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CastCheck methodology v0.2 · data through 2026-08-30

Houston Bush · GraphCast (IFS init) · lead day 1

KIAH · graphcast_ifs · lead 1

Target day = initialization date + 1 day. 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, GRAP_v100, starting 2026-01-01 — 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 QC6.20 [5.88, 6.53]0.85-6.20 [-6.53, -5.88]6.29 [5.94, 6.65]0% [0%, 0%]0%0%-3.19+0.452026-08-02 → 2026-08-30
tmax00Zbilinear90d27 1 QC6.20 [5.87, 6.62]0.85-6.20 [-6.62, -5.87]6.29 [5.93, 6.72]0% [0%, 0%]0%0%-3.19+0.452026-08-02 → 2026-08-30
tmax00Zbilinear365d33 1 QC6.48 [5.98, 7.26]1.10-6.48 [-7.26, -5.98]6.66 [6.06, 7.52]0% [0%, 0%]0%0%-1.64+0.572026-01-02 → 2026-08-30
tmax00Zbilinearall33 1 QC6.48 [5.97, 7.18]1.10-6.48 [-7.18, -5.97]6.66 [6.05, 7.48]0% [0%, 0%]0%0%-1.64+0.572026-01-02 → 2026-08-30
tmax00Znearest30d27 1 QC6.44 [6.12, 6.77]0.85-6.44 [-6.77, -6.12]6.53 [6.18, 6.87]0% [0%, 0%]0%0%-3.35+0.442026-08-02 → 2026-08-30
tmax00Znearest90d27 1 QC6.44 [6.10, 6.84]0.85-6.44 [-6.84, -6.10]6.53 [6.16, 6.93]0% [0%, 0%]0%0%-3.35+0.442026-08-02 → 2026-08-30
tmax00Znearest365d33 1 QC6.67 [6.20, 7.34]1.08-6.67 [-7.34, -6.20]6.85 [6.27, 7.61]0% [0%, 0%]0%0%-1.72+0.582026-01-02 → 2026-08-30
tmax00Znearestall33 1 QC6.67 [6.20, 7.34]1.08-6.67 [-7.34, -6.20]6.85 [6.27, 7.62]0% [0%, 0%]0%0%-1.72+0.582026-01-02 → 2026-08-30
tmax12Zbilinear30d27 1 QC7.26 [6.64, 7.95]1.01-7.26 [-7.95, -6.64]7.37 [6.70, 8.05]0% [0%, 0%]0%0%-3.90+0.342026-08-02 → 2026-08-30
tmax12Zbilinear90d27 1 QC7.26 [6.58, 8.04]1.01-7.26 [-8.04, -6.58]7.37 [6.64, 8.14]0% [0%, 0%]0%0%-3.90+0.342026-08-02 → 2026-08-30
tmax12Zbilinear365d32 1 QC7.39 [6.74, 8.11]1.14-7.39 [-8.11, -6.74]7.51 [6.81, 8.23]0% [0%, 0%]0%0%-1.95+0.562026-01-02 → 2026-08-30
tmax12Zbilinearall32 1 QC7.39 [6.70, 8.12]1.14-7.39 [-8.12, -6.70]7.51 [6.79, 8.25]0% [0%, 0%]0%0%-1.95+0.562026-01-02 → 2026-08-30
tmax12Znearest30d27 1 QC7.48 [6.90, 8.14]0.96-7.48 [-8.14, -6.90]7.57 [6.95, 8.23]0% [0%, 0%]0%0%-4.05+0.372026-08-02 → 2026-08-30
tmax12Znearest90d27 1 QC7.48 [6.83, 8.22]0.96-7.48 [-8.22, -6.83]7.57 [6.88, 8.31]0% [0%, 0%]0%0%-4.05+0.372026-08-02 → 2026-08-30
tmax12Znearest365d32 1 QC7.58 [6.95, 8.27]1.09-7.58 [-8.27, -6.95]7.70 [7.03, 8.39]0% [0%, 0%]0%0%-2.03+0.582026-01-02 → 2026-08-30
tmax12Znearestall32 1 QC7.58 [6.93, 8.27]1.09-7.58 [-8.27, -6.93]7.70 [7.01, 8.41]0% [0%, 0%]0%0%-2.03+0.582026-01-02 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.78 [1.39, 2.15]1.64+0.73 [-0.51, 1.78]2.14 [1.70, 2.54]30% [17%, 44%]59%81%+0.04+0.122026-08-02 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.78 [1.25, 2.18]1.64+0.73 [-0.66, 1.84]2.14 [1.58, 2.55]30% [13%, 48%]59%81%+0.04+0.122026-08-02 → 2026-08-30
tmin00Zbilinear365d33 1 QC2.23 [1.46, 3.29]2.12+1.00 [-0.39, 2.20]2.85 [1.79, 4.07]24% [9%, 40%]55%73%+0.38+0.412026-01-02 → 2026-08-30
tmin00Zbilinearall33 1 QC2.23 [1.42, 3.17]2.12+1.00 [-0.40, 2.01]2.85 [1.76, 3.96]24% [8%, 42%]55%73%+0.38+0.412026-01-02 → 2026-08-30
tmin00Znearest30d27 1 QC1.78 [1.42, 2.14]1.67+0.66 [-0.64, 1.75]2.15 [1.74, 2.55]30% [17%, 44%]67%81%+0.04+0.102026-08-02 → 2026-08-30
tmin00Znearest90d27 1 QC1.78 [1.30, 2.18]1.67+0.66 [-0.77, 1.82]2.15 [1.63, 2.56]30% [13%, 48%]67%81%+0.04+0.102026-08-02 → 2026-08-30
tmin00Znearest365d33 1 QC2.24 [1.49, 3.31]2.15+0.94 [-0.50, 2.18]2.88 [1.80, 4.10]24% [9%, 40%]58%73%+0.37+0.402026-01-02 → 2026-08-30
tmin00Znearestall33 1 QC2.24 [1.45, 3.20]2.15+0.94 [-0.51, 2.00]2.88 [1.79, 3.99]24% [8%, 42%]58%73%+0.37+0.402026-01-02 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.84 [1.50, 2.18]1.84+0.06 [-1.36, 1.28]2.27 [1.93, 2.59]37% [24%, 50%]59%78%+0.01+0.012026-08-02 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.84 [1.31, 2.32]1.84+0.06 [-1.52, 1.42]2.27 [1.71, 2.73]37% [20%, 56%]59%78%+0.01+0.012026-08-02 → 2026-08-30
tmin12Zbilinear365d32 1 QC2.34 [1.55, 3.62]2.33+0.45 [-1.20, 1.97]2.97 [1.99, 4.26]31% [13%, 50%]50%69%+0.36+0.372026-01-02 → 2026-08-30
tmin12Zbilinearall32 1 QC2.34 [1.52, 3.48]2.33+0.45 [-1.20, 1.76]2.97 [1.98, 4.12]31% [12%, 50%]50%69%+0.36+0.372026-01-02 → 2026-08-30
tmin12Znearest30d27 1 QC1.85 [1.48, 2.19]1.85+0.01 [-1.43, 1.24]2.29 [1.93, 2.62]37% [24%, 50%]56%78%-0.00+0.002026-08-02 → 2026-08-30
tmin12Znearest90d27 1 QC1.85 [1.28, 2.36]1.85+0.01 [-1.59, 1.38]2.29 [1.72, 2.75]37% [20%, 56%]56%78%-0.00+0.002026-08-02 → 2026-08-30
tmin12Znearest365d32 1 QC2.37 [1.56, 3.67]2.35+0.41 [-1.25, 1.97]3.01 [2.00, 4.33]31% [13%, 50%]47%69%+0.35+0.372026-01-02 → 2026-08-30
tmin12Znearestall32 1 QC2.37 [1.51, 3.55]2.35+0.41 [-1.22, 1.75]3.01 [1.98, 4.19]31% [12%, 50%]47%69%+0.35+0.372026-01-02 → 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 GraphCast (IFS init) at KIAH, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -6.52 °F2026-08-03: -8.2 °F2026-08-04: -6.31 °F2026-08-05: -5.23 °F2026-08-06: -5.63 °F2026-08-07: -6.96 °F2026-08-08: -5.42 °F2026-08-09: -5.05 °F2026-08-10: -5.82 °F2026-08-11: -4.56 °F2026-08-12: -7.03 °F2026-08-13: -5.54 °F2026-08-14: -5.7 °F2026-08-15: -5.93 °F2026-08-16: -7.19 °F2026-08-17: -6.66 °F2026-08-18: -6.31 °F2026-08-19: -4.12 °F2026-08-20: -6.29 °F2026-08-21: -7.83 °F2026-08-22: -8.73 °F2026-08-23: -4.37 °F2026-08-24: -6.65 °F2026-08-25: -6.39 °F2026-08-26: -6.34 °F2026-08-29: -5.63 °F2026-08-30: -7.03 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-7.03
2026-08-29-5.63
2026-08-28—
2026-08-27—
2026-08-26-6.34
2026-08-25-6.39
2026-08-24-6.65
2026-08-23-4.37
2026-08-22-8.73
2026-08-21-7.83
2026-08-20-6.29
2026-08-19-4.12
2026-08-18-6.31
2026-08-17-6.66
2026-08-16-7.19
2026-08-15-5.93
2026-08-14-5.70
2026-08-13-5.54
2026-08-12-7.03
2026-08-11-4.56
2026-08-10-5.82
2026-08-09-5.05
2026-08-08-5.42
2026-08-07-6.96
2026-08-06-5.63
2026-08-05-5.23
2026-08-04-6.31
2026-08-03-8.20
2026-08-02-6.52

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KIAH, lead day 1-20 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: 4 days-8 to -6 °F: 15 days-6 to -4 °F: 12 days-4 to -2 °F: 1 day-2 to 0 °F: 0 days0 to 2 °F: 0 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 6.34 · P90 |e| 8.2 °F-200+20 °Fn = 33 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
-10.00-8.004
-8.00-6.0015
-6.00-4.0012
-4.00-2.001
-2.00+0.000
+0.00+2.000
+2.00+4.000
+4.00+6.000
+6.00+8.000
+8.00+10.000
+10.00+12.000
+12.00+14.000
+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
2026-08276.20 -6.20
2026-0167.71 -7.71

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 32
GraphCast (IFS init)2026-01-02 → 2026-08-30 32

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means GraphCast (IFS init) has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 27 +2.63 [2.20, 3.19] yes
Aurora (GFS init) 1 +0.65 [0.65, 0.65] yes
Aurora (IFS init) 2 +0.08 [-0.07, 0.22] no
FourCastNet v2 (GFS init) 1 +3.64 [3.64, 3.64] yes
FourCastNet v2 (IFS init) 2 +2.63 [1.77, 3.48] yes
NCEP GFS 27 +4.96 [4.48, 5.73] yes
GraphCast (GFS init) 1 +1.48 [1.48, 1.48] yes
ECMWF IFS HRES 21 +2.60 [2.09, 3.15] yes
Pangu-Weather (GFS init) 1 +4.89 [4.89, 4.89] yes
Pangu-Weather (IFS init) 2 +2.77 [1.93, 3.60] yes
Persistence (baseline) 27 +4.72 [3.85, 5.59] yes

Cite this page

ShortCastCheck, KIAH graphcast_ifs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/graphcast_ifs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model graphcast_ifs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KIAH/model/graphcast_ifs/lead/1/

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

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