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

Houston Bush · GraphCast (IFS init) · lead day 7

KIAH · graphcast_ifs · lead 7

Target day = initialization date + 7 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
tmax00Zbilinear30d23 1 QC6.13 [4.13, 7.85]2.36-6.11 [-7.85, -4.08]6.70 [4.75, 8.14]4% [0%, 14%]4%17%-0.83+0.292026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC6.13 [3.74, 7.92]2.36-6.11 [-7.92, -3.66]6.70 [4.35, 8.16]4% [0%, 16%]4%17%-0.83+0.292026-08-08 → 2026-08-30
tmax00Zbilinear365d29 1 QC6.23 [4.43, 7.82]2.51-6.13 [-7.75, -4.19]6.86 [4.95, 8.21]3% [0%, 12%]7%17%-0.27+0.512026-01-08 → 2026-08-30
tmax00Zbilinearall29 1 QC6.23 [4.37, 7.87]2.51-6.13 [-7.77, -4.22]6.86 [4.96, 8.23]3% [0%, 12%]7%17%-0.27+0.512026-01-08 → 2026-08-30
tmax00Znearest30d23 1 QC6.34 [4.37, 8.07]2.33-6.34 [-8.07, -4.37]6.90 [4.97, 8.33]4% [0%, 14%]4%17%-0.90+0.302026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC6.34 [3.90, 8.12]2.33-6.34 [-8.12, -3.90]6.90 [4.56, 8.34]4% [0%, 16%]4%17%-0.90+0.302026-08-08 → 2026-08-30
tmax00Znearest365d29 1 QC6.42 [4.65, 8.00]2.49-6.33 [-7.90, -4.44]7.04 [5.19, 8.38]3% [0%, 12%]7%17%-0.31+0.512026-01-08 → 2026-08-30
tmax00Znearestall29 1 QC6.42 [4.60, 8.02]2.49-6.33 [-7.94, -4.49]7.04 [5.15, 8.37]3% [0%, 12%]7%17%-0.31+0.512026-01-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC6.49 [4.64, 8.16]2.08-6.48 [-8.16, -4.60]6.97 [5.11, 8.38]4% [0%, 14%]4%9%-0.94+0.372026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC6.49 [4.33, 8.31]2.08-6.48 [-8.31, -4.29]6.97 [4.81, 8.45]4% [0%, 16%]4%9%-0.94+0.372026-08-08 → 2026-08-30
tmax12Zbilinear365d28 1 QC6.64 [4.84, 8.26]2.42-6.63 [-8.26, -4.82]7.39 [5.26, 8.92]4% [0%, 12%]7%11%-0.60+0.432026-01-08 → 2026-08-30
tmax12Zbilinearall28 1 QC6.64 [4.89, 8.31]2.42-6.63 [-8.31, -4.87]7.39 [5.31, 9.04]4% [0%, 12%]7%11%-0.60+0.432026-01-08 → 2026-08-30
tmax12Znearest30d23 1 QC6.70 [4.90, 8.34]2.04-6.70 [-8.34, -4.90]7.16 [5.34, 8.53]4% [0%, 14%]4%4%-1.00+0.392026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC6.70 [4.56, 8.48]2.04-6.70 [-8.48, -4.56]7.16 [5.06, 8.61]4% [0%, 16%]4%4%-1.00+0.392026-08-08 → 2026-08-30
tmax12Znearest365d28 1 QC6.83 [5.08, 8.42]2.38-6.83 [-8.42, -5.08]7.54 [5.46, 9.03]4% [0%, 12%]7%7%-0.65+0.442026-01-08 → 2026-08-30
tmax12Znearestall28 1 QC6.83 [5.14, 8.47]2.38-6.83 [-8.47, -5.14]7.54 [5.48, 9.12]4% [0%, 12%]7%7%-0.65+0.442026-01-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC2.56 [2.05, 3.04]2.53+1.01 [-0.83, 2.82]3.03 [2.38, 3.55]17% [7%, 32%]39%65%+0.27+0.282026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC2.56 [2.08, 3.09]2.53+1.01 [-0.92, 2.98]3.03 [2.36, 3.64]17% [5%, 33%]39%65%+0.27+0.282026-08-08 → 2026-08-30
tmin00Zbilinear365d29 1 QC2.81 [2.27, 3.37]2.72+0.88 [-0.79, 2.55]3.25 [2.63, 3.77]14% [0%, 26%]34%55%+0.47+0.482026-01-08 → 2026-08-30
tmin00Zbilinearall29 1 QC2.81 [2.23, 3.49]2.72+0.88 [-0.92, 2.45]3.25 [2.59, 3.84]14% [0%, 27%]34%55%+0.47+0.482026-01-08 → 2026-08-30
tmin00Znearest30d23 1 QC2.55 [2.05, 3.01]2.53+0.97 [-0.88, 2.77]3.01 [2.39, 3.52]17% [7%, 32%]35%65%+0.28+0.282026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC2.55 [2.06, 3.07]2.53+0.97 [-0.97, 2.93]3.01 [2.36, 3.60]17% [5%, 33%]35%65%+0.28+0.282026-08-08 → 2026-08-30
tmin00Znearest365d29 1 QC2.81 [2.25, 3.39]2.74+0.86 [-0.80, 2.55]3.24 [2.64, 3.76]14% [0%, 26%]31%55%+0.47+0.482026-01-08 → 2026-08-30
tmin00Znearestall29 1 QC2.81 [2.24, 3.51]2.74+0.86 [-0.95, 2.45]3.24 [2.58, 3.85]14% [0%, 27%]31%55%+0.47+0.482026-01-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC2.64 [2.20, 3.00]2.54+0.76 [-1.17, 2.60]3.05 [2.53, 3.46]17% [7%, 32%]43%61%+0.25+0.282026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC2.64 [2.20, 3.01]2.54+0.76 [-1.23, 2.84]3.05 [2.52, 3.53]17% [5%, 33%]43%61%+0.25+0.282026-08-08 → 2026-08-30
tmin12Zbilinear365d28 1 QC2.72 [2.27, 3.07]2.58+0.83 [-0.96, 2.62]3.12 [2.62, 3.49]18% [8%, 32%]39%57%+0.42+0.462026-01-08 → 2026-08-30
tmin12Zbilinearall28 1 QC2.72 [2.25, 3.10]2.58+0.83 [-1.06, 2.46]3.12 [2.61, 3.51]18% [7%, 33%]39%57%+0.42+0.462026-01-08 → 2026-08-30
tmin12Znearest30d23 1 QC2.63 [2.19, 2.99]2.54+0.72 [-1.19, 2.57]3.03 [2.53, 3.43]17% [7%, 32%]43%61%+0.25+0.282026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC2.63 [2.18, 3.00]2.54+0.72 [-1.27, 2.82]3.03 [2.53, 3.48]17% [5%, 33%]43%61%+0.25+0.282026-08-08 → 2026-08-30
tmin12Znearest365d28 1 QC2.72 [2.26, 3.09]2.59+0.82 [-0.99, 2.62]3.12 [2.62, 3.49]18% [8%, 32%]39%57%+0.42+0.462026-01-08 → 2026-08-30
tmin12Znearestall28 1 QC2.72 [2.25, 3.12]2.59+0.82 [-1.07, 2.45]3.12 [2.62, 3.51]18% [7%, 33%]39%57%+0.42+0.462026-01-08 → 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 7, 00Z bilinear tmax+20+100-10-202026-08-08: -3.5 °F2026-08-09: -7.27 °F2026-08-10: +0.25 °F2026-08-11: -2.58 °F2026-08-12: -5.02 °F2026-08-13: -4.41 °F2026-08-14: -2.4 °F2026-08-15: -6.77 °F2026-08-16: -7.65 °F2026-08-17: -8.05 °F2026-08-18: -9.14 °F2026-08-19: -5.95 °F2026-08-20: -7.8 °F2026-08-21: -8.77 °F2026-08-22: -10.59 °F2026-08-23: -8.57 °F2026-08-24: -10.03 °F2026-08-25: -6.9 °F2026-08-26: -7.58 °F2026-08-27: -7.44 °F2026-08-28: -2.4 °F2026-08-29: -3.52 °F2026-08-30: -4.36 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.36
2026-08-29-3.52
2026-08-28-2.40
2026-08-27-7.44
2026-08-26-7.58
2026-08-25-6.90
2026-08-24-10.03
2026-08-23-8.57
2026-08-22-10.59
2026-08-21-8.77
2026-08-20-7.80
2026-08-19-5.95
2026-08-18-9.14
2026-08-17-8.05
2026-08-16-7.65
2026-08-15-6.77
2026-08-14-2.40
2026-08-13-4.41
2026-08-12-5.02
2026-08-11-2.58
2026-08-10+0.25
2026-08-09-7.27
2026-08-08-3.50

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KIAH, lead day 7-20 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: 4 days-8 to -6 °F: 10 days-6 to -4 °F: 5 days-4 to -2 °F: 5 days-2 to 0 °F: 0 days0 to 2 °F: 2 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| 6.9 · P90 |e| 9.32 °F-200+20 °Fn = 29 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
-10.00-8.004
-8.00-6.0010
-6.00-4.005
-4.00-2.005
-2.00+0.000
+0.00+2.002
+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
2026-08236.13 -6.11
2026-0166.62 -6.20

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 28
GraphCast (IFS init)2026-01-08 → 2026-08-30 28

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 23 +2.96 [1.26, 3.91] yes
NCEP GFS 23 +3.83 [1.06, 5.79] yes
ECMWF IFS HRES 18 +3.12 [0.88, 4.21] yes
Persistence (baseline) 23 +2.78 [-0.35, 4.85] no

Cite this page

ShortCastCheck, KIAH graphcast_ifs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KIAH/model/graphcast_ifs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KIAH (Houston Bush), model graphcast_ifs, lead day 7. 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/7/

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