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

Houston Bush · GraphCast (IFS init) · lead day 0

KIAH · graphcast_ifs · lead 0

Target day = initialization date + 0 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, 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
tmax00Zbilinear30d28 1 QC5.55 [5.34, 5.75]0.83-5.55 [-5.75, -5.34]5.67 [5.45, 5.89]0% [0%, 0%]0%4%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d28 1 QC5.55 [5.31, 5.77]0.83-5.55 [-5.77, -5.31]5.67 [5.44, 5.89]0% [0%, 0%]0%4%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d34 1 QC5.79 [5.42, 6.36]1.03-5.79 [-6.36, -5.42]5.96 [5.53, 6.62]0% [0%, 0%]0%3%——2026-01-01 → 2026-08-30
tmax00Zbilinearall34 1 QC5.79 [5.42, 6.29]1.03-5.79 [-6.29, -5.42]5.96 [5.54, 6.54]0% [0%, 0%]0%3%——2026-01-01 → 2026-08-30
tmax00Znearest30d28 1 QC5.89 [5.68, 6.10]0.77-5.89 [-6.10, -5.68]6.00 [5.80, 6.20]0% [0%, 0%]0%4%——2026-08-01 → 2026-08-30
tmax00Znearest90d28 1 QC5.89 [5.66, 6.10]0.77-5.89 [-6.10, -5.66]6.00 [5.78, 6.21]0% [0%, 0%]0%4%——2026-08-01 → 2026-08-30
tmax00Znearest365d34 1 QC6.10 [5.77, 6.57]0.98-6.10 [-6.57, -5.77]6.25 [5.87, 6.83]0% [0%, 0%]0%3%——2026-01-01 → 2026-08-30
tmax00Znearestall34 1 QC6.10 [5.76, 6.52]0.98-6.10 [-6.52, -5.76]6.25 [5.89, 6.77]0% [0%, 0%]0%3%——2026-01-01 → 2026-08-30
tmin00Zbilinear30d28 1 QC1.80 [1.45, 2.16]1.49+1.06 [0.21, 1.80]2.17 [1.76, 2.54]32% [20%, 48%]64%79%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d28 1 QC1.80 [1.44, 2.16]1.49+1.06 [0.07, 1.81]2.17 [1.73, 2.55]32% [19%, 50%]64%79%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d34 1 QC2.30 [1.53, 3.49]1.99+1.56 [0.38, 2.82]2.98 [1.88, 4.34]29% [16%, 44%]59%71%——2026-01-01 → 2026-08-30
tmin00Zbilinearall34 1 QC2.30 [1.57, 3.25]1.99+1.56 [0.48, 2.62]2.98 [1.94, 4.09]29% [17%, 46%]59%71%——2026-01-01 → 2026-08-30
tmin00Znearest30d28 1 QC1.71 [1.43, 2.04]1.52+0.84 [-0.08, 1.63]2.08 [1.72, 2.45]32% [23%, 42%]64%86%——2026-08-01 → 2026-08-30
tmin00Znearest90d28 1 QC1.71 [1.42, 2.03]1.52+0.84 [-0.24, 1.66]2.08 [1.69, 2.45]32% [24%, 43%]64%86%——2026-08-01 → 2026-08-30
tmin00Znearest365d34 1 QC2.23 [1.51, 3.44]2.01+1.34 [0.08, 2.62]2.90 [1.84, 4.25]26% [14%, 39%]59%76%——2026-01-01 → 2026-08-30
tmin00Znearestall34 1 QC2.23 [1.51, 3.19]2.01+1.34 [0.19, 2.44]2.90 [1.85, 4.02]26% [14%, 40%]59%76%——2026-01-01 → 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 0, 00Z bilinear tmax+10+50-5-102026-08-01: -2.27 °F2026-08-02: -8.95 °F2026-08-03: -5.22 °F2026-08-04: -4.82 °F2026-08-05: -6.1 °F2026-08-06: -4.7 °F2026-08-07: -5.68 °F2026-08-08: -5.38 °F2026-08-09: -5.35 °F2026-08-10: -4.27 °F2026-08-11: -6.71 °F2026-08-12: -5.96 °F2026-08-13: -5.18 °F2026-08-14: -5.72 °F2026-08-15: -5.18 °F2026-08-16: -6.96 °F2026-08-17: -5.88 °F2026-08-18: -5.18 °F2026-08-19: -3.51 °F2026-08-20: -5.66 °F2026-08-21: -6.62 °F2026-08-22: -6.03 °F2026-08-23: -4.46 °F2026-08-24: -6.66 °F2026-08-25: -5.36 °F2026-08-28: -6.16 °F2026-08-29: -6.14 °F2026-08-30: -5.13 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.13
2026-08-29-6.14
2026-08-28-6.16
2026-08-27—
2026-08-26—
2026-08-25-5.36
2026-08-24-6.66
2026-08-23-4.46
2026-08-22-6.03
2026-08-21-6.62
2026-08-20-5.66
2026-08-19-3.51
2026-08-18-5.18
2026-08-17-5.88
2026-08-16-6.96
2026-08-15-5.18
2026-08-14-5.72
2026-08-13-5.18
2026-08-12-5.96
2026-08-11-6.71
2026-08-10-4.27
2026-08-09-5.35
2026-08-08-5.38
2026-08-07-5.68
2026-08-06-4.70
2026-08-05-6.10
2026-08-04-4.82
2026-08-03-5.22
2026-08-02-8.95
2026-08-01-2.27

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KIAH, lead day 0-10 to -9 °F: 1 day-9 to -8 °F: 2 days-8 to -7 °F: 1 day-7 to -6 °F: 9 days-6 to -5 °F: 14 days-5 to -4 °F: 4 days-4 to -3 °F: 2 days-3 to -2 °F: 1 day-2 to -1 °F: 0 days-1 to 0 °F: 0 days0 to 1 °F: 0 days1 to 2 °F: 0 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 5.7 · P90 |e| 7.67 °F-100+10 °Fn = 34 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
-9.00-8.002
-8.00-7.001
-7.00-6.009
-6.00-5.0014
-5.00-4.004
-4.00-3.002
-3.00-2.001
-2.00-1.000
-1.00+0.000
+0.00+1.000
+1.00+2.000
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+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
2026-08285.55 -5.55
2026-0166.90 -6.90

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-01 → 2026-08-30 34
GraphCast (IFS init)2026-01-01 → 2026-08-30 34

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 28 +2.30 [1.72, 2.96] yes
Aurora (GFS init) 2 +0.28 [-0.43, 1.00] no
Aurora (IFS init) 3 -0.52 [-1.03, -0.26] yes
FourCastNet v2 (GFS init) 2 +1.76 [1.42, 2.09] yes
FourCastNet v2 (IFS init) 3 +1.33 [1.25, 1.50] yes
NCEP GFS 28 +4.31 [3.89, 4.68] yes
GraphCast (GFS init) 2 +1.55 [1.36, 1.73] yes
ECMWF IFS HRES 22 +1.69 [0.85, 2.22] yes
Pangu-Weather (GFS init) 2 +3.13 [2.45, 3.82] yes
Pangu-Weather (IFS init) 3 +2.51 [2.25, 2.64] yes

Cite this page

ShortCastCheck, KIAH graphcast_ifs lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/graphcast_ifs/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model graphcast_ifs, lead day 0. 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/0/

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

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