Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

San Antonio Intl · NCEP GFS · lead day 5

KSAT · gfs · 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, 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
tmax00Zbilinear30d25 1 QC1.90 [1.03, 2.99]1.57-1.61 [-2.90, -0.65]2.74 [1.31, 4.01]36% [16%, 56%]68%84%-0.01+0.192026-08-06 → 2026-08-30
tmax00Zbilinear90d25 1 QC1.90 [0.99, 3.28]1.57-1.61 [-3.22, -0.62]2.74 [1.17, 4.28]36% [13%, 57%]68%84%-0.01+0.192026-08-06 → 2026-08-30
tmax00Zbilinear365d25 1 QC1.90 [0.93, 3.30]1.57-1.61 [-3.26, -0.55]2.74 [1.11, 4.22]36% [14%, 57%]68%84%-0.01+0.192026-08-06 → 2026-08-30
tmax00Zbilinearall25 1 QC1.90 [0.95, 3.21]1.57-1.61 [-3.21, -0.58]2.74 [1.13, 4.18]36% [12%, 57%]68%84%-0.01+0.192026-08-06 → 2026-08-30
tmax00Znearest30d25 1 QC1.80 [0.98, 2.82]1.53-1.37 [-2.66, -0.41]2.55 [1.24, 3.71]40% [20%, 57%]76%84%+0.04+0.212026-08-06 → 2026-08-30
tmax00Znearest90d25 1 QC1.80 [0.94, 3.05]1.53-1.37 [-2.98, -0.37]2.55 [1.08, 3.95]40% [15%, 57%]76%84%+0.04+0.212026-08-06 → 2026-08-30
tmax00Znearest365d25 1 QC1.80 [0.89, 3.07]1.53-1.37 [-3.03, -0.28]2.55 [1.05, 3.90]40% [16%, 58%]76%84%+0.04+0.212026-08-06 → 2026-08-30
tmax00Znearestall25 1 QC1.80 [0.92, 2.99]1.53-1.37 [-2.96, -0.33]2.55 [1.06, 3.90]40% [16%, 58%]76%84%+0.04+0.212026-08-06 → 2026-08-30
tmax12Zbilinear30d25 1 QC1.14 [0.63, 1.79]1.14-0.87 [-1.60, -0.22]1.72 [0.94, 2.47]68% [48%, 87%]76%96%+0.40+0.412026-08-06 → 2026-08-30
tmax12Zbilinear90d25 1 QC1.14 [0.56, 1.95]1.14-0.87 [-1.74, -0.23]1.72 [0.83, 2.60]68% [41%, 88%]76%96%+0.40+0.412026-08-06 → 2026-08-30
tmax12Zbilinear365d25 1 QC1.14 [0.53, 1.99]1.14-0.87 [-1.78, -0.13]1.72 [0.70, 2.60]68% [42%, 90%]76%96%+0.40+0.412026-08-06 → 2026-08-30
tmax12Zbilinearall25 1 QC1.14 [0.56, 1.97]1.14-0.87 [-1.78, -0.19]1.72 [0.86, 2.61]68% [43%, 86%]76%96%+0.40+0.412026-08-06 → 2026-08-30
tmax12Znearest30d25 1 QC1.08 [0.55, 1.77]1.12-0.59 [-1.32, 0.01]1.62 [0.76, 2.42]64% [40%, 87%]80%96%+0.43+0.422026-08-06 → 2026-08-30
tmax12Znearest90d25 1 QC1.08 [0.51, 1.97]1.12-0.59 [-1.45, 0.02]1.62 [0.70, 2.55]64% [33%, 88%]80%96%+0.43+0.422026-08-06 → 2026-08-30
tmax12Znearest365d25 1 QC1.08 [0.46, 2.03]1.12-0.59 [-1.50, 0.09]1.62 [0.61, 2.55]64% [33%, 90%]80%96%+0.43+0.422026-08-06 → 2026-08-30
tmax12Znearestall25 1 QC1.08 [0.53, 1.95]1.12-0.59 [-1.49, 0.05]1.62 [0.66, 2.55]64% [33%, 89%]80%96%+0.43+0.422026-08-06 → 2026-08-30
tmin00Zbilinear30d25 1 QC2.15 [1.78, 2.48]1.68-0.86 [-2.12, 0.45]2.42 [1.97, 2.82]8% [0%, 18%]56%84%-0.54-0.142026-08-06 → 2026-08-30
tmin00Zbilinear90d25 1 QC2.15 [1.71, 2.51]1.68-0.86 [-2.26, 0.70]2.42 [1.87, 2.85]8% [0%, 22%]56%84%-0.54-0.142026-08-06 → 2026-08-30
tmin00Zbilinear365d25 1 QC2.15 [1.70, 2.52]1.68-0.86 [-2.29, 0.81]2.42 [1.82, 2.87]8% [0%, 22%]56%84%-0.54-0.142026-08-06 → 2026-08-30
tmin00Zbilinearall25 1 QC2.15 [1.72, 2.52]1.68-0.86 [-2.26, 0.59]2.42 [1.89, 2.85]8% [0%, 22%]56%84%-0.54-0.142026-08-06 → 2026-08-30
tmin00Znearest30d25 1 QC1.90 [1.45, 2.28]1.67-0.44 [-1.69, 0.86]2.31 [1.70, 2.84]24% [7%, 45%]68%84%-0.35-0.132026-08-06 → 2026-08-30
tmin00Znearest90d25 1 QC1.90 [1.38, 2.34]1.67-0.44 [-1.82, 1.10]2.31 [1.58, 2.92]24% [3%, 46%]68%84%-0.35-0.132026-08-06 → 2026-08-30
tmin00Znearest365d25 1 QC1.90 [1.31, 2.34]1.67-0.44 [-1.87, 1.23]2.31 [1.51, 2.89]24% [0%, 50%]68%84%-0.35-0.132026-08-06 → 2026-08-30
tmin00Znearestall25 1 QC1.90 [1.37, 2.33]1.67-0.44 [-1.84, 1.00]2.31 [1.57, 2.89]24% [4%, 48%]68%84%-0.35-0.132026-08-06 → 2026-08-30
tmin12Zbilinear30d25 1 QC2.06 [1.56, 2.46]1.78-0.69 [-2.02, 0.76]2.46 [1.99, 2.84]28% [10%, 53%]52%76%-0.47-0.202026-08-06 → 2026-08-30
tmin12Zbilinear90d25 1 QC2.06 [1.45, 2.46]1.78-0.69 [-2.11, 1.09]2.46 [1.91, 2.89]28% [9%, 60%]52%76%-0.47-0.202026-08-06 → 2026-08-30
tmin12Zbilinear365d25 1 QC2.06 [1.45, 2.50]1.78-0.69 [-2.19, 1.13]2.46 [1.88, 2.90]28% [10%, 60%]52%76%-0.47-0.202026-08-06 → 2026-08-30
tmin12Zbilinearall25 1 QC2.06 [1.46, 2.46]1.78-0.69 [-2.19, 1.05]2.46 [1.92, 2.86]28% [9%, 63%]52%76%-0.47-0.202026-08-06 → 2026-08-30
tmin12Znearest30d25 1 QC1.87 [1.37, 2.29]1.74-0.30 [-1.62, 1.14]2.37 [1.76, 2.87]36% [20%, 58%]64%80%-0.34-0.182026-08-06 → 2026-08-30
tmin12Znearest90d25 1 QC1.87 [1.28, 2.35]1.74-0.30 [-1.70, 1.44]2.37 [1.63, 3.02]36% [21%, 62%]64%80%-0.34-0.182026-08-06 → 2026-08-30
tmin12Znearest365d25 1 QC1.87 [1.26, 2.42]1.74-0.30 [-1.79, 1.52]2.37 [1.59, 3.02]36% [20%, 62%]64%80%-0.34-0.182026-08-06 → 2026-08-30
tmin12Znearestall25 1 QC1.87 [1.32, 2.34]1.74-0.30 [-1.76, 1.40]2.37 [1.67, 2.96]36% [21%, 67%]64%80%-0.34-0.182026-08-06 → 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 NCEP GFS at KSAT, lead day 5, 00Z bilinear tmax+10+50-5-102026-08-06: -3.94 °F2026-08-07: -2.45 °F2026-08-08: -2.18 °F2026-08-09: -4.94 °F2026-08-10: +1.1 °F2026-08-11: -0.56 °F2026-08-12: +0.59 °F2026-08-13: -1.88 °F2026-08-14: +1.14 °F2026-08-15: -1.58 °F2026-08-16: -0.24 °F2026-08-17: +0.65 °F2026-08-18: +0.08 °F2026-08-19: -0.23 °F2026-08-20: -2 °F2026-08-21: -0.72 °F2026-08-22: -1.37 °F2026-08-23: -1.46 °F2026-08-24: -1.06 °F2026-08-25: -1.4 °F2026-08-26: -0.2 °F2026-08-27: -4.54 °F2026-08-28: -9.23 °F2026-08-29: -2.93 °F2026-08-30: -0.95 °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
2026-08-30-0.95
2026-08-29-2.93
2026-08-28-9.23
2026-08-27-4.54
2026-08-26-0.20
2026-08-25-1.40
2026-08-24-1.06
2026-08-23-1.46
2026-08-22-1.37
2026-08-21-0.72
2026-08-20-2.00
2026-08-19-0.23
2026-08-18+0.08
2026-08-17+0.65
2026-08-16-0.24
2026-08-15-1.58
2026-08-14+1.14
2026-08-13-1.88
2026-08-12+0.59
2026-08-11-0.56
2026-08-10+1.10
2026-08-09-4.94
2026-08-08-2.18
2026-08-07-2.45
2026-08-06-3.94

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KSAT, lead day 5-10 to -9 °F: 1 day-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 2 days-4 to -3 °F: 1 day-3 to -2 °F: 4 days-2 to -1 °F: 6 days-1 to 0 °F: 6 days0 to 1 °F: 3 days1 to 2 °F: 2 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 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| 1.37 · P90 |e| 4.3 °F-100+10 °Fn = 25 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
-10.00-9.001
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.000
-5.00-4.002
-4.00-3.001
-3.00-2.004
-2.00-1.006
-1.00+0.006
+0.00+1.003
+1.00+2.002
+2.00+3.000
+3.00+4.000
+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
2026-08251.90 -1.61

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25

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 25 -0.88 [-2.00, 1.14] no
GraphCast (IFS init) 25 -3.60 [-5.81, -0.46] yes
ECMWF IFS HRES 18 -0.78 [-2.42, 1.70] no
Persistence (baseline) 25 +0.02 [-1.05, 1.56] no

Cite this page

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

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