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

San Antonio Intl · NCEP GFS · lead day 7

KSAT · gfs · 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, gfs-0p25, starting 2026-08-01 — 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 QC2.04 [1.46, 2.74]1.70-1.22 [-1.89, -0.53]2.55 [1.67, 3.24]22% [4%, 37%]61%78%+0.00+0.162026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC2.04 [1.34, 2.87]1.70-1.22 [-1.87, -0.42]2.55 [1.54, 3.31]22% [0%, 38%]61%78%+0.00+0.162026-08-08 → 2026-08-30
tmax00Zbilinear365d23 1 QC2.04 [1.30, 2.80]1.70-1.22 [-1.99, -0.43]2.55 [1.51, 3.32]22% [0%, 39%]61%78%+0.00+0.162026-08-08 → 2026-08-30
tmax00Zbilinearall23 1 QC2.04 [1.30, 2.86]1.70-1.22 [-1.96, -0.41]2.55 [1.50, 3.37]22% [0%, 38%]61%78%+0.00+0.162026-08-08 → 2026-08-30
tmax00Znearest30d23 1 QC1.91 [1.30, 2.64]1.69-1.00 [-1.67, -0.30]2.47 [1.54, 3.21]26% [15%, 37%]61%78%+0.07+0.162026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC1.91 [1.19, 2.77]1.69-1.00 [-1.65, -0.21]2.47 [1.38, 3.29]26% [14%, 36%]61%78%+0.07+0.162026-08-08 → 2026-08-30
tmax00Znearest365d23 1 QC1.91 [1.13, 2.73]1.69-1.00 [-1.76, -0.22]2.47 [1.34, 3.35]26% [12%, 37%]61%78%+0.07+0.162026-08-08 → 2026-08-30
tmax00Znearestall23 1 QC1.91 [1.14, 2.78]1.69-1.00 [-1.74, -0.19]2.47 [1.35, 3.34]26% [13%, 36%]61%78%+0.07+0.162026-08-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC1.98 [1.43, 2.62]1.86-0.76 [-1.70, 0.74]2.50 [1.92, 2.99]30% [12%, 45%]52%78%+0.03+0.082026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC1.98 [1.43, 2.64]1.86-0.76 [-1.72, 1.33]2.50 [1.94, 3.00]30% [13%, 44%]52%78%+0.03+0.082026-08-08 → 2026-08-30
tmax12Zbilinear365d23 1 QC1.98 [1.39, 2.68]1.86-0.76 [-1.85, 1.32]2.50 [1.87, 3.06]30% [11%, 45%]52%78%+0.03+0.082026-08-08 → 2026-08-30
tmax12Zbilinearall23 1 QC1.98 [1.42, 2.86]1.86-0.76 [-1.77, 1.64]2.50 [1.94, 3.16]30% [0%, 45%]52%78%+0.03+0.082026-08-08 → 2026-08-30
tmax12Znearest30d23 1 QC1.84 [1.31, 2.42]1.80-0.45 [-1.32, 0.99]2.36 [1.82, 2.82]39% [17%, 60%]65%83%+0.10+0.112026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC1.84 [1.31, 2.45]1.80-0.45 [-1.37, 1.57]2.36 [1.84, 2.82]39% [14%, 61%]65%83%+0.10+0.112026-08-08 → 2026-08-30
tmax12Znearest365d23 1 QC1.84 [1.26, 2.50]1.80-0.45 [-1.48, 1.54]2.36 [1.72, 2.86]39% [14%, 62%]65%83%+0.10+0.112026-08-08 → 2026-08-30
tmax12Znearestall23 1 QC1.84 [1.28, 2.63]1.80-0.45 [-1.41, 1.86]2.36 [1.82, 2.93]39% [9%, 62%]65%83%+0.10+0.112026-08-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC2.04 [1.54, 2.52]1.59-1.22 [-2.20, -0.22]2.31 [1.75, 2.74]17% [4%, 32%]43%78%-0.15+0.102026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC2.04 [1.46, 2.53]1.59-1.22 [-2.26, -0.05]2.31 [1.68, 2.74]17% [0%, 36%]43%78%-0.15+0.102026-08-08 → 2026-08-30
tmin00Zbilinear365d23 1 QC2.04 [1.45, 2.56]1.59-1.22 [-2.30, -0.09]2.31 [1.67, 2.79]17% [0%, 36%]43%78%-0.15+0.102026-08-08 → 2026-08-30
tmin00Zbilinearall23 1 QC2.04 [1.42, 2.59]1.59-1.22 [-2.31, 0.03]2.31 [1.62, 2.78]17% [0%, 36%]43%78%-0.15+0.102026-08-08 → 2026-08-30
tmin00Znearest30d23 1 QC1.86 [1.37, 2.36]1.59-0.80 [-1.79, 0.22]2.14 [1.58, 2.61]17% [5%, 33%]61%87%-0.05+0.092026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC1.86 [1.27, 2.41]1.59-0.80 [-1.87, 0.41]2.14 [1.48, 2.67]17% [4%, 38%]61%87%-0.05+0.092026-08-08 → 2026-08-30
tmin00Znearest365d23 1 QC1.86 [1.25, 2.49]1.59-0.80 [-1.92, 0.36]2.14 [1.48, 2.71]17% [0%, 39%]61%87%-0.05+0.092026-08-08 → 2026-08-30
tmin00Znearestall23 1 QC1.86 [1.26, 2.52]1.59-0.80 [-1.92, 0.47]2.14 [1.48, 2.68]17% [0%, 37%]61%87%-0.05+0.092026-08-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC2.13 [1.76, 2.49]1.82-0.67 [-2.00, 0.78]2.42 [2.00, 2.84]26% [13%, 44%]48%83%-0.20-0.032026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC2.13 [1.64, 2.53]1.82-0.67 [-2.01, 0.96]2.42 [1.87, 2.87]26% [12%, 50%]48%83%-0.20-0.032026-08-08 → 2026-08-30
tmin12Zbilinear365d23 1 QC2.13 [1.65, 2.56]1.82-0.67 [-2.08, 1.05]2.42 [1.88, 2.89]26% [12%, 50%]48%83%-0.20-0.032026-08-08 → 2026-08-30
tmin12Zbilinearall23 1 QC2.13 [1.63, 2.55]1.82-0.67 [-2.07, 0.98]2.42 [1.87, 2.87]26% [13%, 50%]48%83%-0.20-0.032026-08-08 → 2026-08-30
tmin12Znearest30d23 1 QC1.93 [1.44, 2.48]1.81-0.27 [-1.59, 1.16]2.31 [1.70, 2.91]26% [13%, 44%]57%87%-0.08-0.032026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC1.93 [1.32, 2.53]1.81-0.27 [-1.61, 1.34]2.31 [1.61, 2.97]26% [12%, 50%]57%87%-0.08-0.032026-08-08 → 2026-08-30
tmin12Znearest365d23 1 QC1.93 [1.35, 2.58]1.81-0.27 [-1.67, 1.42]2.31 [1.59, 2.97]26% [12%, 50%]57%87%-0.08-0.032026-08-08 → 2026-08-30
tmin12Znearestall23 1 QC1.93 [1.31, 2.57]1.81-0.27 [-1.66, 1.36]2.31 [1.60, 2.99]26% [13%, 50%]57%87%-0.08-0.032026-08-08 → 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 NCEP GFS at KSAT, lead day 7, 00Z bilinear tmax+10+50-5-102026-08-08: +3.18 °F2026-08-09: -5.55 °F2026-08-10: -1.31 °F2026-08-11: -3.22 °F2026-08-12: -1.97 °F2026-08-13: -1.14 °F2026-08-14: +1.54 °F2026-08-15: -2.51 °F2026-08-16: +1.15 °F2026-08-17: -1.32 °F2026-08-18: -0.13 °F2026-08-19: +0.93 °F2026-08-20: -2.85 °F2026-08-21: -2.22 °F2026-08-22: -5.72 °F2026-08-23: -4.38 °F2026-08-24: -0.46 °F2026-08-25: +0.01 °F2026-08-26: +2.58 °F2026-08-27: -1.31 °F2026-08-28: -0.3 °F2026-08-29: -1.89 °F2026-08-30: -1.23 °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
2026-08-30-1.23
2026-08-29-1.89
2026-08-28-0.30
2026-08-27-1.31
2026-08-26+2.58
2026-08-25+0.01
2026-08-24-0.46
2026-08-23-4.38
2026-08-22-5.72
2026-08-21-2.22
2026-08-20-2.85
2026-08-19+0.93
2026-08-18-0.13
2026-08-17-1.32
2026-08-16+1.15
2026-08-15-2.51
2026-08-14+1.54
2026-08-13-1.14
2026-08-12-1.97
2026-08-11-3.22
2026-08-10-1.31
2026-08-09-5.55
2026-08-08+3.18

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KSAT, lead day 7-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 2 days-5 to -4 °F: 1 day-4 to -3 °F: 1 day-3 to -2 °F: 3 days-2 to -1 °F: 7 days-1 to 0 °F: 3 days0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 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| 1.54 · P90 |e| 4.14 °F-100+10 °Fn = 23 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
-10.00-9.000
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.001
-4.00-3.001
-3.00-2.003
-2.00-1.007
-1.00+0.003
+0.00+1.002
+1.00+2.002
+2.00+3.001
+3.00+4.001
+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
2026-08232.04 -1.22

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means NCEP GFS has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 23 -0.74 [-1.25, 0.25] no
GraphCast (IFS init) 23 -3.57 [-5.27, -0.53] yes
ECMWF IFS HRES 18 -1.02 [-1.95, 0.57] no
Persistence (baseline) 23 -0.00 [-1.32, 0.96] no

Cite this page

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

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