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 6

KIAH · 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, 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
tmax00Zbilinear30d24 1 QC2.64 [1.46, 3.75]2.45-1.01 [-3.44, 1.47]3.62 [2.20, 4.70]33% [6%, 63%]50%67%+0.18+0.232026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC2.64 [1.34, 3.98]2.45-1.01 [-3.85, 1.80]3.62 [2.02, 4.92]33% [0%, 67%]50%67%+0.18+0.232026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC2.64 [1.23, 4.04]2.45-1.01 [-4.00, 1.99]3.62 [1.70, 4.86]33% [0%, 71%]50%67%+0.18+0.232026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC2.64 [1.19, 3.95]2.45-1.01 [-3.82, 1.97]3.62 [1.62, 4.84]33% [0%, 67%]50%67%+0.18+0.232026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC2.63 [1.43, 3.73]2.51-0.91 [-3.44, 1.69]3.58 [2.21, 4.57]42% [16%, 69%]50%62%+0.18+0.212026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC2.63 [1.30, 3.90]2.51-0.91 [-3.80, 2.08]3.58 [2.00, 4.65]42% [15%, 73%]50%62%+0.18+0.212026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC2.63 [1.18, 4.01]2.51-0.91 [-3.99, 2.24]3.58 [1.73, 4.66]42% [14%, 77%]50%62%+0.18+0.212026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC2.63 [1.15, 3.90]2.51-0.91 [-3.87, 2.11]3.58 [1.61, 4.67]42% [14%, 73%]50%62%+0.18+0.212026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC1.92 [1.16, 2.67]1.77-1.21 [-2.50, 0.10]2.58 [1.68, 3.32]46% [26%, 70%]62%71%+0.40+0.452026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC1.92 [1.09, 2.74]1.77-1.21 [-2.52, 0.21]2.58 [1.58, 3.32]46% [23%, 70%]62%71%+0.40+0.452026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC1.92 [1.05, 2.76]1.77-1.21 [-2.74, 0.26]2.58 [1.50, 3.40]46% [22%, 73%]62%71%+0.40+0.452026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC1.92 [1.05, 2.85]1.77-1.21 [-2.76, 0.26]2.58 [1.47, 3.47]46% [20%, 74%]62%71%+0.40+0.452026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC2.30 [1.37, 3.12]2.15-1.50 [-2.73, -0.06]3.02 [1.97, 3.70]33% [12%, 56%]54%58%+0.28+0.332026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC2.30 [1.26, 3.31]2.15-1.50 [-3.12, 0.05]3.02 [1.79, 3.80]33% [9%, 56%]54%58%+0.28+0.332026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC2.30 [1.17, 3.34]2.15-1.50 [-3.16, 0.19]3.02 [1.67, 3.83]33% [9%, 57%]54%58%+0.28+0.332026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC2.30 [1.25, 3.43]2.15-1.50 [-3.18, 0.20]3.02 [1.77, 3.84]33% [7%, 57%]54%58%+0.28+0.332026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC3.47 [2.19, 4.71]2.29+3.19 [1.72, 4.69]4.16 [2.94, 5.03]25% [6%, 43%]38%42%-0.28+0.162026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC3.47 [2.18, 4.89]2.29+3.19 [1.68, 4.89]4.16 [2.94, 5.14]25% [0%, 43%]38%42%-0.28+0.162026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC3.47 [2.00, 4.84]2.29+3.19 [1.44, 4.84]4.16 [2.66, 5.11]25% [0%, 46%]38%42%-0.28+0.162026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC3.47 [1.79, 4.83]2.29+3.19 [1.25, 4.82]4.16 [2.26, 5.14]25% [0%, 47%]38%42%-0.28+0.162026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC3.53 [2.39, 4.62]2.31+3.22 [1.86, 4.60]4.22 [3.07, 4.99]21% [9%, 31%]33%42%-0.30+0.152026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC3.53 [2.40, 4.75]2.31+3.22 [1.86, 4.75]4.22 [3.12, 5.09]21% [6%, 31%]33%42%-0.30+0.152026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC3.53 [2.20, 4.75]2.31+3.22 [1.65, 4.75]4.22 [2.84, 5.05]21% [7%, 32%]33%42%-0.30+0.152026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC3.53 [2.03, 4.76]2.31+3.22 [1.46, 4.74]4.22 [2.45, 5.11]21% [5%, 32%]33%42%-0.30+0.152026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC3.64 [2.56, 4.64]2.36+3.20 [1.59, 4.60]4.26 [3.24, 4.98]21% [7%, 33%]29%38%-0.34+0.132026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC3.64 [2.52, 4.74]2.36+3.20 [1.61, 4.74]4.26 [3.20, 5.06]21% [0%, 33%]29%38%-0.34+0.132026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC3.64 [2.36, 4.78]2.36+3.20 [1.31, 4.78]4.26 [3.09, 5.10]21% [0%, 33%]29%38%-0.34+0.132026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC3.64 [2.29, 4.77]2.36+3.20 [1.18, 4.77]4.26 [2.89, 5.07]21% [0%, 33%]29%38%-0.34+0.132026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC3.69 [2.71, 4.59]2.36+3.24 [1.72, 4.55]4.32 [3.37, 5.04]21% [7%, 33%]25%38%-0.36+0.132026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC3.69 [2.71, 4.69]2.36+3.24 [1.74, 4.66]4.32 [3.39, 5.02]21% [0%, 33%]25%38%-0.36+0.132026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC3.69 [2.54, 4.74]2.36+3.24 [1.45, 4.72]4.32 [3.24, 5.10]21% [0%, 33%]25%38%-0.36+0.132026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC3.69 [2.43, 4.69]2.36+3.24 [1.34, 4.67]4.32 [3.13, 5.09]21% [0%, 33%]25%38%-0.36+0.132026-08-07 → 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 KIAH, lead day 6, 00Z bilinear tmax+10+50-5-102026-08-07: +0.19 °F2026-08-08: -1.3 °F2026-08-09: +3.37 °F2026-08-10: +8.09 °F2026-08-11: +2.3 °F2026-08-12: +0.2 °F2026-08-13: +1.22 °F2026-08-14: +3.6 °F2026-08-15: -0.66 °F2026-08-16: -0.61 °F2026-08-17: -0.8 °F2026-08-18: -0.33 °F2026-08-19: +0.55 °F2026-08-20: -0.85 °F2026-08-21: -2.81 °F2026-08-22: -7 °F2026-08-23: -1.82 °F2026-08-24: -2.76 °F2026-08-25: -2.09 °F2026-08-26: -4.04 °F2026-08-27: -3.97 °F2026-08-28: -9.6 °F2026-08-29: -4.1 °F2026-08-30: -1.06 °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
2026-08-30-1.06
2026-08-29-4.10
2026-08-28-9.60
2026-08-27-3.97
2026-08-26-4.04
2026-08-25-2.09
2026-08-24-2.76
2026-08-23-1.82
2026-08-22-7.00
2026-08-21-2.81
2026-08-20-0.85
2026-08-19+0.55
2026-08-18-0.33
2026-08-17-0.80
2026-08-16-0.61
2026-08-15-0.66
2026-08-14+3.60
2026-08-13+1.22
2026-08-12+0.20
2026-08-11+2.30
2026-08-10+8.09
2026-08-09+3.37
2026-08-08-1.30
2026-08-07+0.19

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KIAH, lead day 6-10 to -9 °F: 1 day-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 2 days-4 to -3 °F: 1 day-3 to -2 °F: 3 days-2 to -1 °F: 3 days-1 to 0 °F: 5 days0 to 1 °F: 3 days1 to 2 °F: 1 day2 to 3 °F: 1 day3 to 4 °F: 2 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 1 day9 to 10 °F: 0 daysdashed: P50 |e| 1.95 · P90 |e| 6.13 °F-100+10 °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
-10.00-9.001
-9.00-8.000
-8.00-7.001
-7.00-6.000
-6.00-5.000
-5.00-4.002
-4.00-3.001
-3.00-2.003
-2.00-1.003
-1.00+0.005
+0.00+1.003
+1.00+2.001
+2.00+3.001
+3.00+4.002
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.001
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08242.64 -1.01

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 -0.61 [-2.24, 1.59] no
GraphCast (IFS init) 24 -3.65 [-6.20, -0.94] yes
ECMWF IFS HRES 19 -1.26 [-2.74, 0.06] no
Persistence (baseline) 24 -0.57 [-1.99, 0.94] no

Cite this page

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

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