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

Houston Bush · GraphCast (IFS init) · lead day 5

KIAH · graphcast_ifs · lead 5

Target day = initialization date + 5 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
tmax00Zbilinear30d25 1 QC6.23 [4.98, 7.69]1.83-6.23 [-7.69, -4.98]6.60 [5.25, 7.88]0% [0%, 0%]0%4%-1.10+0.382026-08-06 → 2026-08-30
tmax00Zbilinear90d25 1 QC6.23 [4.81, 7.74]1.83-6.23 [-7.74, -4.81]6.60 [5.03, 7.98]0% [0%, 0%]0%4%-1.10+0.382026-08-06 → 2026-08-30
tmax00Zbilinear365d31 1 QC6.70 [5.32, 8.31]2.08-6.70 [-8.31, -5.32]7.15 [5.62, 8.65]0% [0%, 0%]0%3%-0.59+0.512026-01-06 → 2026-08-30
tmax00Zbilinearall31 1 QC6.70 [5.34, 8.42]2.08-6.70 [-8.42, -5.34]7.15 [5.71, 8.67]0% [0%, 0%]0%3%-0.59+0.512026-01-06 → 2026-08-30
tmax00Znearest30d25 1 QC6.43 [5.23, 7.83]1.78-6.43 [-7.83, -5.23]6.78 [5.47, 8.02]0% [0%, 0%]0%0%-1.17+0.402026-08-06 → 2026-08-30
tmax00Znearest90d25 1 QC6.43 [5.06, 7.89]1.78-6.43 [-7.89, -5.06]6.78 [5.26, 8.12]0% [0%, 0%]0%0%-1.17+0.402026-08-06 → 2026-08-30
tmax00Znearest365d31 1 QC6.86 [5.55, 8.37]2.00-6.86 [-8.37, -5.55]7.27 [5.84, 8.68]0% [0%, 0%]0%0%-0.62+0.532026-01-06 → 2026-08-30
tmax00Znearestall31 1 QC6.86 [5.58, 8.49]2.00-6.86 [-8.49, -5.58]7.27 [5.94, 8.72]0% [0%, 0%]0%0%-0.62+0.532026-01-06 → 2026-08-30
tmax12Zbilinear30d25 1 QC6.69 [5.31, 8.13]1.84-6.69 [-8.13, -5.31]7.05 [5.69, 8.34]0% [0%, 0%]4%4%-1.26+0.372026-08-06 → 2026-08-30
tmax12Zbilinear90d25 1 QC6.69 [5.11, 8.16]1.84-6.69 [-8.16, -5.11]7.05 [5.47, 8.34]0% [0%, 0%]4%4%-1.26+0.372026-08-06 → 2026-08-30
tmax12Zbilinear365d30 1 QC6.83 [5.42, 8.23]1.89-6.83 [-8.23, -5.42]7.19 [5.73, 8.43]0% [0%, 0%]3%3%-0.78+0.502026-01-06 → 2026-08-30
tmax12Zbilinearall30 1 QC6.83 [5.43, 8.22]1.89-6.83 [-8.22, -5.43]7.19 [5.80, 8.44]0% [0%, 0%]3%3%-0.78+0.502026-01-06 → 2026-08-30
tmax12Znearest30d25 1 QC6.90 [5.58, 8.31]1.82-6.90 [-8.31, -5.58]7.24 [5.94, 8.50]0% [0%, 0%]0%4%-1.33+0.382026-08-06 → 2026-08-30
tmax12Znearest90d25 1 QC6.90 [5.38, 8.38]1.82-6.90 [-8.38, -5.38]7.24 [5.72, 8.51]0% [0%, 0%]0%4%-1.33+0.382026-08-06 → 2026-08-30
tmax12Znearest365d30 1 QC7.00 [5.66, 8.37]1.87-7.00 [-8.37, -5.66]7.34 [5.98, 8.57]0% [0%, 0%]0%3%-0.83+0.512026-01-06 → 2026-08-30
tmax12Znearestall30 1 QC7.00 [5.64, 8.38]1.87-7.00 [-8.38, -5.64]7.34 [6.00, 8.57]0% [0%, 0%]0%3%-0.83+0.512026-01-06 → 2026-08-30
tmin00Zbilinear30d25 1 QC2.39 [2.00, 2.72]2.25+0.71 [-1.01, 2.17]2.71 [2.27, 3.07]12% [3%, 23%]44%72%+0.15+0.192026-08-06 → 2026-08-30
tmin00Zbilinear90d25 1 QC2.39 [1.93, 2.72]2.25+0.71 [-1.06, 2.38]2.71 [2.19, 3.08]12% [0%, 25%]44%72%+0.15+0.192026-08-06 → 2026-08-30
tmin00Zbilinear365d31 1 QC2.53 [2.12, 3.01]2.48+0.51 [-1.19, 2.27]3.01 [2.42, 3.71]16% [4%, 29%]42%65%+0.51+0.552026-01-06 → 2026-08-30
tmin00Zbilinearall31 1 QC2.53 [2.15, 3.08]2.48+0.51 [-1.26, 2.17]3.01 [2.48, 3.81]16% [4%, 31%]42%65%+0.51+0.552026-01-06 → 2026-08-30
tmin00Znearest30d25 1 QC2.38 [1.98, 2.71]2.25+0.66 [-1.06, 2.15]2.70 [2.27, 3.04]12% [3%, 23%]44%72%+0.15+0.192026-08-06 → 2026-08-30
tmin00Znearest90d25 1 QC2.38 [1.92, 2.72]2.25+0.66 [-1.10, 2.36]2.70 [2.18, 3.03]12% [0%, 25%]44%72%+0.15+0.192026-08-06 → 2026-08-30
tmin00Znearest365d31 1 QC2.53 [2.12, 3.03]2.46+0.49 [-1.20, 2.23]3.01 [2.42, 3.73]16% [4%, 29%]42%65%+0.51+0.552026-01-06 → 2026-08-30
tmin00Znearestall31 1 QC2.53 [2.14, 3.11]2.46+0.49 [-1.24, 2.14]3.01 [2.47, 3.83]16% [4%, 31%]42%65%+0.51+0.552026-01-06 → 2026-08-30
tmin12Zbilinear30d25 1 QC2.07 [1.64, 2.40]2.02+0.35 [-1.19, 1.79]2.38 [1.89, 2.72]20% [4%, 40%]52%80%+0.26+0.282026-08-06 → 2026-08-30
tmin12Zbilinear90d25 1 QC2.07 [1.52, 2.40]2.02+0.35 [-1.24, 1.94]2.38 [1.77, 2.73]20% [0%, 43%]52%80%+0.26+0.282026-08-06 → 2026-08-30
tmin12Zbilinear365d30 1 QC2.30 [1.76, 2.92]2.30-0.02 [-1.66, 1.76]2.65 [2.02, 3.26]17% [0%, 35%]47%73%+0.49+0.542026-01-06 → 2026-08-30
tmin12Zbilinearall30 1 QC2.30 [1.74, 2.96]2.30-0.02 [-1.81, 1.57]2.65 [2.04, 3.28]17% [0%, 36%]47%73%+0.49+0.542026-01-06 → 2026-08-30
tmin12Znearest30d25 1 QC2.08 [1.64, 2.42]2.04+0.32 [-1.23, 1.77]2.38 [1.90, 2.72]24% [5%, 47%]44%80%+0.26+0.272026-08-06 → 2026-08-30
tmin12Znearest90d25 1 QC2.08 [1.53, 2.43]2.04+0.32 [-1.28, 1.91]2.38 [1.78, 2.73]24% [0%, 50%]44%80%+0.26+0.272026-08-06 → 2026-08-30
tmin12Znearest365d30 1 QC2.31 [1.77, 2.94]2.31-0.03 [-1.65, 1.74]2.65 [2.03, 3.24]20% [0%, 43%]40%73%+0.49+0.542026-01-06 → 2026-08-30
tmin12Znearestall30 1 QC2.31 [1.77, 2.99]2.31-0.03 [-1.80, 1.57]2.65 [2.06, 3.27]20% [0%, 43%]40%73%+0.49+0.542026-01-06 → 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 5, 00Z bilinear tmax+20+100-10-202026-08-06: -5.62 °F2026-08-07: -8.49 °F2026-08-08: -4.76 °F2026-08-09: -4.16 °F2026-08-10: -2.58 °F2026-08-11: -4.35 °F2026-08-12: -5.49 °F2026-08-13: -4.51 °F2026-08-14: -3.14 °F2026-08-15: -7 °F2026-08-16: -7.79 °F2026-08-17: -7.57 °F2026-08-18: -7.29 °F2026-08-19: -6.43 °F2026-08-20: -8.13 °F2026-08-21: -9.68 °F2026-08-22: -10.47 °F2026-08-23: -7.07 °F2026-08-24: -10.32 °F2026-08-25: -7.31 °F2026-08-26: -6.25 °F2026-08-27: -3.87 °F2026-08-28: -3.07 °F2026-08-29: -4.32 °F2026-08-30: -5.98 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.98
2026-08-29-4.32
2026-08-28-3.07
2026-08-27-3.87
2026-08-26-6.25
2026-08-25-7.31
2026-08-24-10.32
2026-08-23-7.07
2026-08-22-10.47
2026-08-21-9.68
2026-08-20-8.13
2026-08-19-6.43
2026-08-18-7.29
2026-08-17-7.57
2026-08-16-7.79
2026-08-15-7.00
2026-08-14-3.14
2026-08-13-4.51
2026-08-12-5.49
2026-08-11-4.35
2026-08-10-2.58
2026-08-09-4.16
2026-08-08-4.76
2026-08-07-8.49
2026-08-06-5.62

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KIAH, lead day 5-20 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: 2 days-10 to -8 °F: 6 days-8 to -6 °F: 9 days-6 to -4 °F: 8 days-4 to -2 °F: 5 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| 7 · P90 |e| 9.78 °F-200+20 °Fn = 31 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
-12.00-10.002
-10.00-8.006
-8.00-6.009
-6.00-4.008
-4.00-2.005
-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
2026-08256.23 -6.23
2026-0168.70 -8.70

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 30
GraphCast (IFS init)2026-01-06 → 2026-08-30 30

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 25 +2.95 [2.18, 3.72] yes
NCEP GFS 25 +3.93 [1.18, 6.19] yes
ECMWF IFS HRES 18 +2.56 [0.69, 4.20] yes
Persistence (baseline) 25 +3.27 [1.04, 5.38] yes

Cite this page

ShortCastCheck, KIAH graphcast_ifs lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/graphcast_ifs/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model graphcast_ifs, lead day 5. 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/5/

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