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 2

KIAH · gfs · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 1 QC1.74 [1.07, 2.28]1.69-0.48 [-1.89, 0.92]2.38 [1.52, 2.94]39% [18%, 59%]64%82%+0.12+0.142026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC1.74 [0.94, 2.29]1.69-0.48 [-1.97, 1.13]2.38 [1.36, 2.98]39% [18%, 62%]64%82%+0.12+0.142026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC1.74 [0.93, 2.31]1.69-0.48 [-2.08, 1.20]2.38 [1.35, 2.97]39% [17%, 63%]64%82%+0.12+0.142026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC1.74 [0.84, 2.36]1.69-0.48 [-2.12, 1.19]2.38 [1.28, 3.01]39% [14%, 63%]64%82%+0.12+0.142026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC1.75 [1.09, 2.28]1.70-0.52 [-1.79, 0.71]2.40 [1.53, 3.05]32% [14%, 54%]68%79%+0.11+0.142026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC1.75 [1.00, 2.33]1.70-0.52 [-1.85, 0.89]2.40 [1.46, 3.10]32% [14%, 56%]68%79%+0.11+0.142026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC1.75 [0.97, 2.34]1.70-0.52 [-1.95, 0.97]2.40 [1.35, 3.08]32% [12%, 57%]68%79%+0.11+0.142026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC1.75 [0.96, 2.39]1.70-0.52 [-1.97, 0.91]2.40 [1.36, 3.09]32% [11%, 57%]68%79%+0.11+0.142026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC1.53 [1.02, 1.97]1.46-0.34 [-1.62, 1.00]2.03 [1.30, 2.50]39% [23%, 60%]75%82%+0.22+0.262026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC1.53 [0.97, 1.94]1.46-0.34 [-1.74, 1.19]2.03 [1.15, 2.52]39% [22%, 62%]75%82%+0.22+0.262026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC1.53 [0.95, 1.96]1.46-0.34 [-1.80, 1.23]2.03 [1.16, 2.53]39% [21%, 62%]75%82%+0.22+0.262026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC1.53 [0.84, 2.00]1.46-0.34 [-1.88, 1.21]2.03 [1.06, 2.55]39% [21%, 67%]75%82%+0.22+0.262026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC1.55 [1.04, 2.05]1.45-0.40 [-1.70, 0.91]2.07 [1.37, 2.56]39% [23%, 60%]71%82%+0.21+0.262026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC1.55 [1.02, 2.02]1.45-0.40 [-1.84, 1.12]2.07 [1.31, 2.55]39% [22%, 62%]71%82%+0.21+0.262026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC1.55 [1.00, 2.07]1.45-0.40 [-1.92, 1.14]2.07 [1.26, 2.56]39% [21%, 62%]71%82%+0.21+0.262026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC1.55 [0.92, 2.06]1.45-0.40 [-1.95, 1.15]2.07 [1.20, 2.57]39% [21%, 67%]71%82%+0.21+0.262026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC3.45 [2.15, 4.57]1.78+3.45 [2.15, 4.57]4.01 [2.88, 4.78]25% [7%, 47%]29%32%-0.31+0.332026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC3.45 [2.12, 4.73]1.78+3.45 [2.12, 4.73]4.01 [2.80, 4.90]25% [0%, 47%]29%32%-0.31+0.332026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC3.45 [2.01, 4.74]1.78+3.45 [2.01, 4.74]4.01 [2.76, 4.90]25% [0%, 50%]29%32%-0.31+0.332026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC3.45 [1.92, 4.75]1.78+3.45 [1.92, 4.75]4.01 [2.66, 4.90]25% [0%, 50%]29%32%-0.31+0.332026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC3.53 [2.33, 4.57]1.63+3.53 [2.33, 4.57]4.01 [2.97, 4.75]21% [4%, 40%]29%32%-0.33+0.382026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC3.53 [2.32, 4.71]1.63+3.53 [2.32, 4.71]4.01 [2.93, 4.84]21% [0%, 41%]29%32%-0.33+0.382026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC3.53 [2.23, 4.73]1.63+3.53 [2.23, 4.73]4.01 [2.87, 4.86]21% [0%, 43%]29%32%-0.33+0.382026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC3.53 [2.15, 4.74]1.63+3.53 [2.15, 4.74]4.01 [2.76, 4.88]21% [0%, 44%]29%32%-0.33+0.382026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC3.60 [2.36, 4.73]1.90+3.58 [2.34, 4.73]4.29 [3.10, 5.22]21% [4%, 37%]29%36%-0.36+0.282026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC3.60 [2.30, 4.92]1.90+3.58 [2.26, 4.90]4.29 [3.00, 5.31]21% [0%, 38%]29%36%-0.36+0.282026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC3.60 [2.23, 4.89]1.90+3.58 [2.20, 4.89]4.29 [2.96, 5.37]21% [0%, 40%]29%36%-0.36+0.282026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC3.60 [2.14, 4.83]1.90+3.58 [2.09, 4.82]4.29 [2.85, 5.24]21% [0%, 41%]29%36%-0.36+0.282026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC3.77 [2.69, 4.85]1.77+3.76 [2.68, 4.84]4.38 [3.27, 5.30]11% [0%, 21%]25%32%-0.43+0.332026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC3.77 [2.61, 4.95]1.77+3.76 [2.61, 4.94]4.38 [3.16, 5.38]11% [0%, 22%]25%32%-0.43+0.332026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC3.77 [2.53, 4.93]1.77+3.76 [2.53, 4.93]4.38 [3.15, 5.43]11% [0%, 23%]25%32%-0.43+0.332026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC3.77 [2.48, 4.89]1.77+3.76 [2.48, 4.89]4.38 [3.07, 5.31]11% [0%, 22%]25%32%-0.43+0.332026-08-03 → 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 2, 00Z bilinear tmax+10+50-5-102026-08-03: +1.47 °F2026-08-04: -0.21 °F2026-08-05: +0.01 °F2026-08-06: +0.24 °F2026-08-07: -2.46 °F2026-08-08: +0.27 °F2026-08-09: +2.86 °F2026-08-10: +7.2 °F2026-08-11: +1.62 °F2026-08-12: -0.4 °F2026-08-13: +0.38 °F2026-08-14: +3.41 °F2026-08-15: -0.05 °F2026-08-16: -1.42 °F2026-08-17: -0.34 °F2026-08-18: -2.95 °F2026-08-19: -2 °F2026-08-20: -1.2 °F2026-08-21: -1.79 °F2026-08-22: -3.47 °F2026-08-23: -3.4 °F2026-08-24: -4.18 °F2026-08-25: -1.72 °F2026-08-26: -2.73 °F2026-08-27: -0.51 °F2026-08-28: -2.09 °F2026-08-29: +0.17 °F2026-08-30: -0.11 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-0.11
2026-08-29+0.17
2026-08-28-2.09
2026-08-27-0.51
2026-08-26-2.73
2026-08-25-1.72
2026-08-24-4.18
2026-08-23-3.40
2026-08-22-3.47
2026-08-21-1.79
2026-08-20-1.20
2026-08-19-2.00
2026-08-18-2.95
2026-08-17-0.34
2026-08-16-1.42
2026-08-15-0.05
2026-08-14+3.41
2026-08-13+0.38
2026-08-12-0.40
2026-08-11+1.62
2026-08-10+7.20
2026-08-09+2.86
2026-08-08+0.27
2026-08-07-2.46
2026-08-06+0.24
2026-08-05+0.01
2026-08-04-0.21
2026-08-03+1.47

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KIAH, lead day 2-10 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: 0 days-5 to -4 °F: 1 day-4 to -3 °F: 2 days-3 to -2 °F: 4 days-2 to -1 °F: 5 days-1 to 0 °F: 6 days0 to 1 °F: 5 days1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 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| 1.55 · P90 |e| 3.43 °F-100+10 °Fn = 28 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
-6.00-5.000
-5.00-4.001
-4.00-3.002
-3.00-2.004
-2.00-1.005
-1.00+0.006
+0.00+1.005
+1.00+2.002
+2.00+3.001
+3.00+4.001
+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
2026-08281.74 -0.48

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28

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 28 -1.90 [-2.91, -0.78] yes
Aurora (IFS init) 1 -6.49 [-6.49, -6.49] yes
FourCastNet v2 (IFS init) 1 -2.97 [-2.97, -2.97] yes
GraphCast (IFS init) 26 -4.59 [-5.75, -3.59] yes
ECMWF IFS HRES 22 -2.12 [-3.19, -1.06] yes
Pangu-Weather (IFS init) 1 -3.79 [-3.79, -3.79] yes
Persistence (baseline) 28 -0.23 [-1.18, 0.74] no

Cite this page

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

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

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