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

San Diego Lindbergh · ECMWF AIFS Single · lead day 3

KSAN · aifs_single · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d27 1 QC3.54 [2.71, 4.25]1.68-3.47 [-4.22, -2.62]3.98 [3.16, 4.58]11% [0%, 24%]19%48%-0.65+0.192026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC3.54 [2.64, 4.24]1.68-3.47 [-4.23, -2.49]3.98 [3.12, 4.57]11% [0%, 27%]19%48%-0.65+0.192026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC3.54 [2.60, 4.27]1.68-3.47 [-4.22, -2.47]3.98 [3.04, 4.63]11% [0%, 29%]19%48%-0.65+0.192026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC3.54 [2.59, 4.34]1.68-3.47 [-4.34, -2.44]3.98 [3.01, 4.63]11% [0%, 29%]19%48%-0.65+0.192026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC4.79 [3.85, 5.61]1.72-4.79 [-5.61, -3.85]5.19 [4.21, 5.90]0% [0%, 0%]7%22%-1.23+0.172026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC4.79 [3.82, 5.59]1.72-4.79 [-5.59, -3.82]5.19 [4.16, 5.90]0% [0%, 0%]7%22%-1.23+0.172026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC4.79 [3.77, 5.63]1.72-4.79 [-5.63, -3.77]5.19 [4.13, 5.95]0% [0%, 0%]7%22%-1.23+0.172026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC4.79 [3.74, 5.71]1.72-4.79 [-5.71, -3.74]5.19 [4.07, 5.99]0% [0%, 0%]7%22%-1.23+0.172026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC4.02 [3.18, 4.82]1.56-4.02 [-4.82, -3.18]4.39 [3.58, 4.98]4% [0%, 12%]15%33%-0.87+0.242026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC4.02 [3.07, 4.84]1.56-4.02 [-4.84, -3.07]4.39 [3.49, 5.00]4% [0%, 12%]15%33%-0.87+0.242026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC4.02 [3.02, 4.83]1.56-4.02 [-4.83, -3.02]4.39 [3.43, 5.00]4% [0%, 13%]15%33%-0.87+0.242026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC4.02 [3.01, 4.94]1.56-4.02 [-4.94, -3.01]4.39 [3.42, 5.08]4% [0%, 12%]15%33%-0.87+0.242026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC5.34 [4.45, 6.12]1.59-5.34 [-6.12, -4.45]5.63 [4.74, 6.31]0% [0%, 0%]0%11%-1.49+0.232026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC5.34 [4.38, 6.13]1.59-5.34 [-6.13, -4.38]5.63 [4.66, 6.30]0% [0%, 0%]0%11%-1.49+0.232026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC5.34 [4.37, 6.14]1.59-5.34 [-6.14, -4.37]5.63 [4.64, 6.33]0% [0%, 0%]0%11%-1.49+0.232026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC5.34 [4.31, 6.24]1.59-5.34 [-6.24, -4.31]5.63 [4.55, 6.38]0% [0%, 0%]0%11%-1.49+0.232026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.23 [1.01, 1.47]0.95-0.79 [-1.44, 0.04]1.45 [1.19, 1.71]41% [26%, 59%]85%96%-0.19+0.092026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.23 [1.00, 1.50]0.95-0.79 [-1.49, 0.19]1.45 [1.16, 1.75]41% [24%, 60%]85%96%-0.19+0.092026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC1.23 [0.98, 1.48]0.95-0.79 [-1.48, 0.32]1.45 [1.14, 1.69]41% [25%, 64%]85%96%-0.19+0.092026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC1.23 [0.96, 1.48]0.95-0.79 [-1.48, 0.26]1.45 [1.14, 1.72]41% [23%, 62%]85%96%-0.19+0.092026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC1.18 [0.86, 1.52]0.85-0.97 [-1.49, -0.32]1.43 [1.10, 1.77]44% [30%, 61%]81%96%-0.14+0.192026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC1.18 [0.82, 1.61]0.85-0.97 [-1.61, -0.22]1.43 [1.08, 1.84]44% [28%, 62%]81%96%-0.14+0.192026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC1.18 [0.77, 1.57]0.85-0.97 [-1.57, -0.12]1.43 [1.05, 1.80]44% [28%, 64%]81%96%-0.14+0.192026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC1.18 [0.82, 1.59]0.85-0.97 [-1.59, -0.17]1.43 [1.06, 1.83]44% [27%, 63%]81%96%-0.14+0.192026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.49 [1.11, 1.89]0.91-1.22 [-1.88, -0.45]1.72 [1.36, 2.08]33% [13%, 57%]67%96%-0.44+0.132026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.49 [1.10, 1.95]0.91-1.22 [-1.95, -0.38]1.72 [1.33, 2.15]33% [11%, 60%]67%96%-0.44+0.132026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC1.49 [1.05, 1.94]0.91-1.22 [-1.94, -0.23]1.72 [1.30, 2.11]33% [10%, 63%]67%96%-0.44+0.132026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC1.49 [1.05, 1.96]0.91-1.22 [-1.96, -0.29]1.72 [1.29, 2.16]33% [12%, 62%]67%96%-0.44+0.132026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC1.55 [1.17, 1.98]0.83-1.40 [-1.93, -0.84]1.76 [1.37, 2.18]33% [19%, 48%]67%96%-0.49+0.212026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC1.55 [1.16, 2.08]0.83-1.40 [-2.07, -0.79]1.76 [1.35, 2.27]33% [19%, 50%]67%96%-0.49+0.212026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC1.55 [1.12, 2.05]0.83-1.40 [-2.05, -0.68]1.76 [1.32, 2.23]33% [18%, 50%]67%96%-0.49+0.212026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC1.55 [1.12, 2.08]0.83-1.40 [-2.08, -0.73]1.76 [1.34, 2.28]33% [19%, 50%]67%96%-0.49+0.212026-08-04 → 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 KSAN, lead day 3, 00Z bilinear tmax+10+50-5-102026-08-04: -2.24 °F2026-08-05: -4.23 °F2026-08-06: -4.95 °F2026-08-07: -3.71 °F2026-08-08: -3.99 °F2026-08-09: -5.59 °F2026-08-10: -4.76 °F2026-08-11: -4.93 °F2026-08-12: -4.82 °F2026-08-13: -2.24 °F2026-08-14: -2.66 °F2026-08-15: -2.11 °F2026-08-16: -1.3 °F2026-08-17: -2.29 °F2026-08-18: -0.92 °F2026-08-19: -2.23 °F2026-08-20: -4.54 °F2026-08-21: -5.54 °F2026-08-22: -4.33 °F2026-08-23: -7.71 °F2026-08-24: -2.64 °F2026-08-25: -2.64 °F2026-08-26: -6.42 °F2026-08-27: +0.98 °F2026-08-28: -1.45 °F2026-08-29: -5.73 °F2026-08-30: -0.64 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-0.64
2026-08-29-5.73
2026-08-28-1.45
2026-08-27+0.98
2026-08-26-6.42
2026-08-25-2.64
2026-08-24-2.64
2026-08-23-7.71
2026-08-22-4.33
2026-08-21-5.54
2026-08-20-4.54
2026-08-19-2.23
2026-08-18-0.92
2026-08-17-2.29
2026-08-16-1.30
2026-08-15-2.11
2026-08-14-2.66
2026-08-13-2.24
2026-08-12-4.82
2026-08-11-4.93
2026-08-10-4.76
2026-08-09-5.59
2026-08-08-3.99
2026-08-07-3.71
2026-08-06-4.95
2026-08-05-4.23
2026-08-04-2.24

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 3 days-5 to -4 °F: 7 days-4 to -3 °F: 2 days-3 to -2 °F: 8 days-2 to -1 °F: 2 days-1 to 0 °F: 2 days0 to 1 °F: 1 day1 to 2 °F: 0 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| 3.71 · P90 |e| 5.65 °F-100+10 °Fn = 27 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
-8.00-7.001
-7.00-6.001
-6.00-5.003
-5.00-4.007
-4.00-3.002
-3.00-2.008
-2.00-1.002
-1.00+0.002
+0.00+1.001
+1.00+2.000
+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
2026-08273.54 -3.47

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27

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 27 +0.57 [-0.62, 1.71] no
GraphCast (IFS init) 25 -2.22 [-3.36, -1.38] yes
ECMWF IFS HRES 22 -2.21 [-2.70, -1.59] yes
Persistence (baseline) 27 +1.39 [0.57, 2.14] yes

Cite this page

ShortCastCheck, KSAN aifs_single lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model aifs_single, lead day 3. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/3/

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