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

San Diego Lindbergh · ECMWF AIFS Single · lead day 8

KSAN · aifs_single · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d22 1 QC3.58 [2.53, 4.69]2.19-3.36 [-4.55, -2.12]4.23 [3.20, 5.17]23% [6%, 39%]27%36%+0.01+0.332026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC3.58 [2.49, 4.79]2.19-3.36 [-4.75, -1.96]4.23 [3.15, 5.25]23% [0%, 40%]27%36%+0.01+0.332026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC3.58 [2.45, 4.86]2.19-3.36 [-4.79, -1.87]4.23 [3.13, 5.30]23% [0%, 43%]27%36%+0.01+0.332026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC3.58 [2.39, 4.93]2.19-3.36 [-4.79, -1.76]4.23 [3.09, 5.41]23% [0%, 42%]27%36%+0.01+0.332026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC4.55 [3.33, 5.84]2.28-4.47 [-5.79, -3.16]5.18 [3.92, 6.30]5% [0%, 19%]27%36%-0.25+0.312026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC4.55 [3.25, 6.03]2.28-4.47 [-6.01, -3.07]5.18 [3.88, 6.41]5% [0%, 22%]27%36%-0.25+0.312026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC4.55 [3.20, 6.06]2.28-4.47 [-6.04, -3.02]5.18 [3.81, 6.47]5% [0%, 22%]27%36%-0.25+0.312026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC4.55 [3.14, 6.14]2.28-4.47 [-6.14, -2.83]5.18 [3.79, 6.61]5% [0%, 26%]27%36%-0.25+0.312026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC4.09 [3.08, 5.12]1.82-3.81 [-5.00, -2.47]4.59 [3.32, 5.69]5% [0%, 12%]5%36%-0.13+0.452026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC4.09 [2.94, 5.22]1.82-3.81 [-5.19, -2.13]4.59 [3.15, 5.73]5% [0%, 12%]5%36%-0.13+0.452026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC4.09 [2.93, 5.30]1.82-3.81 [-5.29, -2.04]4.59 [3.13, 5.86]5% [0%, 14%]5%36%-0.13+0.452026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC4.09 [2.99, 5.35]1.82-3.81 [-5.35, -1.68]4.59 [3.17, 5.93]5% [0%, 14%]5%36%-0.13+0.452026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC5.13 [3.99, 6.27]1.83-4.99 [-6.22, -3.66]5.59 [4.22, 6.76]0% [0%, 0%]9%9%-0.41+0.442026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC5.13 [3.82, 6.48]1.83-4.99 [-6.48, -3.41]5.59 [4.14, 6.84]0% [0%, 0%]9%9%-0.41+0.442026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC5.13 [3.84, 6.53]1.83-4.99 [-6.52, -3.35]5.59 [4.12, 7.00]0% [0%, 0%]9%9%-0.41+0.442026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC5.13 [3.69, 6.62]1.83-4.99 [-6.62, -3.07]5.59 [4.04, 7.09]0% [0%, 0%]9%9%-0.41+0.442026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC1.14 [0.92, 1.38]1.04-0.47 [-1.03, 0.20]1.37 [1.04, 1.67]59% [38%, 76%]91%95%+0.34+0.372026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC1.14 [0.87, 1.43]1.04-0.47 [-1.13, 0.36]1.37 [1.00, 1.70]59% [33%, 78%]91%95%+0.34+0.372026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC1.14 [0.87, 1.43]1.04-0.47 [-1.08, 0.40]1.37 [1.00, 1.73]59% [33%, 80%]91%95%+0.34+0.372026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC1.14 [0.86, 1.43]1.04-0.47 [-1.10, 0.39]1.37 [0.98, 1.75]59% [35%, 79%]91%95%+0.34+0.372026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC1.11 [0.84, 1.39]1.04-0.47 [-1.05, 0.20]1.36 [0.99, 1.68]41% [21%, 58%]91%95%+0.36+0.372026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC1.11 [0.78, 1.47]1.04-0.47 [-1.20, 0.37]1.36 [0.94, 1.72]41% [15%, 60%]91%95%+0.36+0.372026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC1.11 [0.78, 1.51]1.04-0.47 [-1.15, 0.42]1.36 [0.90, 1.74]41% [18%, 60%]91%95%+0.36+0.372026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC1.11 [0.77, 1.48]1.04-0.47 [-1.15, 0.44]1.36 [0.91, 1.74]41% [16%, 67%]91%95%+0.36+0.372026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC1.26 [0.97, 1.52]0.81-1.02 [-1.47, -0.49]1.46 [1.14, 1.68]41% [25%, 57%]86%95%+0.27+0.512026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC1.26 [0.94, 1.58]0.81-1.02 [-1.56, -0.41]1.46 [1.08, 1.70]41% [20%, 60%]86%95%+0.27+0.512026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC1.26 [0.94, 1.58]0.81-1.02 [-1.58, -0.40]1.46 [1.08, 1.71]41% [20%, 60%]86%95%+0.27+0.512026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC1.26 [0.91, 1.59]0.81-1.02 [-1.57, -0.33]1.46 [1.08, 1.71]41% [21%, 61%]86%95%+0.27+0.512026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC1.23 [0.93, 1.53]0.75-1.11 [-1.47, -0.71]1.45 [1.14, 1.68]45% [26%, 62%]86%95%+0.29+0.552026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC1.23 [0.88, 1.58]0.75-1.11 [-1.55, -0.72]1.45 [1.08, 1.72]45% [20%, 64%]86%95%+0.29+0.552026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC1.23 [0.89, 1.56]0.75-1.11 [-1.54, -0.71]1.45 [1.06, 1.70]45% [23%, 64%]86%95%+0.29+0.552026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC1.23 [0.84, 1.58]0.75-1.11 [-1.56, -0.63]1.45 [1.06, 1.71]45% [23%, 67%]86%95%+0.29+0.552026-08-09 → 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 8, 00Z bilinear tmax+10+50-5-102026-08-09: -4.62 °F2026-08-10: -4.96 °F2026-08-11: -4.13 °F2026-08-12: -3.38 °F2026-08-13: -0.81 °F2026-08-14: -3.34 °F2026-08-15: -2.06 °F2026-08-16: -0.56 °F2026-08-17: -5.44 °F2026-08-18: -0.41 °F2026-08-19: +0.31 °F2026-08-20: -4.6 °F2026-08-21: -4.07 °F2026-08-22: -4.99 °F2026-08-23: -8.05 °F2026-08-24: -6.69 °F2026-08-25: -5.46 °F2026-08-26: -5.45 °F2026-08-27: -1.35 °F2026-08-28: -0.02 °F2026-08-29: -5.92 °F2026-08-30: +2.18 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+2.18
2026-08-29-5.92
2026-08-28-0.02
2026-08-27-1.35
2026-08-26-5.45
2026-08-25-5.46
2026-08-24-6.69
2026-08-23-8.05
2026-08-22-4.99
2026-08-21-4.07
2026-08-20-4.60
2026-08-19+0.31
2026-08-18-0.41
2026-08-17-5.44
2026-08-16-0.56
2026-08-15-2.06
2026-08-14-3.34
2026-08-13-0.81
2026-08-12-3.38
2026-08-11-4.13
2026-08-10-4.96
2026-08-09-4.62

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 4 days-5 to -4 °F: 6 days-4 to -3 °F: 2 days-3 to -2 °F: 1 day-2 to -1 °F: 1 day-1 to 0 °F: 4 days0 to 1 °F: 1 day1 to 2 °F: 0 days2 to 3 °F: 1 day3 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| 4.1 · P90 |e| 5.88 °F-100+10 °Fn = 22 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
-9.00-8.001
-8.00-7.000
-7.00-6.001
-6.00-5.004
-5.00-4.006
-4.00-3.002
-3.00-2.001
-2.00-1.001
-1.00+0.004
+0.00+1.001
+1.00+2.000
+2.00+3.001
+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
2026-08223.58 -3.36

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22

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 22 -0.25 [-1.65, 0.75] no
GraphCast (IFS init) 22 -2.33 [-3.77, -1.03] yes
ECMWF IFS HRES 17 -2.62 [-3.92, -0.43] yes
Persistence (baseline) 22 -0.05 [-1.07, 1.49] no

Cite this page

ShortCastCheck, KSAN aifs_single lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model aifs_single, lead day 8. 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/8/

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