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

San Antonio Intl · ECMWF AIFS Single · lead day 4

KSAT · aifs_single · lead 4

Target day = initialization date + 4 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, aifs-single-gpid5, 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
tmax00Zbilinear30d26 1 QC2.82 [2.39, 3.12]0.83-2.82 [-3.12, -2.39]3.00 [2.63, 3.22]4% [0%, 14%]31%46%-0.60+0.542026-08-05 → 2026-08-30
tmax00Zbilinear90d26 1 QC2.82 [2.28, 3.15]0.83-2.82 [-3.15, -2.28]3.00 [2.56, 3.25]4% [0%, 17%]31%46%-0.60+0.542026-08-05 → 2026-08-30
tmax00Zbilinear365d26 1 QC2.82 [2.24, 3.17]0.83-2.82 [-3.17, -2.24]3.00 [2.53, 3.26]4% [0%, 18%]31%46%-0.60+0.542026-08-05 → 2026-08-30
tmax00Zbilinearall26 1 QC2.82 [2.19, 3.16]0.83-2.82 [-3.16, -2.19]3.00 [2.51, 3.26]4% [0%, 20%]31%46%-0.60+0.542026-08-05 → 2026-08-30
tmax00Znearest30d26 1 QC2.40 [1.96, 2.70]0.85-2.40 [-2.70, -1.96]2.61 [2.25, 2.83]15% [3%, 35%]31%73%-0.36+0.532026-08-05 → 2026-08-30
tmax00Znearest90d26 1 QC2.40 [1.84, 2.73]0.85-2.40 [-2.73, -1.84]2.61 [2.20, 2.84]15% [0%, 39%]31%73%-0.36+0.532026-08-05 → 2026-08-30
tmax00Znearest365d26 1 QC2.40 [1.80, 2.74]0.85-2.40 [-2.74, -1.80]2.61 [2.21, 2.87]15% [0%, 43%]31%73%-0.36+0.532026-08-05 → 2026-08-30
tmax00Znearestall26 1 QC2.40 [1.75, 2.75]0.85-2.40 [-2.75, -1.75]2.61 [2.15, 2.86]15% [0%, 41%]31%73%-0.36+0.532026-08-05 → 2026-08-30
tmax12Zbilinear30d26 1 QC3.42 [2.91, 3.73]1.01-3.42 [-3.73, -2.91]3.64 [3.19, 3.92]4% [0%, 14%]15%42%-0.93+0.442026-08-05 → 2026-08-30
tmax12Zbilinear90d26 1 QC3.42 [2.84, 3.75]1.01-3.42 [-3.75, -2.84]3.64 [3.10, 3.93]4% [0%, 17%]15%42%-0.93+0.442026-08-05 → 2026-08-30
tmax12Zbilinear365d26 1 QC3.42 [2.84, 3.77]1.01-3.42 [-3.77, -2.84]3.64 [3.10, 3.95]4% [0%, 18%]15%42%-0.93+0.442026-08-05 → 2026-08-30
tmax12Zbilinearall26 1 QC3.42 [2.76, 3.78]1.01-3.42 [-3.78, -2.76]3.64 [3.03, 3.94]4% [0%, 20%]15%42%-0.93+0.442026-08-05 → 2026-08-30
tmax12Znearest30d26 1 QC2.99 [2.47, 3.32]1.03-2.99 [-3.32, -2.47]3.25 [2.80, 3.54]4% [0%, 14%]19%50%-0.69+0.422026-08-05 → 2026-08-30
tmax12Znearest90d26 1 QC2.99 [2.40, 3.33]1.03-2.99 [-3.33, -2.40]3.25 [2.72, 3.54]4% [0%, 17%]19%50%-0.69+0.422026-08-05 → 2026-08-30
tmax12Znearest365d26 1 QC2.99 [2.41, 3.34]1.03-2.99 [-3.34, -2.41]3.25 [2.67, 3.57]4% [0%, 18%]19%50%-0.69+0.422026-08-05 → 2026-08-30
tmax12Znearestall26 1 QC2.99 [2.29, 3.36]1.03-2.99 [-3.36, -2.29]3.25 [2.61, 3.55]4% [0%, 20%]19%50%-0.69+0.422026-08-05 → 2026-08-30
tmin00Zbilinear30d26 1 QC1.52 [1.24, 1.81]1.40-0.59 [-1.50, 0.44]1.83 [1.51, 2.16]35% [22%, 46%]73%92%-0.10+0.032026-08-05 → 2026-08-30
tmin00Zbilinear90d26 1 QC1.52 [1.20, 1.85]1.40-0.59 [-1.55, 0.56]1.83 [1.44, 2.20]35% [20%, 46%]73%92%-0.10+0.032026-08-05 → 2026-08-30
tmin00Zbilinear365d26 1 QC1.52 [1.19, 1.84]1.40-0.59 [-1.57, 0.63]1.83 [1.43, 2.17]35% [21%, 47%]73%92%-0.10+0.032026-08-05 → 2026-08-30
tmin00Zbilinearall26 1 QC1.52 [1.15, 1.85]1.40-0.59 [-1.59, 0.59]1.83 [1.38, 2.21]35% [19%, 46%]73%92%-0.10+0.032026-08-05 → 2026-08-30
tmin00Znearest30d26 1 QC1.47 [1.18, 1.81]1.41-0.35 [-1.28, 0.69]1.79 [1.43, 2.15]38% [24%, 52%]69%92%-0.06+0.022026-08-05 → 2026-08-30
tmin00Znearest90d26 1 QC1.47 [1.11, 1.86]1.41-0.35 [-1.33, 0.82]1.79 [1.33, 2.23]38% [22%, 53%]69%92%-0.06+0.022026-08-05 → 2026-08-30
tmin00Znearest365d26 1 QC1.47 [1.13, 1.89]1.41-0.35 [-1.35, 0.88]1.79 [1.36, 2.26]38% [19%, 53%]69%92%-0.06+0.022026-08-05 → 2026-08-30
tmin00Znearestall26 1 QC1.47 [1.13, 1.86]1.41-0.35 [-1.37, 0.84]1.79 [1.35, 2.23]38% [20%, 53%]69%92%-0.06+0.022026-08-05 → 2026-08-30
tmin12Zbilinear30d26 1 QC1.69 [1.32, 2.04]1.42-0.90 [-1.83, 0.17]2.02 [1.60, 2.37]35% [18%, 52%]69%81%-0.22+0.012026-08-05 → 2026-08-30
tmin12Zbilinear90d26 1 QC1.69 [1.29, 2.05]1.42-0.90 [-1.88, 0.35]2.02 [1.54, 2.39]35% [16%, 54%]69%81%-0.22+0.012026-08-05 → 2026-08-30
tmin12Zbilinear365d26 1 QC1.69 [1.24, 2.07]1.42-0.90 [-1.90, 0.40]2.02 [1.52, 2.40]35% [15%, 56%]69%81%-0.22+0.012026-08-05 → 2026-08-30
tmin12Zbilinearall26 1 QC1.69 [1.19, 2.05]1.42-0.90 [-1.92, 0.32]2.02 [1.39, 2.41]35% [14%, 57%]69%81%-0.22+0.012026-08-05 → 2026-08-30
tmin12Znearest30d26 1 QC1.61 [1.31, 1.92]1.43-0.66 [-1.61, 0.42]1.94 [1.55, 2.32]35% [24%, 46%]73%92%-0.16+0.002026-08-05 → 2026-08-30
tmin12Znearest90d26 1 QC1.61 [1.24, 1.95]1.43-0.66 [-1.66, 0.60]1.94 [1.48, 2.35]35% [23%, 44%]73%92%-0.16+0.002026-08-05 → 2026-08-30
tmin12Znearest365d26 1 QC1.61 [1.24, 1.95]1.43-0.66 [-1.68, 0.64]1.94 [1.45, 2.33]35% [20%, 45%]73%92%-0.16+0.002026-08-05 → 2026-08-30
tmin12Znearestall26 1 QC1.61 [1.15, 1.96]1.43-0.66 [-1.70, 0.56]1.94 [1.31, 2.36]35% [21%, 46%]73%92%-0.16+0.002026-08-05 → 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 ECMWF AIFS Single at KSAT, lead day 4, 00Z bilinear tmax+5+2.50-2.5-52026-08-05: -1.83 °F2026-08-06: -3.12 °F2026-08-07: -3.3 °F2026-08-08: -3.07 °F2026-08-09: -3.41 °F2026-08-10: -3.32 °F2026-08-11: -1.95 °F2026-08-12: -1.88 °F2026-08-13: -4.06 °F2026-08-14: -3.94 °F2026-08-15: -3 °F2026-08-16: -1.29 °F2026-08-17: -2.9 °F2026-08-18: -2.69 °F2026-08-19: -2.98 °F2026-08-20: -3.48 °F2026-08-21: -3.66 °F2026-08-22: -3.91 °F2026-08-23: -3.92 °F2026-08-24: -3.04 °F2026-08-25: -1.88 °F2026-08-26: -1.16 °F2026-08-27: -4.65 °F2026-08-28: -3.06 °F2026-08-29: -1.06 °F2026-08-30: -0.87 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-0.87
2026-08-29-1.06
2026-08-28-3.06
2026-08-27-4.65
2026-08-26-1.16
2026-08-25-1.88
2026-08-24-3.04
2026-08-23-3.92
2026-08-22-3.91
2026-08-21-3.66
2026-08-20-3.48
2026-08-19-2.98
2026-08-18-2.69
2026-08-17-2.90
2026-08-16-1.29
2026-08-15-3.00
2026-08-14-3.94
2026-08-13-4.06
2026-08-12-1.88
2026-08-11-1.95
2026-08-10-3.32
2026-08-09-3.41
2026-08-08-3.07
2026-08-07-3.30
2026-08-06-3.12
2026-08-05-1.83

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAT, lead day 4-5 to -4.5 °F: 1 day-4.5 to -4 °F: 1 day-4 to -3.5 °F: 4 days-3.5 to -3 °F: 8 days-3 to -2.5 °F: 4 days-2.5 to -2 °F: 0 days-2 to -1.5 °F: 4 days-1.5 to -1 °F: 3 days-1 to -0.5 °F: 1 day-0.5 to 0 °F: 0 days0 to 0.5 °F: 0 days0.5 to 1 °F: 0 days1 to 1.5 °F: 0 days1.5 to 2 °F: 0 days2 to 2.5 °F: 0 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 3.05 · P90 |e| 3.93 °F-50+5 °Fn = 26 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
-5.00-4.501
-4.50-4.001
-4.00-3.504
-3.50-3.008
-3.00-2.504
-2.50-2.000
-2.00-1.504
-1.50-1.003
-1.00-0.501
-0.50+0.000
+0.00+0.500
+0.50+1.000
+1.00+1.500
+1.50+2.000
+2.00+2.500
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08262.82 -2.82

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
NCEP GFS 26 +1.12 [-0.23, 1.90] no
GraphCast (IFS init) 25 -2.62 [-3.81, -0.89] yes
ECMWF IFS HRES 20 +0.13 [-0.62, 0.85] no
Persistence (baseline) 26 +1.05 [0.18, 1.74] yes

Cite this page

ShortCastCheck, KSAT aifs_single lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAT/model/aifs_single/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAT (San Antonio Intl), model aifs_single, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSAT/model/aifs_single/lead/4/

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