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

San Diego Lindbergh · ECMWF AIFS Single · lead day 1

KSAN · aifs_single · lead 1

Target day = initialization date + 1 day. 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
tmax00Zbilinear30d29 1 QC3.81 [3.17, 4.39]1.38-3.81 [-4.39, -3.17]4.16 [3.53, 4.66]10% [0%, 29%]14%31%-1.08+0.252026-08-02 → 2026-08-30
tmax00Zbilinear90d29 1 QC3.81 [3.04, 4.44]1.38-3.81 [-4.44, -3.04]4.16 [3.47, 4.65]10% [0%, 35%]14%31%-1.08+0.252026-08-02 → 2026-08-30
tmax00Zbilinear365d29 1 QC3.81 [3.05, 4.43]1.38-3.81 [-4.43, -3.05]4.16 [3.45, 4.69]10% [0%, 39%]14%31%-1.08+0.252026-08-02 → 2026-08-30
tmax00Zbilinearall29 1 QC3.81 [2.99, 4.54]1.38-3.81 [-4.54, -2.99]4.16 [3.43, 4.75]10% [0%, 35%]14%31%-1.08+0.252026-08-02 → 2026-08-30
tmax00Znearest30d29 1 QC5.14 [4.44, 5.78]1.42-5.14 [-5.78, -4.44]5.43 [4.70, 6.04]0% [0%, 0%]0%14%-1.81+0.232026-08-02 → 2026-08-30
tmax00Znearest90d29 1 QC5.14 [4.35, 5.79]1.42-5.14 [-5.79, -4.35]5.43 [4.65, 6.00]0% [0%, 0%]0%14%-1.81+0.232026-08-02 → 2026-08-30
tmax00Znearest365d29 1 QC5.14 [4.32, 5.83]1.42-5.14 [-5.83, -4.32]5.43 [4.62, 6.09]0% [0%, 0%]0%14%-1.81+0.232026-08-02 → 2026-08-30
tmax00Znearestall29 1 QC5.14 [4.29, 5.91]1.42-5.14 [-5.91, -4.29]5.43 [4.58, 6.11]0% [0%, 0%]0%14%-1.81+0.232026-08-02 → 2026-08-30
tmax12Zbilinear30d29 1 QC4.10 [3.52, 4.64]1.26-4.10 [-4.64, -3.52]4.38 [3.76, 4.85]0% [0%, 0%]14%24%-1.25+0.312026-08-02 → 2026-08-30
tmax12Zbilinear90d29 1 QC4.10 [3.43, 4.66]1.26-4.10 [-4.66, -3.43]4.38 [3.68, 4.84]0% [0%, 0%]14%24%-1.25+0.312026-08-02 → 2026-08-30
tmax12Zbilinear365d29 1 QC4.10 [3.43, 4.68]1.26-4.10 [-4.68, -3.43]4.38 [3.66, 4.88]0% [0%, 0%]14%24%-1.25+0.312026-08-02 → 2026-08-30
tmax12Zbilinearall29 1 QC4.10 [3.42, 4.76]1.26-4.10 [-4.76, -3.42]4.38 [3.67, 4.94]0% [0%, 0%]14%24%-1.25+0.312026-08-02 → 2026-08-30
tmax12Znearest30d29 1 QC5.43 [4.76, 6.01]1.31-5.43 [-6.01, -4.76]5.66 [4.96, 6.22]0% [0%, 0%]0%7%-1.97+0.292026-08-02 → 2026-08-30
tmax12Znearest90d29 1 QC5.43 [4.71, 5.99]1.31-5.43 [-5.99, -4.71]5.66 [4.90, 6.20]0% [0%, 0%]0%7%-1.97+0.292026-08-02 → 2026-08-30
tmax12Znearest365d29 1 QC5.43 [4.68, 6.08]1.31-5.43 [-6.08, -4.68]5.66 [4.85, 6.28]0% [0%, 0%]0%7%-1.97+0.292026-08-02 → 2026-08-30
tmax12Znearestall29 1 QC5.43 [4.66, 6.12]1.31-5.43 [-6.12, -4.66]5.66 [4.81, 6.32]0% [0%, 0%]0%7%-1.97+0.292026-08-02 → 2026-08-30
tmin00Zbilinear30d29 1 QC1.52 [1.09, 1.92]0.88-1.31 [-1.92, -0.57]1.74 [1.30, 2.10]28% [10%, 50%]72%97%-1.00-0.082026-08-02 → 2026-08-30
tmin00Zbilinear90d29 1 QC1.52 [1.01, 1.99]0.88-1.31 [-1.98, -0.36]1.74 [1.20, 2.18]28% [8%, 50%]72%97%-1.00-0.082026-08-02 → 2026-08-30
tmin00Zbilinear365d29 1 QC1.52 [0.92, 1.98]0.88-1.31 [-1.98, -0.24]1.74 [1.13, 2.16]28% [6%, 54%]72%97%-1.00-0.082026-08-02 → 2026-08-30
tmin00Zbilinearall29 1 QC1.52 [0.94, 1.96]0.88-1.31 [-1.96, -0.39]1.74 [1.15, 2.16]28% [7%, 53%]72%97%-1.00-0.082026-08-02 → 2026-08-30
tmin00Znearest30d29 1 QC1.55 [1.11, 2.00]0.81-1.47 [-1.99, -0.91]1.79 [1.34, 2.21]31% [14%, 48%]72%93%-1.04+0.012026-08-02 → 2026-08-30
tmin00Znearest90d29 1 QC1.55 [1.00, 2.09]0.81-1.47 [-2.09, -0.77]1.79 [1.23, 2.28]31% [11%, 54%]72%93%-1.04+0.012026-08-02 → 2026-08-30
tmin00Znearest365d29 1 QC1.55 [0.91, 2.07]0.81-1.47 [-2.07, -0.65]1.79 [1.16, 2.27]31% [11%, 57%]72%93%-1.04+0.012026-08-02 → 2026-08-30
tmin00Znearestall29 1 QC1.55 [1.01, 2.07]0.81-1.47 [-2.07, -0.76]1.79 [1.25, 2.29]31% [11%, 54%]72%93%-1.04+0.012026-08-02 → 2026-08-30
tmin12Zbilinear30d29 1 QC1.37 [0.99, 1.73]0.81-1.19 [-1.71, -0.62]1.56 [1.20, 1.86]34% [14%, 55%]83%97%-0.80+0.022026-08-02 → 2026-08-30
tmin12Zbilinear90d29 1 QC1.37 [0.96, 1.77]0.81-1.19 [-1.76, -0.52]1.56 [1.16, 1.91]34% [13%, 57%]83%97%-0.80+0.022026-08-02 → 2026-08-30
tmin12Zbilinear365d29 1 QC1.37 [0.93, 1.75]0.81-1.19 [-1.75, -0.41]1.56 [1.15, 1.90]34% [12%, 58%]83%97%-0.80+0.022026-08-02 → 2026-08-30
tmin12Zbilinearall29 1 QC1.37 [0.89, 1.76]0.81-1.19 [-1.76, -0.51]1.56 [1.12, 1.90]34% [12%, 60%]83%97%-0.80+0.022026-08-02 → 2026-08-30
tmin12Znearest30d29 1 QC1.43 [1.10, 1.79]0.75-1.35 [-1.77, -0.92]1.63 [1.28, 1.97]38% [21%, 60%]72%97%-0.89+0.092026-08-02 → 2026-08-30
tmin12Znearest90d29 1 QC1.43 [1.06, 1.87]0.75-1.35 [-1.87, -0.84]1.63 [1.25, 2.02]38% [18%, 62%]72%97%-0.89+0.092026-08-02 → 2026-08-30
tmin12Znearest365d29 1 QC1.43 [1.03, 1.85]0.75-1.35 [-1.85, -0.78]1.63 [1.23, 2.00]38% [18%, 67%]72%97%-0.89+0.092026-08-02 → 2026-08-30
tmin12Znearestall29 1 QC1.43 [1.05, 1.87]0.75-1.35 [-1.86, -0.84]1.63 [1.24, 2.01]38% [19%, 62%]72%97%-0.89+0.092026-08-02 → 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 1, 00Z bilinear tmax+10+50-5-102026-08-02: -3.24 °F2026-08-03: -2.7 °F2026-08-04: -2.79 °F2026-08-05: -4.93 °F2026-08-06: -5.38 °F2026-08-07: -4.65 °F2026-08-08: -3.29 °F2026-08-09: -5.31 °F2026-08-10: -6.32 °F2026-08-11: -4.83 °F2026-08-12: -4.7 °F2026-08-13: -3.17 °F2026-08-14: -3.81 °F2026-08-15: -3.02 °F2026-08-16: -1.52 °F2026-08-17: -3.58 °F2026-08-18: -2.65 °F2026-08-19: -3.05 °F2026-08-20: -5.62 °F2026-08-21: -4.45 °F2026-08-22: -2.84 °F2026-08-23: -7.28 °F2026-08-24: -2.93 °F2026-08-25: -3.72 °F2026-08-26: -6.85 °F2026-08-27: -0.44 °F2026-08-28: -0.97 °F2026-08-29: -5.4 °F2026-08-30: -0.94 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-0.94
2026-08-29-5.40
2026-08-28-0.97
2026-08-27-0.44
2026-08-26-6.85
2026-08-25-3.72
2026-08-24-2.93
2026-08-23-7.28
2026-08-22-2.84
2026-08-21-4.45
2026-08-20-5.62
2026-08-19-3.05
2026-08-18-2.65
2026-08-17-3.58
2026-08-16-1.52
2026-08-15-3.02
2026-08-14-3.81
2026-08-13-3.17
2026-08-12-4.70
2026-08-11-4.83
2026-08-10-6.32
2026-08-09-5.31
2026-08-08-3.29
2026-08-07-4.65
2026-08-06-5.38
2026-08-05-4.93
2026-08-04-2.79
2026-08-03-2.70
2026-08-02-3.24

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 2 days-6 to -5 °F: 4 days-5 to -4 °F: 5 days-4 to -3 °F: 8 days-3 to -2 °F: 5 days-2 to -1 °F: 1 day-1 to 0 °F: 3 days0 to 1 °F: 0 days1 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| 3.58 · P90 |e| 5.76 °F-100+10 °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
-10.00-9.000
-9.00-8.000
-8.00-7.001
-7.00-6.002
-6.00-5.004
-5.00-4.005
-4.00-3.008
-3.00-2.005
-2.00-1.001
-1.00+0.003
+0.00+1.000
+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
2026-08293.81 -3.81

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29

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
Aurora (GFS init) 1 -3.12 [-3.12, -3.12] yes
Aurora (IFS init) 2 -2.01 [-2.28, -1.74] yes
FourCastNet v2 (GFS init) 1 +0.40 [0.40, 0.40] yes
FourCastNet v2 (IFS init) 2 +0.62 [0.44, 0.79] yes
NCEP GFS 29 +1.13 [0.19, 2.08] yes
GraphCast (GFS init) 1 -2.57 [-2.57, -2.57] yes
GraphCast (IFS init) 27 -1.84 [-2.56, -1.29] yes
ECMWF IFS HRES 22 -1.98 [-2.54, -1.46] yes
Pangu-Weather (GFS init) 1 -4.03 [-4.03, -4.03] yes
Pangu-Weather (IFS init) 2 -3.24 [-3.55, -2.92] yes
Persistence (baseline) 29 +1.98 [0.12, 3.27] yes

Cite this page

ShortCastCheck, KSAN aifs_single lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model aifs_single, lead day 1. 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/1/

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