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

Houston Bush · GraphCast (IFS init) · lead day 2

KIAH · graphcast_ifs · 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, 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
tmax00Zbilinear30d26 1 QC6.37 [5.70, 6.96]1.00-6.37 [-6.96, -5.70]6.52 [5.90, 7.04]0% [0%, 0%]0%4%-2.38+0.482026-08-03 → 2026-08-30
tmax00Zbilinear90d26 1 QC6.37 [5.60, 7.04]1.00-6.37 [-7.04, -5.60]6.52 [5.83, 7.10]0% [0%, 0%]0%4%-2.38+0.482026-08-03 → 2026-08-30
tmax00Zbilinear365d32 1 QC6.51 [5.73, 7.20]1.23-6.51 [-7.20, -5.73]6.74 [5.93, 7.50]0% [0%, 0%]0%3%-1.37+0.562026-01-03 → 2026-08-30
tmax00Zbilinearall32 1 QC6.51 [5.75, 7.15]1.23-6.51 [-7.15, -5.75]6.74 [5.94, 7.45]0% [0%, 0%]0%3%-1.37+0.562026-01-03 → 2026-08-30
tmax00Znearest30d26 1 QC6.61 [5.95, 7.18]1.01-6.61 [-7.18, -5.95]6.74 [6.13, 7.27]0% [0%, 0%]0%0%-2.51+0.482026-08-03 → 2026-08-30
tmax00Znearest90d26 1 QC6.61 [5.86, 7.26]1.01-6.61 [-7.26, -5.86]6.74 [6.06, 7.33]0% [0%, 0%]0%0%-2.51+0.482026-08-03 → 2026-08-30
tmax00Znearest365d32 1 QC6.70 [5.93, 7.33]1.23-6.70 [-7.33, -5.93]6.92 [6.13, 7.62]0% [0%, 0%]0%0%-1.44+0.562026-01-03 → 2026-08-30
tmax00Znearestall32 1 QC6.70 [5.97, 7.31]1.23-6.70 [-7.31, -5.97]6.92 [6.16, 7.59]0% [0%, 0%]0%0%-1.44+0.562026-01-03 → 2026-08-30
tmax12Zbilinear30d26 1 QC7.20 [6.24, 8.14]1.25-7.20 [-8.14, -6.24]7.37 [6.41, 8.20]0% [0%, 0%]0%0%-2.82+0.362026-08-03 → 2026-08-30
tmax12Zbilinear90d26 1 QC7.20 [6.10, 8.24]1.25-7.20 [-8.24, -6.10]7.37 [6.29, 8.32]0% [0%, 0%]0%0%-2.82+0.362026-08-03 → 2026-08-30
tmax12Zbilinear365d31 1 QC7.33 [6.29, 8.26]1.33-7.33 [-8.26, -6.29]7.54 [6.50, 8.39]0% [0%, 0%]0%0%-1.64+0.532026-01-03 → 2026-08-30
tmax12Zbilinearall31 1 QC7.33 [6.31, 8.26]1.33-7.33 [-8.26, -6.31]7.54 [6.52, 8.40]0% [0%, 0%]0%0%-1.64+0.532026-01-03 → 2026-08-30
tmax12Znearest30d26 1 QC7.39 [6.46, 8.30]1.24-7.39 [-8.30, -6.46]7.56 [6.62, 8.38]0% [0%, 0%]0%0%-2.92+0.362026-08-03 → 2026-08-30
tmax12Znearest90d26 1 QC7.39 [6.32, 8.42]1.24-7.39 [-8.42, -6.32]7.56 [6.51, 8.50]0% [0%, 0%]0%0%-2.92+0.362026-08-03 → 2026-08-30
tmax12Znearest365d31 1 QC7.50 [6.49, 8.41]1.34-7.50 [-8.41, -6.49]7.70 [6.69, 8.55]0% [0%, 0%]0%0%-1.70+0.532026-01-03 → 2026-08-30
tmax12Znearestall31 1 QC7.50 [6.50, 8.40]1.34-7.50 [-8.40, -6.50]7.70 [6.70, 8.56]0% [0%, 0%]0%0%-1.70+0.532026-01-03 → 2026-08-30
tmin00Zbilinear30d26 1 QC1.76 [1.33, 2.11]1.68+0.49 [-0.94, 1.61]2.06 [1.54, 2.43]38% [20%, 59%]65%85%+0.23+0.282026-08-03 → 2026-08-30
tmin00Zbilinear90d26 1 QC1.76 [1.20, 2.12]1.68+0.49 [-1.11, 1.75]2.06 [1.34, 2.43]38% [23%, 64%]65%85%+0.23+0.282026-08-03 → 2026-08-30
tmin00Zbilinear365d32 1 QC2.21 [1.53, 3.33]2.14+0.74 [-0.79, 2.25]2.74 [1.77, 3.92]31% [13%, 50%]59%75%+0.53+0.572026-01-03 → 2026-08-30
tmin00Zbilinearall32 1 QC2.21 [1.46, 3.15]2.14+0.74 [-0.80, 2.07]2.74 [1.70, 3.79]31% [15%, 54%]59%75%+0.53+0.572026-01-03 → 2026-08-30
tmin00Znearest30d26 1 QC1.78 [1.37, 2.13]1.72+0.44 [-1.01, 1.60]2.08 [1.57, 2.45]35% [19%, 52%]54%85%+0.21+0.262026-08-03 → 2026-08-30
tmin00Znearest90d26 1 QC1.78 [1.25, 2.13]1.72+0.44 [-1.18, 1.74]2.08 [1.40, 2.46]35% [14%, 57%]54%85%+0.21+0.262026-08-03 → 2026-08-30
tmin00Znearest365d32 1 QC2.24 [1.56, 3.38]2.17+0.71 [-0.86, 2.26]2.77 [1.80, 3.98]28% [8%, 47%]50%75%+0.52+0.562026-01-03 → 2026-08-30
tmin00Znearestall32 1 QC2.24 [1.49, 3.18]2.17+0.71 [-0.85, 2.07]2.77 [1.73, 3.84]28% [11%, 50%]50%75%+0.52+0.562026-01-03 → 2026-08-30
tmin12Zbilinear30d26 1 QC1.87 [1.44, 2.25]1.87-0.05 [-1.64, 1.25]2.23 [1.80, 2.55]35% [20%, 50%]54%85%+0.18+0.202026-08-03 → 2026-08-30
tmin12Zbilinear90d26 1 QC1.87 [1.34, 2.26]1.87-0.05 [-1.85, 1.38]2.23 [1.67, 2.56]35% [19%, 50%]54%85%+0.18+0.202026-08-03 → 2026-08-30
tmin12Zbilinear365d31 1 QC2.25 [1.57, 3.30]2.19+0.43 [-1.43, 2.21]2.82 [1.95, 3.97]29% [12%, 46%]52%77%+0.52+0.552026-01-03 → 2026-08-30
tmin12Zbilinearall31 1 QC2.25 [1.55, 3.16]2.19+0.43 [-1.38, 1.96]2.82 [1.90, 3.87]29% [12%, 48%]52%77%+0.52+0.552026-01-03 → 2026-08-30
tmin12Znearest30d26 1 QC1.88 [1.45, 2.27]1.89-0.06 [-1.68, 1.25]2.23 [1.82, 2.55]38% [28%, 50%]50%85%+0.17+0.192026-08-03 → 2026-08-30
tmin12Znearest90d26 1 QC1.88 [1.36, 2.28]1.89-0.06 [-1.88, 1.39]2.23 [1.69, 2.57]38% [26%, 53%]50%85%+0.17+0.192026-08-03 → 2026-08-30
tmin12Znearest365d31 1 QC2.27 [1.60, 3.34]2.22+0.42 [-1.46, 2.23]2.85 [1.96, 4.04]32% [15%, 47%]45%77%+0.51+0.552026-01-03 → 2026-08-30
tmin12Znearestall31 1 QC2.27 [1.57, 3.20]2.22+0.42 [-1.37, 1.98]2.85 [1.92, 3.93]32% [17%, 48%]45%77%+0.51+0.552026-01-03 → 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 GraphCast (IFS init) at KIAH, lead day 2, 00Z bilinear tmax+10+50-5-102026-08-03: -6.21 °F2026-08-04: -9.22 °F2026-08-05: -5.75 °F2026-08-06: -4.92 °F2026-08-07: -6.93 °F2026-08-08: -5.12 °F2026-08-09: -4.37 °F2026-08-10: -2.65 °F2026-08-11: -5.05 °F2026-08-12: -6.75 °F2026-08-13: -6.28 °F2026-08-14: -5.18 °F2026-08-15: -7.15 °F2026-08-16: -7.37 °F2026-08-17: -7.1 °F2026-08-18: -6.97 °F2026-08-19: -5.34 °F2026-08-20: -6.55 °F2026-08-21: -8.13 °F2026-08-22: -8.61 °F2026-08-23: -6.35 °F2026-08-24: -6.45 °F2026-08-25: -6.22 °F2026-08-26: -6.39 °F2026-08-27: -7.94 °F2026-08-30: -6.67 °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
2026-08-30-6.67
2026-08-29—
2026-08-28—
2026-08-27-7.94
2026-08-26-6.39
2026-08-25-6.22
2026-08-24-6.45
2026-08-23-6.35
2026-08-22-8.61
2026-08-21-8.13
2026-08-20-6.55
2026-08-19-5.34
2026-08-18-6.97
2026-08-17-7.10
2026-08-16-7.37
2026-08-15-7.15
2026-08-14-5.18
2026-08-13-6.28
2026-08-12-6.75
2026-08-11-5.05
2026-08-10-2.65
2026-08-09-4.37
2026-08-08-5.12
2026-08-07-6.93
2026-08-06-4.92
2026-08-05-5.75
2026-08-04-9.22
2026-08-03-6.21

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KIAH, lead day 2-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 3 days-8 to -6 °F: 18 days-6 to -4 °F: 8 days-4 to -2 °F: 2 days-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| 6.5 · P90 |e| 8.11 °F-200+20 °Fn = 32 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
-14.00-12.001
-12.00-10.000
-10.00-8.003
-8.00-6.0018
-6.00-4.008
-4.00-2.002
-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
2026-08266.37 -6.37
2026-0167.10 -7.10

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 31
GraphCast (IFS init)2026-01-03 → 2026-08-30 31

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 26 +2.84 [2.63, 3.16] yes
Aurora (IFS init) 1 +0.08 [0.08, 0.08] yes
FourCastNet v2 (IFS init) 1 +3.60 [3.60, 3.60] yes
NCEP GFS 26 +4.59 [3.59, 5.75] yes
ECMWF IFS HRES 20 +2.96 [2.25, 3.85] yes
Pangu-Weather (IFS init) 1 +2.78 [2.78, 2.78] yes
Persistence (baseline) 26 +4.49 [3.04, 5.89] yes

Cite this page

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

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