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

San Diego Lindbergh · ECMWF AIFS Single · lead day 6

KSAN · aifs_single · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d24 1 QC3.40 [2.27, 4.53]1.94-3.20 [-4.47, -1.82]4.03 [2.68, 5.09]12% [0%, 24%]38%46%-0.10+0.332026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC3.40 [2.20, 4.57]1.94-3.20 [-4.50, -1.68]4.03 [2.60, 5.15]12% [0%, 25%]38%46%-0.10+0.332026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC3.40 [2.07, 4.69]1.94-3.20 [-4.63, -1.57]4.03 [2.46, 5.28]12% [0%, 27%]38%46%-0.10+0.332026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC3.40 [2.05, 4.79]1.94-3.20 [-4.76, -1.56]4.03 [2.41, 5.42]12% [0%, 25%]38%46%-0.10+0.332026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC4.48 [3.07, 5.82]1.99-4.45 [-5.82, -3.01]5.09 [3.61, 6.30]8% [0%, 20%]8%38%-0.45+0.322026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC4.48 [2.99, 5.86]1.99-4.45 [-5.86, -2.91]5.09 [3.50, 6.35]8% [0%, 21%]8%38%-0.45+0.322026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC4.48 [2.82, 5.99]1.99-4.45 [-5.99, -2.74]5.09 [3.29, 6.51]8% [0%, 22%]8%38%-0.45+0.322026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC4.48 [2.89, 6.11]1.99-4.45 [-6.11, -2.79]5.09 [3.29, 6.65]8% [0%, 21%]8%38%-0.45+0.322026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC3.84 [2.35, 5.14]2.13-3.84 [-5.14, -2.35]4.64 [3.05, 5.81]12% [0%, 33%]33%46%-0.24+0.272026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC3.84 [2.27, 5.25]2.13-3.84 [-5.25, -2.27]4.64 [2.96, 5.86]12% [0%, 33%]33%46%-0.24+0.272026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC3.84 [2.07, 5.35]2.13-3.84 [-5.35, -2.07]4.64 [2.70, 5.93]12% [0%, 38%]33%46%-0.24+0.272026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC3.84 [2.09, 5.45]2.13-3.84 [-5.45, -2.09]4.64 [2.72, 6.09]12% [0%, 33%]33%46%-0.24+0.272026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC5.13 [3.57, 6.50]2.15-5.13 [-6.50, -3.57]5.77 [4.06, 7.10]0% [0%, 0%]8%29%-0.66+0.262026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC5.13 [3.53, 6.61]2.15-5.13 [-6.61, -3.53]5.77 [3.97, 7.12]0% [0%, 0%]8%29%-0.66+0.262026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC5.13 [3.27, 6.75]2.15-5.13 [-6.75, -3.27]5.77 [3.68, 7.21]0% [0%, 0%]8%29%-0.66+0.262026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC5.13 [3.30, 6.89]2.15-5.13 [-6.89, -3.30]5.77 [3.68, 7.40]0% [0%, 0%]8%29%-0.66+0.262026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC0.85 [0.67, 1.05]0.75-0.51 [-0.79, -0.26]0.99 [0.82, 1.15]62% [37%, 82%]96%100%+0.52+0.542026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC0.85 [0.68, 1.10]0.75-0.51 [-0.86, -0.25]0.99 [0.82, 1.19]62% [31%, 83%]96%100%+0.52+0.542026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC0.85 [0.67, 1.09]0.75-0.51 [-0.86, -0.24]0.99 [0.79, 1.17]62% [33%, 85%]96%100%+0.52+0.542026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC0.85 [0.66, 1.12]0.75-0.51 [-0.87, -0.24]0.99 [0.80, 1.20]62% [33%, 84%]96%100%+0.52+0.542026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC0.90 [0.67, 1.17]0.74-0.64 [-0.96, -0.35]1.08 [0.83, 1.31]62% [37%, 82%]96%100%+0.49+0.552026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC0.90 [0.66, 1.24]0.74-0.64 [-1.04, -0.35]1.08 [0.81, 1.34]62% [31%, 83%]96%100%+0.49+0.552026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC0.90 [0.64, 1.20]0.74-0.64 [-1.05, -0.31]1.08 [0.77, 1.34]62% [33%, 85%]96%100%+0.49+0.552026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC0.90 [0.64, 1.25]0.74-0.64 [-1.07, -0.33]1.08 [0.78, 1.37]62% [33%, 84%]96%100%+0.49+0.552026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC1.12 [0.85, 1.46]0.75-1.05 [-1.41, -0.78]1.35 [1.05, 1.67]50% [30%, 67%]79%100%+0.36+0.542026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC1.12 [0.81, 1.56]0.75-1.05 [-1.50, -0.76]1.35 [1.01, 1.75]50% [25%, 67%]79%100%+0.36+0.542026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC1.12 [0.78, 1.55]0.75-1.05 [-1.46, -0.73]1.35 [0.95, 1.74]50% [26%, 70%]79%100%+0.36+0.542026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC1.12 [0.81, 1.56]0.75-1.05 [-1.50, -0.74]1.35 [0.98, 1.75]50% [25%, 68%]79%100%+0.36+0.542026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC1.22 [0.96, 1.58]0.68-1.22 [-1.58, -0.96]1.45 [1.15, 1.82]38% [25%, 47%]79%100%+0.30+0.582026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC1.22 [0.94, 1.67]0.68-1.22 [-1.67, -0.94]1.45 [1.11, 1.88]38% [23%, 48%]79%100%+0.30+0.582026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC1.22 [0.91, 1.60]0.68-1.22 [-1.60, -0.91]1.45 [1.06, 1.86]38% [25%, 50%]79%100%+0.30+0.582026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC1.22 [0.95, 1.62]0.68-1.22 [-1.62, -0.95]1.45 [1.11, 1.88]38% [25%, 50%]79%100%+0.30+0.582026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: -3.66 °F2026-08-08: -2.99 °F2026-08-09: -4.85 °F2026-08-10: -4.41 °F2026-08-11: -4.1 °F2026-08-12: -4.42 °F2026-08-13: -1.36 °F2026-08-14: -2.31 °F2026-08-15: -1.76 °F2026-08-16: +1.62 °F2026-08-17: -0.81 °F2026-08-18: -1.26 °F2026-08-19: +0.84 °F2026-08-20: -3.4 °F2026-08-21: -3.4 °F2026-08-22: -5.09 °F2026-08-23: -10.03 °F2026-08-24: -4.87 °F2026-08-25: -5.63 °F2026-08-26: -5.71 °F2026-08-27: -1.37 °F2026-08-28: -0.6 °F2026-08-29: -5.3 °F2026-08-30: -1.87 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.87
2026-08-29-5.30
2026-08-28-0.60
2026-08-27-1.37
2026-08-26-5.71
2026-08-25-5.63
2026-08-24-4.87
2026-08-23-10.03
2026-08-22-5.09
2026-08-21-3.40
2026-08-20-3.40
2026-08-19+0.84
2026-08-18-1.26
2026-08-17-0.81
2026-08-16+1.62
2026-08-15-1.76
2026-08-14-2.31
2026-08-13-1.36
2026-08-12-4.42
2026-08-11-4.10
2026-08-10-4.41
2026-08-09-4.85
2026-08-08-2.99
2026-08-07-3.66

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 6-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 9 days-4 to -2 °F: 5 days-2 to 0 °F: 7 days0 to 2 °F: 2 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.4 · P90 |e| 5.53 °F-200+20 °Fn = 24 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.000
-8.00-6.000
-6.00-4.009
-4.00-2.005
-2.00+0.007
+0.00+2.002
+2.00+4.000
+4.00+6.000
+6.00+8.000
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08243.40 -3.20

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24

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 24 +0.01 [-1.06, 0.82] no
GraphCast (IFS init) 24 -2.18 [-3.03, -1.24] yes
ECMWF IFS HRES 19 -2.35 [-3.44, -1.15] yes
Persistence (baseline) 24 +0.32 [-0.51, 1.57] no

Cite this page

ShortCastCheck, KSAN aifs_single lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/aifs_single/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model aifs_single, lead day 6. 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/6/

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