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 3

KIAH · gfs · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d27 1 QC2.13 [1.40, 2.84]2.06-0.37 [-2.03, 1.39]2.79 [1.87, 3.44]37% [15%, 58%]56%74%+0.10+0.132026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC2.13 [1.30, 2.88]2.06-0.37 [-2.14, 1.51]2.79 [1.73, 3.49]37% [14%, 63%]56%74%+0.10+0.132026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC2.13 [1.20, 2.99]2.06-0.37 [-2.30, 1.65]2.79 [1.54, 3.50]37% [14%, 60%]56%74%+0.10+0.132026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC2.13 [1.13, 2.95]2.06-0.37 [-2.34, 1.69]2.79 [1.53, 3.48]37% [12%, 64%]56%74%+0.10+0.132026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC2.04 [1.23, 2.82]2.00-0.46 [-2.05, 1.18]2.82 [1.80, 3.55]41% [17%, 68%]59%74%+0.14+0.162026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC2.04 [1.13, 2.92]2.00-0.46 [-2.20, 1.34]2.82 [1.65, 3.64]41% [14%, 73%]59%74%+0.14+0.162026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC2.04 [1.03, 3.05]2.00-0.46 [-2.33, 1.42]2.82 [1.42, 3.66]41% [14%, 71%]59%74%+0.14+0.162026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC2.04 [0.98, 3.01]2.00-0.46 [-2.38, 1.48]2.82 [1.40, 3.65]41% [12%, 75%]59%74%+0.14+0.162026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC1.97 [1.20, 2.66]1.85-0.47 [-1.91, 1.06]2.71 [1.58, 3.41]37% [15%, 64%]63%74%+0.17+0.222026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC1.97 [1.06, 2.71]1.85-0.47 [-2.03, 1.25]2.71 [1.34, 3.48]37% [14%, 67%]63%74%+0.17+0.222026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC1.97 [1.03, 2.75]1.85-0.47 [-2.22, 1.38]2.71 [1.33, 3.47]37% [11%, 67%]63%74%+0.17+0.222026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC1.97 [0.88, 2.73]1.85-0.47 [-2.17, 1.40]2.71 [1.16, 3.48]37% [10%, 75%]63%74%+0.17+0.222026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC1.98 [1.20, 2.68]1.83-0.45 [-1.76, 0.98]2.72 [1.52, 3.48]37% [20%, 60%]63%81%+0.17+0.232026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC1.98 [1.06, 2.73]1.83-0.45 [-1.86, 1.11]2.72 [1.35, 3.53]37% [20%, 61%]63%81%+0.17+0.232026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC1.98 [1.03, 2.77]1.83-0.45 [-2.03, 1.26]2.72 [1.30, 3.51]37% [19%, 64%]63%81%+0.17+0.232026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC1.98 [0.91, 2.73]1.83-0.45 [-2.02, 1.26]2.72 [1.25, 3.52]37% [17%, 70%]63%81%+0.17+0.232026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC3.61 [2.31, 4.84]2.09+3.58 [2.25, 4.84]4.38 [3.14, 5.40]26% [7%, 46%]33%37%-0.25+0.282026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC3.61 [2.22, 5.02]2.09+3.58 [2.17, 5.02]4.38 [2.96, 5.51]26% [0%, 48%]33%37%-0.25+0.282026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC3.61 [2.15, 5.01]2.09+3.58 [2.07, 5.01]4.38 [2.85, 5.57]26% [0%, 50%]33%37%-0.25+0.282026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC3.61 [2.07, 4.94]2.09+3.58 [2.00, 4.94]4.38 [2.83, 5.42]26% [0%, 50%]33%37%-0.25+0.282026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC3.65 [2.51, 4.80]1.94+3.64 [2.47, 4.80]4.38 [3.24, 5.35]19% [4%, 35%]30%37%-0.26+0.332026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC3.65 [2.43, 4.91]1.94+3.64 [2.38, 4.91]4.38 [3.06, 5.44]19% [0%, 34%]30%37%-0.26+0.332026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC3.65 [2.33, 4.90]1.94+3.64 [2.31, 4.90]4.38 [2.96, 5.49]19% [0%, 38%]30%37%-0.26+0.332026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC3.65 [2.25, 4.84]1.94+3.64 [2.25, 4.84]4.38 [2.93, 5.35]19% [0%, 35%]30%37%-0.26+0.332026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC3.63 [2.41, 4.77]1.97+3.56 [2.30, 4.77]4.31 [3.16, 5.30]19% [5%, 32%]30%37%-0.26+0.322026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC3.63 [2.34, 4.90]1.97+3.56 [2.22, 4.90]4.31 [2.97, 5.36]19% [0%, 31%]30%37%-0.26+0.322026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC3.63 [2.28, 4.88]1.97+3.56 [2.14, 4.88]4.31 [2.89, 5.40]19% [0%, 33%]30%37%-0.26+0.322026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC3.63 [2.17, 4.85]1.97+3.56 [2.09, 4.85]4.31 [2.85, 5.32]19% [0%, 32%]30%37%-0.26+0.322026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC3.66 [2.60, 4.72]1.86+3.62 [2.53, 4.72]4.33 [3.24, 5.28]15% [4%, 24%]30%37%-0.27+0.362026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC3.66 [2.51, 4.83]1.86+3.62 [2.40, 4.83]4.33 [3.07, 5.36]15% [0%, 25%]30%37%-0.27+0.362026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC3.66 [2.44, 4.84]1.86+3.62 [2.37, 4.84]4.33 [2.98, 5.37]15% [0%, 25%]30%37%-0.27+0.362026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC3.66 [2.37, 4.76]1.86+3.62 [2.33, 4.76]4.33 [2.95, 5.30]15% [0%, 26%]30%37%-0.27+0.362026-08-04 → 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 3, 00Z bilinear tmax+10+50-5-102026-08-04: +0.52 °F2026-08-05: -0.54 °F2026-08-06: +1.41 °F2026-08-07: +0.71 °F2026-08-08: +0.91 °F2026-08-09: +3.46 °F2026-08-10: +7.68 °F2026-08-11: +2.86 °F2026-08-12: -0.13 °F2026-08-13: -0.32 °F2026-08-14: +2.93 °F2026-08-15: -0.23 °F2026-08-16: -0.69 °F2026-08-17: -1.46 °F2026-08-18: -2.04 °F2026-08-19: -0.11 °F2026-08-20: -1.62 °F2026-08-21: -2 °F2026-08-22: -3.25 °F2026-08-23: -1.73 °F2026-08-24: -5.02 °F2026-08-25: -2.6 °F2026-08-26: -2.23 °F2026-08-27: -4.53 °F2026-08-28: +3.32 °F2026-08-29: -0.43 °F2026-08-30: -4.8 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.80
2026-08-29-0.43
2026-08-28+3.32
2026-08-27-4.53
2026-08-26-2.23
2026-08-25-2.60
2026-08-24-5.02
2026-08-23-1.73
2026-08-22-3.25
2026-08-21-2.00
2026-08-20-1.62
2026-08-19-0.11
2026-08-18-2.04
2026-08-17-1.46
2026-08-16-0.69
2026-08-15-0.23
2026-08-14+2.93
2026-08-13-0.32
2026-08-12-0.13
2026-08-11+2.86
2026-08-10+7.68
2026-08-09+3.46
2026-08-08+0.91
2026-08-07+0.71
2026-08-06+1.41
2026-08-05-0.54
2026-08-04+0.52

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KIAH, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 2 days-4 to -3 °F: 1 day-3 to -2 °F: 3 days-2 to -1 °F: 4 days-1 to 0 °F: 7 days0 to 1 °F: 3 days1 to 2 °F: 1 day2 to 3 °F: 2 days3 to 4 °F: 2 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 1.73 · P90 |e| 4.64 °F-100+10 °Fn = 27 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
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.002
-4.00-3.001
-3.00-2.003
-2.00-1.004
-1.00+0.007
+0.00+1.003
+1.00+2.001
+2.00+3.002
+3.00+4.002
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08272.13 -0.37

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27

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 27 -1.53 [-2.63, -0.32] yes
GraphCast (IFS init) 25 -4.40 [-5.86, -2.66] yes
ECMWF IFS HRES 22 -1.33 [-2.48, 0.20] no
Persistence (baseline) 27 -0.24 [-1.18, 0.69] no

Cite this page

ShortCastCheck, KIAH gfs lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/gfs/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model gfs, lead day 3. 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/3/

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