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

San Diego Lindbergh · ECMWF AIFS Single · lead day 0

KSAN · aifs_single · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d30 1 QC3.97 [3.44, 4.47]1.11-3.97 [-4.47, -3.44]4.23 [3.66, 4.68]3% [0%, 10%]7%20%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d30 1 QC3.97 [3.33, 4.48]1.11-3.97 [-4.48, -3.33]4.23 [3.60, 4.64]3% [0%, 11%]7%20%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d30 1 QC3.97 [3.36, 4.49]1.11-3.97 [-4.49, -3.36]4.23 [3.61, 4.72]3% [0%, 12%]7%20%——2026-08-01 → 2026-08-30
tmax00Zbilinearall30 1 QC3.97 [3.34, 4.55]1.11-3.97 [-4.55, -3.34]4.23 [3.61, 4.75]3% [0%, 11%]7%20%——2026-08-01 → 2026-08-30
tmax00Znearest30d30 1 QC5.30 [4.73, 5.86]1.19-5.30 [-5.86, -4.73]5.52 [4.89, 6.08]0% [0%, 0%]0%7%——2026-08-01 → 2026-08-30
tmax00Znearest90d30 1 QC5.30 [4.63, 5.82]1.19-5.30 [-5.82, -4.63]5.52 [4.80, 6.05]0% [0%, 0%]0%7%——2026-08-01 → 2026-08-30
tmax00Znearest365d30 1 QC5.30 [4.60, 5.89]1.19-5.30 [-5.89, -4.60]5.52 [4.77, 6.09]0% [0%, 0%]0%7%——2026-08-01 → 2026-08-30
tmax00Znearestall30 1 QC5.30 [4.62, 5.95]1.19-5.30 [-5.95, -4.62]5.52 [4.77, 6.15]0% [0%, 0%]0%7%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d30 1 QC1.34 [1.00, 1.68]0.76-1.18 [-1.67, -0.62]1.53 [1.16, 1.87]33% [13%, 57%]83%97%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d30 1 QC1.34 [0.94, 1.71]0.76-1.18 [-1.71, -0.52]1.53 [1.13, 1.93]33% [14%, 57%]83%97%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d30 1 QC1.34 [0.92, 1.70]0.76-1.18 [-1.70, -0.45]1.53 [1.11, 1.88]33% [14%, 59%]83%97%——2026-08-01 → 2026-08-30
tmin00Zbilinearall30 1 QC1.34 [0.89, 1.72]0.76-1.18 [-1.72, -0.52]1.53 [1.07, 1.90]33% [14%, 61%]83%97%——2026-08-01 → 2026-08-30
tmin00Znearest30d30 1 QC1.42 [1.12, 1.78]0.70-1.32 [-1.76, -0.90]1.60 [1.26, 1.97]30% [13%, 50%]83%97%——2026-08-01 → 2026-08-30
tmin00Znearest90d30 1 QC1.42 [1.08, 1.82]0.70-1.32 [-1.82, -0.84]1.60 [1.24, 2.04]30% [10%, 51%]83%97%——2026-08-01 → 2026-08-30
tmin00Znearest365d30 1 QC1.42 [1.06, 1.80]0.70-1.32 [-1.80, -0.82]1.60 [1.23, 1.98]30% [10%, 53%]83%97%——2026-08-01 → 2026-08-30
tmin00Znearestall30 1 QC1.42 [1.07, 1.80]0.70-1.32 [-1.80, -0.84]1.60 [1.20, 2.00]30% [10%, 56%]83%97%——2026-08-01 → 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 0, 00Z bilinear tmax+10+50-5-102026-08-01: -3.33 °F2026-08-02: -3.91 °F2026-08-03: -2.94 °F2026-08-04: -3.34 °F2026-08-05: -4.79 °F2026-08-06: -5.5 °F2026-08-07: -3.97 °F2026-08-08: -3.98 °F2026-08-09: -6.09 °F2026-08-10: -5.47 °F2026-08-11: -4.2 °F2026-08-12: -4.87 °F2026-08-13: -3.8 °F2026-08-14: -3.98 °F2026-08-15: -3 °F2026-08-16: -2.29 °F2026-08-17: -3.76 °F2026-08-18: -3.25 °F2026-08-19: -2.98 °F2026-08-20: -5.4 °F2026-08-21: -3.45 °F2026-08-22: -3.42 °F2026-08-23: -7.22 °F2026-08-24: -3.15 °F2026-08-25: -4.43 °F2026-08-26: -7.2 °F2026-08-27: -0.81 °F2026-08-28: -2.03 °F2026-08-29: -5.13 °F2026-08-30: -1.36 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.36
2026-08-29-5.13
2026-08-28-2.03
2026-08-27-0.81
2026-08-26-7.20
2026-08-25-4.43
2026-08-24-3.15
2026-08-23-7.22
2026-08-22-3.42
2026-08-21-3.45
2026-08-20-5.40
2026-08-19-2.98
2026-08-18-3.25
2026-08-17-3.76
2026-08-16-2.29
2026-08-15-3.00
2026-08-14-3.98
2026-08-13-3.80
2026-08-12-4.87
2026-08-11-4.20
2026-08-10-5.47
2026-08-09-6.09
2026-08-08-3.98
2026-08-07-3.97
2026-08-06-5.50
2026-08-05-4.79
2026-08-04-3.34
2026-08-03-2.94
2026-08-02-3.91
2026-08-01-3.33

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 0-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 2 days-7 to -6 °F: 1 day-6 to -5 °F: 4 days-5 to -4 °F: 4 days-4 to -3 °F: 13 days-3 to -2 °F: 4 days-2 to -1 °F: 1 day-1 to 0 °F: 1 day0 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| 3.86 · P90 |e| 5.56 °F-100+10 °Fn = 30 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
-8.00-7.002
-7.00-6.001
-6.00-5.004
-5.00-4.004
-4.00-3.0013
-3.00-2.004
-2.00-1.001
-1.00+0.001
+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
2026-08303.97 -3.97

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-01 → 2026-08-30 30
ECMWF AIFS Single2026-08-01 → 2026-08-30 30

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) 2 -2.54 [-2.86, -2.22] yes
Aurora (IFS init) 3 -1.83 [-2.15, -1.67] yes
FourCastNet v2 (GFS init) 2 +0.31 [-0.34, 0.96] no
FourCastNet v2 (IFS init) 3 +0.15 [-0.14, 0.54] no
NCEP GFS 30 +1.04 [0.32, 1.83] yes
GraphCast (GFS init) 2 -2.06 [-2.26, -1.86] yes
GraphCast (IFS init) 28 -1.47 [-1.97, -0.99] yes
ECMWF IFS HRES 25 -1.80 [-2.64, -1.19] yes
Pangu-Weather (GFS init) 2 -2.14 [-2.64, -1.63] yes
Pangu-Weather (IFS init) 3 -2.67 [-2.90, -2.22] yes

Cite this page

ShortCastCheck, KSAN aifs_single lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model aifs_single, lead day 0. 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/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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