2.65 [0.88, 6.32]5.51 [4.17, 7.10]12% [0%, 22%]25%38%-0.18+0.022026-08-07 → 2026-08-30
tmin12Zbilinear365d24 2 QC4.62 [3.07, 6.43]3.90+2.65 [0.77, 6.11]5.51 [4.01, 6.99]12% [0%, 22%]25%38%-0.18+0.022026-08-07 → 2026-08-30
tmin12Zbilinearall24 2 QC4.62 [2.92, 6.63]3.90+2.65 [0.73, 6.50]5.51 [3.83, 7.23]12% [0%, 24%]25%38%-0.18+0.022026-08-07 → 2026-08-30
tmin12Znearest30d24 2 QC4.82 [3.46, 6.33]4.01+2.84 [1.08, 5.15]5.77 [4.46, 7.04]17% [5%, 26%]25%33%-0.23-0.002026-08-07 → 2026-08-30
tmin12Znearest90d24 2 QC4.82 [3.40, 6.60]4.01+2.84 [0.98, 6.30]5.77 [4.39, 7.27]17% [0%, 27%]25%33%-0.23-0.002026-08-07 → 2026-08-30
tmin12Znearest365d24 2 QC4.82 [3.23, 6.64]4.01+2.84 [0.90, 6.24]5.77 [4.13, 7.17]17% [0%, 29%]25%33%-0.23-0.002026-08-07 → 2026-08-30
tmin12Znearestall24 2 QC4.82 [3.00, 6.74]4.01+2.84 [0.82, 6.62]5.77 [3.96, 7.39]17% [0%, 29%]25%33%-0.23-0.002026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: +5.8 °F2026-08-08: -4.44 °F2026-08-09: -2.25 °F2026-08-10: -0.41 °F2026-08-11: +1.89 °F2026-08-12: +1.7 °F2026-08-13: -9.95 °F2026-08-14: +0.67 °F2026-08-15: +3.28 °F2026-08-16: +3.94 °F2026-08-17: +10.86 °F2026-08-18: +2.8 °F2026-08-19: +4.9 °F2026-08-20: -10.77 °F2026-08-21: -0.61 °F2026-08-22: -1.56 °F2026-08-23: +12.37 °F2026-08-24: +2.41 °F2026-08-25: +0.36 °F2026-08-26: +6.71 °F2026-08-27: +7.42 °F2026-08-28: -1.77 °F2026-08-29: -3.72 °F2026-08-30: +0.85 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.85
2026-08-29-3.72
2026-08-28-1.77
2026-08-27+7.42
2026-08-26+6.71
2026-08-25+0.36
2026-08-24+2.41
2026-08-23+12.37
2026-08-22-1.56
2026-08-21-0.61
2026-08-20-10.77
2026-08-19+4.90
2026-08-18+2.80
2026-08-17+10.86
2026-08-16+3.94
2026-08-15+3.28
2026-08-14+0.67
2026-08-13-9.95
2026-08-12+1.70
2026-08-11+1.89
2026-08-10-0.41
2026-08-09-2.25
2026-08-08-4.44
2026-08-07+5.80

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KOKC, lead day 6-20 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: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 0 days-6 to -4 °F: 1 day-4 to -2 °F: 2 days-2 to 0 °F: 4 days0 to 2 °F: 5 days2 to 4 °F: 4 days4 to 6 °F: 2 days6 to 8 °F: 2 days8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 1 day14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.04 · P90 |e| 10.52 °F-200+20 °Fn = 24 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
-12.00-10.001
-10.00-8.001
-8.00-6.000
-6.00-4.001
-4.00-2.002
-2.00+0.004
+0.00+2.005
+2.00+4.004
+4.00+6.002
+6.00+8.002
+8.00+10.000
+10.00+12.001
+12.00+14.001
+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
2026-08244.23 +1.27

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24

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 24 -0.30 [-2.34, 1.04] no
GraphCast (IFS init) 24 -5.22 [-7.30, -3.72] yes
ECMWF IFS HRES 19 +1.93 [-0.71, 3.12] no
Persistence (baseline) 24 +0.68 [-1.42, 2.22] no

Cite this page

ShortCastCheck, KOKC gfs lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KOKC/model/gfs/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KOKC (Oklahoma City), model gfs, lead day 6. 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/6/

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