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

Houston Bush · NCEP GFS · lead day 8

KIAH · gfs · lead 8

Target day = initialization date + 8 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, 1 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
tmax00Zbilinear30d22 1 QC2.44 [1.52, 3.53]2.42-0.76 [-2.89, 1.52]3.20 [1.89, 4.24]27% [12%, 40%]55%73%+0.30+0.282026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC2.44 [1.50, 3.73]2.42-0.76 [-2.93, 1.94]3.20 [1.88, 4.37]27% [11%, 40%]55%73%+0.30+0.282026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC2.44 [1.50, 3.79]2.42-0.76 [-3.15, 1.91]3.20 [1.88, 4.49]27% [10%, 41%]55%73%+0.30+0.282026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC2.44 [1.46, 3.95]2.42-0.76 [-3.38, 1.89]3.20 [1.86, 4.60]27% [0%, 43%]55%73%+0.30+0.282026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC2.59 [1.62, 3.73]2.53-0.88 [-3.09, 1.51]3.33 [2.08, 4.38]18% [4%, 32%]45%68%+0.26+0.252026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC2.59 [1.57, 3.92]2.53-0.88 [-3.17, 2.04]3.33 [1.98, 4.52]18% [0%, 33%]45%68%+0.26+0.252026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC2.59 [1.53, 4.02]2.53-0.88 [-3.43, 1.97]3.33 [1.96, 4.68]18% [0%, 33%]45%68%+0.26+0.252026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC2.59 [1.49, 4.14]2.53-0.88 [-3.65, 1.87]3.33 [1.88, 4.75]18% [0%, 33%]45%68%+0.26+0.252026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC2.40 [1.51, 3.33]2.34-0.69 [-2.16, 1.02]3.03 [1.92, 3.82]27% [10%, 41%]50%68%+0.31+0.302026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC2.40 [1.37, 3.55]2.34-0.69 [-2.28, 1.50]3.03 [1.71, 3.98]27% [7%, 40%]50%68%+0.31+0.302026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC2.40 [1.32, 3.59]2.34-0.69 [-2.52, 1.47]3.03 [1.56, 4.02]27% [0%, 43%]50%68%+0.31+0.302026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC2.40 [1.33, 3.57]2.34-0.69 [-2.53, 1.39]3.03 [1.56, 4.00]27% [0%, 42%]50%68%+0.31+0.302026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC2.39 [1.51, 3.34]2.30-0.74 [-2.12, 0.84]2.98 [1.87, 3.89]32% [18%, 47%]50%68%+0.32+0.312026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC2.39 [1.35, 3.51]2.30-0.74 [-2.22, 1.25]2.98 [1.68, 4.01]32% [12%, 47%]50%68%+0.32+0.312026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC2.39 [1.33, 3.64]2.30-0.74 [-2.48, 1.20]2.98 [1.56, 3.98]32% [11%, 50%]50%68%+0.32+0.312026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC2.39 [1.34, 3.67]2.30-0.74 [-2.50, 1.16]2.98 [1.56, 4.01]32% [11%, 50%]50%68%+0.32+0.312026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC2.98 [1.72, 4.18]2.58+2.67 [1.06, 4.14]3.91 [2.68, 4.77]36% [16%, 57%]45%55%+0.12+0.242026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC2.98 [1.63, 4.23]2.58+2.67 [0.92, 4.19]3.91 [2.60, 4.85]36% [14%, 60%]45%55%+0.12+0.242026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC2.98 [1.45, 4.29]2.58+2.67 [0.81, 4.28]3.91 [2.35, 4.85]36% [12%, 62%]45%55%+0.12+0.242026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC2.98 [1.36, 4.26]2.58+2.67 [0.64, 4.26]3.91 [2.24, 4.85]36% [13%, 62%]45%55%+0.12+0.242026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC3.10 [1.95, 4.19]2.61+2.60 [1.00, 4.03]3.92 [2.84, 4.77]36% [16%, 57%]41%55%+0.09+0.232026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC3.10 [1.92, 4.21]2.61+2.60 [0.89, 4.06]3.92 [2.71, 4.76]36% [14%, 60%]41%55%+0.09+0.232026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC3.10 [1.76, 4.29]2.61+2.60 [0.70, 4.22]3.92 [2.59, 4.81]36% [12%, 62%]41%55%+0.09+0.232026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC3.10 [1.67, 4.25]2.61+2.60 [0.55, 4.22]3.92 [2.45, 4.84]36% [13%, 62%]41%55%+0.09+0.232026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC3.65 [2.61, 4.76]2.59+3.03 [1.18, 4.74]4.35 [3.21, 5.30]18% [0%, 32%]32%45%-0.07+0.232026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC3.65 [2.53, 4.86]2.59+3.03 [1.06, 4.86]4.35 [3.21, 5.38]18% [0%, 33%]32%45%-0.07+0.232026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC3.65 [2.36, 4.89]2.59+3.03 [0.85, 4.88]4.35 [3.02, 5.37]18% [0%, 33%]32%45%-0.07+0.232026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC3.65 [2.26, 4.86]2.59+3.03 [0.56, 4.86]4.35 [2.55, 5.31]18% [0%, 36%]32%45%-0.07+0.232026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC3.70 [2.85, 4.62]2.70+2.85 [0.89, 4.61]4.45 [3.66, 5.23]18% [7%, 31%]32%41%-0.09+0.202026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC3.70 [2.80, 4.79]2.70+2.85 [0.64, 4.79]4.45 [3.64, 5.32]18% [6%, 33%]32%41%-0.09+0.202026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC3.70 [2.67, 4.78]2.70+2.85 [0.45, 4.78]4.45 [3.52, 5.30]18% [6%, 33%]32%41%-0.09+0.202026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC3.70 [2.61, 4.76]2.70+2.85 [0.15, 4.76]4.45 [3.29, 5.23]18% [0%, 33%]32%41%-0.09+0.202026-08-09 → 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 KIAH, lead day 8, 00Z bilinear tmax+10+50-5-102026-08-09: +5.35 °F2026-08-10: +0.9 °F2026-08-11: +2.14 °F2026-08-12: +0.47 °F2026-08-13: +1.39 °F2026-08-14: +4.13 °F2026-08-15: -1.12 °F2026-08-16: -0.73 °F2026-08-17: -0.3 °F2026-08-18: -1.07 °F2026-08-19: +1.74 °F2026-08-20: -1.09 °F2026-08-21: -4.99 °F2026-08-22: -5.04 °F2026-08-23: -6.28 °F2026-08-24: -7.28 °F2026-08-25: -2.65 °F2026-08-26: +0.33 °F2026-08-27: -2.75 °F2026-08-28: -0.02 °F2026-08-29: +2.04 °F2026-08-30: -1.9 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.90
2026-08-29+2.04
2026-08-28-0.02
2026-08-27-2.75
2026-08-26+0.33
2026-08-25-2.65
2026-08-24-7.28
2026-08-23-6.28
2026-08-22-5.04
2026-08-21-4.99
2026-08-20-1.09
2026-08-19+1.74
2026-08-18-1.07
2026-08-17-0.30
2026-08-16-0.73
2026-08-15-1.12
2026-08-14+4.13
2026-08-13+1.39
2026-08-12+0.47
2026-08-11+2.14
2026-08-10+0.90
2026-08-09+5.35

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KIAH, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 1 day-5 to -4 °F: 1 day-4 to -3 °F: 0 days-3 to -2 °F: 2 days-2 to -1 °F: 4 days-1 to 0 °F: 3 days0 to 1 °F: 3 days1 to 2 °F: 2 days2 to 3 °F: 2 days3 to 4 °F: 0 days4 to 5 °F: 1 day5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 1.82 · P90 |e| 5.32 °F-100+10 °Fn = 22 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
-10.00-9.000
-9.00-8.000
-8.00-7.001
-7.00-6.001
-6.00-5.001
-5.00-4.001
-4.00-3.000
-3.00-2.002
-2.00-1.004
-1.00+0.003
+0.00+1.003
+1.00+2.002
+2.00+3.002
+3.00+4.000
+4.00+5.001
+5.00+6.001
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08222.44 -0.76

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22

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 22 -1.00 [-1.91, 0.40] no
GraphCast (IFS init) 22 -3.53 [-5.03, -0.70] yes
ECMWF IFS HRES 17 -1.52 [-2.94, 2.88] no
Persistence (baseline) 22 -1.06 [-2.61, 0.37] no

Cite this page

ShortCastCheck, KIAH gfs lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/gfs/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model gfs, lead day 8. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KIAH/model/gfs/lead/8/

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

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