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

San Antonio Intl · GraphCast (IFS init) · lead day 7

KSAT · 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 QC5.60 [3.61, 7.18]1.99-5.60 [-7.18, -3.61]6.13 [4.08, 7.55]4% [0%, 17%]4%13%-1.74+0.012026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC5.60 [3.18, 7.33]1.99-5.60 [-7.33, -3.18]6.13 [3.65, 7.72]4% [0%, 22%]4%13%-1.74+0.012026-08-08 → 2026-08-30
tmax00Zbilinear365d29 1 QC5.53 [3.92, 7.00]1.90-5.53 [-7.00, -3.92]6.03 [4.34, 7.37]3% [0%, 14%]7%14%-0.32+0.612026-01-08 → 2026-08-30
tmax00Zbilinearall29 1 QC5.53 [3.96, 7.06]1.90-5.53 [-7.06, -3.96]6.03 [4.41, 7.41]3% [0%, 13%]7%14%-0.32+0.612026-01-08 → 2026-08-30
tmax00Znearest30d23 1 QC5.30 [3.30, 6.90]2.01-5.29 [-6.90, -3.27]5.87 [3.82, 7.32]4% [0%, 17%]9%26%-1.59+0.012026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC5.30 [2.87, 7.05]2.01-5.29 [-7.05, -2.83]5.87 [3.37, 7.47]4% [0%, 22%]9%26%-1.59+0.012026-08-08 → 2026-08-30
tmax00Znearest365d29 1 QC5.26 [3.64, 6.74]1.91-5.26 [-6.74, -3.62]5.79 [4.10, 7.11]3% [0%, 14%]10%24%-0.25+0.612026-01-08 → 2026-08-30
tmax00Znearestall29 1 QC5.26 [3.73, 6.82]1.91-5.26 [-6.82, -3.71]5.79 [4.13, 7.17]3% [0%, 13%]10%24%-0.25+0.612026-01-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC5.85 [4.05, 7.29]1.89-5.85 [-7.29, -4.05]6.29 [4.26, 7.69]0% [0%, 0%]0%9%-1.86+0.072026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC5.85 [3.71, 7.47]1.89-5.85 [-7.47, -3.71]6.29 [3.90, 7.80]0% [0%, 0%]0%9%-1.86+0.072026-08-08 → 2026-08-30
tmax12Zbilinear365d28 1 QC5.52 [3.82, 6.98]2.23-5.49 [-6.98, -3.74]6.17 [4.44, 7.50]7% [0%, 24%]7%14%-0.53+0.452026-01-08 → 2026-08-30
tmax12Zbilinearall28 1 QC5.52 [3.84, 7.04]2.23-5.49 [-7.02, -3.75]6.17 [4.56, 7.61]7% [0%, 26%]7%14%-0.53+0.452026-01-08 → 2026-08-30
tmax12Znearest30d23 1 QC5.56 [3.73, 7.02]1.92-5.56 [-7.02, -3.73]6.04 [3.98, 7.45]0% [0%, 0%]0%22%-1.72+0.052026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC5.56 [3.37, 7.20]1.92-5.56 [-7.20, -3.37]6.04 [3.59, 7.56]0% [0%, 0%]0%22%-1.72+0.052026-08-08 → 2026-08-30
tmax12Znearest365d28 1 QC5.24 [3.51, 6.74]2.23-5.21 [-6.71, -3.46]5.93 [4.17, 7.26]7% [0%, 24%]7%29%-0.45+0.452026-01-08 → 2026-08-30
tmax12Znearestall28 1 QC5.24 [3.52, 6.79]2.23-5.21 [-6.75, -3.47]5.93 [4.31, 7.39]7% [0%, 26%]7%29%-0.45+0.452026-01-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC1.58 [0.86, 2.47]1.29+1.29 [0.41, 2.22]2.34 [1.07, 3.57]48% [33%, 64%]74%96%+0.12+0.272026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC1.58 [0.83, 2.73]1.29+1.29 [0.38, 2.43]2.34 [1.04, 3.88]48% [30%, 67%]74%96%+0.12+0.272026-08-08 → 2026-08-30
tmin00Zbilinear365d29 1 QC2.13 [1.09, 3.53]1.82+1.07 [-0.34, 2.28]2.94 [1.35, 4.30]38% [14%, 57%]59%83%+0.40+0.472026-01-08 → 2026-08-30
tmin00Zbilinearall29 1 QC2.13 [1.14, 3.74]1.82+1.07 [-0.30, 2.24]2.94 [1.44, 4.28]38% [11%, 59%]59%83%+0.40+0.472026-01-08 → 2026-08-30
tmin00Znearest30d23 1 QC1.72 [0.97, 2.61]1.28+1.51 [0.64, 2.43]2.47 [1.19, 3.70]39% [27%, 55%]65%96%+0.04+0.272026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC1.72 [0.95, 2.86]1.28+1.51 [0.60, 2.65]2.47 [1.17, 4.01]39% [25%, 56%]65%96%+0.04+0.272026-08-08 → 2026-08-30
tmin00Znearest365d29 1 QC2.25 [1.23, 3.60]1.81+1.26 [-0.18, 2.47]3.03 [1.49, 4.34]31% [12%, 50%]52%83%+0.37+0.482026-01-08 → 2026-08-30
tmin00Znearestall29 1 QC2.25 [1.26, 3.78]1.81+1.26 [-0.12, 2.44]3.03 [1.58, 4.36]31% [10%, 48%]52%83%+0.37+0.482026-01-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC1.37 [0.70, 2.35]1.35+0.94 [0.08, 1.88]2.14 [0.91, 3.36]52% [22%, 85%]74%96%+0.23+0.232026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC1.37 [0.66, 2.73]1.35+0.94 [0.06, 2.16]2.14 [0.85, 3.72]52% [17%, 88%]74%96%+0.23+0.232026-08-08 → 2026-08-30
tmin12Zbilinear365d28 1 QC1.82 [0.79, 3.28]1.75+1.44 [0.28, 2.98]2.67 [1.05, 3.97]46% [17%, 79%]64%82%+0.46+0.462026-01-08 → 2026-08-30
tmin12Zbilinearall28 1 QC1.82 [0.78, 3.44]1.75+1.44 [0.24, 3.21]2.67 [1.06, 4.11]46% [15%, 79%]64%82%+0.46+0.462026-01-08 → 2026-08-30
tmin12Znearest30d23 1 QC1.45 [0.69, 2.46]1.34+1.15 [0.30, 2.08]2.24 [0.96, 3.47]48% [22%, 75%]74%96%+0.19+0.242026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC1.45 [0.66, 2.81]1.34+1.15 [0.29, 2.37]2.24 [0.92, 3.82]48% [17%, 76%]74%96%+0.19+0.242026-08-08 → 2026-08-30
tmin12Znearest365d28 1 QC1.90 [0.81, 3.39]1.74+1.63 [0.49, 3.15]2.76 [1.14, 4.09]43% [17%, 71%]64%82%+0.43+0.462026-01-08 → 2026-08-30
tmin12Znearestall28 1 QC1.90 [0.80, 3.56]1.74+1.63 [0.47, 3.34]2.76 [1.15, 4.22]43% [15%, 71%]64%82%+0.43+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 KSAT, lead day 7, 00Z bilinear tmax+20+100-10-202026-08-08: -0.26 °F2026-08-09: -6.31 °F2026-08-10: -2.15 °F2026-08-11: -3.31 °F2026-08-12: -3.45 °F2026-08-13: -5.16 °F2026-08-14: -4.74 °F2026-08-15: -6.87 °F2026-08-16: -5.57 °F2026-08-17: -6.01 °F2026-08-18: -7.7 °F2026-08-19: -6.95 °F2026-08-20: -6.49 °F2026-08-21: -6.42 °F2026-08-22: -9.58 °F2026-08-23: -10.74 °F2026-08-24: -9.5 °F2026-08-25: -7.98 °F2026-08-26: -5.29 °F2026-08-27: -4.63 °F2026-08-28: -3.15 °F2026-08-29: -3.63 °F2026-08-30: -2.99 °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
2026-08-30-2.99
2026-08-29-3.63
2026-08-28-3.15
2026-08-27-4.63
2026-08-26-5.29
2026-08-25-7.98
2026-08-24-9.50
2026-08-23-10.74
2026-08-22-9.58
2026-08-21-6.42
2026-08-20-6.49
2026-08-19-6.95
2026-08-18-7.70
2026-08-17-6.01
2026-08-16-5.57
2026-08-15-6.87
2026-08-14-4.74
2026-08-13-5.16
2026-08-12-3.45
2026-08-11-3.31
2026-08-10-2.15
2026-08-09-6.31
2026-08-08-0.26

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KSAT, 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: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 2 days-8 to -6 °F: 11 days-6 to -4 °F: 7 days-4 to -2 °F: 6 days-2 to 0 °F: 2 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| 5.57 · P90 |e| 8.28 °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
-14.00-12.000
-12.00-10.001
-10.00-8.002
-8.00-6.0011
-6.00-4.007
-4.00-2.006
-2.00+0.002
+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
2026-08235.60 -5.60
2026-0165.26 -5.26

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 +2.83 [0.60, 4.03] yes
NCEP GFS 23 +3.57 [0.53, 5.27] yes
ECMWF IFS HRES 18 +3.13 [0.12, 4.34] yes
Persistence (baseline) 23 +3.56 [0.40, 5.45] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAT (San Antonio Intl), 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/KSAT/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