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

San Diego Lindbergh · ECMWF AIFS Single · lead day 2

KSAN · aifs_single · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 1 QC3.60 [2.88, 4.26]1.45-3.60 [-4.26, -2.88]3.94 [3.22, 4.47]4% [0%, 11%]18%46%-0.57+0.362026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC3.60 [2.79, 4.34]1.45-3.60 [-4.34, -2.79]3.94 [3.15, 4.53]4% [0%, 12%]18%46%-0.57+0.362026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC3.60 [2.77, 4.27]1.45-3.60 [-4.27, -2.77]3.94 [3.11, 4.49]4% [0%, 12%]18%46%-0.57+0.362026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC3.60 [2.75, 4.43]1.45-3.60 [-4.43, -2.75]3.94 [3.11, 4.61]4% [0%, 12%]18%46%-0.57+0.362026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC4.93 [4.14, 5.61]1.51-4.93 [-5.61, -4.14]5.20 [4.41, 5.80]0% [0%, 0%]0%14%-1.16+0.332026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC4.93 [4.11, 5.64]1.51-4.93 [-5.64, -4.11]5.20 [4.35, 5.83]0% [0%, 0%]0%14%-1.16+0.332026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC4.93 [4.05, 5.62]1.51-4.93 [-5.62, -4.05]5.20 [4.29, 5.84]0% [0%, 0%]0%14%-1.16+0.332026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC4.93 [4.02, 5.79]1.51-4.93 [-5.79, -4.02]5.20 [4.26, 5.92]0% [0%, 0%]0%14%-1.16+0.332026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC4.12 [3.44, 4.78]1.40-4.12 [-4.78, -3.44]4.41 [3.72, 4.95]4% [0%, 11%]4%32%-0.80+0.392026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC4.12 [3.34, 4.85]1.40-4.12 [-4.85, -3.34]4.41 [3.66, 5.01]4% [0%, 12%]4%32%-0.80+0.392026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC4.12 [3.34, 4.83]1.40-4.12 [-4.83, -3.34]4.41 [3.62, 4.98]4% [0%, 12%]4%32%-0.80+0.392026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC4.12 [3.32, 4.94]1.40-4.12 [-4.94, -3.32]4.41 [3.58, 5.09]4% [0%, 12%]4%32%-0.80+0.392026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC5.45 [4.70, 6.10]1.45-5.45 [-6.10, -4.70]5.68 [4.94, 6.27]0% [0%, 0%]0%4%-1.38+0.362026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC5.45 [4.64, 6.13]1.45-5.45 [-6.13, -4.64]5.68 [4.86, 6.28]0% [0%, 0%]0%4%-1.38+0.362026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC5.45 [4.59, 6.13]1.45-5.45 [-6.13, -4.59]5.68 [4.82, 6.29]0% [0%, 0%]0%4%-1.38+0.362026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC5.45 [4.59, 6.27]1.45-5.45 [-6.27, -4.59]5.68 [4.74, 6.39]0% [0%, 0%]0%4%-1.38+0.362026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC1.44 [1.15, 1.72]0.94-1.06 [-1.70, -0.26]1.60 [1.29, 1.90]32% [13%, 54%]82%96%-0.49+0.072026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC1.44 [1.13, 1.77]0.94-1.06 [-1.76, -0.15]1.60 [1.27, 1.97]32% [13%, 57%]82%96%-0.49+0.072026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC1.44 [1.07, 1.75]0.94-1.06 [-1.75, 0.03]1.60 [1.22, 1.92]32% [11%, 61%]82%96%-0.49+0.072026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC1.44 [1.09, 1.75]0.94-1.06 [-1.74, -0.07]1.60 [1.24, 1.94]32% [12%, 57%]82%96%-0.49+0.072026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC1.42 [1.05, 1.80]0.84-1.22 [-1.76, -0.62]1.63 [1.23, 2.01]32% [18%, 46%]79%96%-0.47+0.172026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC1.42 [1.02, 1.91]0.84-1.22 [-1.90, -0.52]1.63 [1.20, 2.11]32% [16%, 50%]79%96%-0.47+0.172026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC1.42 [0.94, 1.87]0.84-1.22 [-1.87, -0.37]1.63 [1.15, 2.06]32% [15%, 50%]79%96%-0.47+0.172026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC1.42 [0.99, 1.86]0.84-1.22 [-1.86, -0.44]1.63 [1.18, 2.07]32% [16%, 50%]79%96%-0.47+0.172026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC1.52 [1.05, 1.99]0.86-1.38 [-1.99, -0.69]1.76 [1.26, 2.16]29% [10%, 50%]68%96%-0.58+0.162026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC1.52 [0.98, 2.08]0.86-1.38 [-2.07, -0.58]1.76 [1.22, 2.26]29% [8%, 52%]68%96%-0.58+0.162026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC1.52 [0.88, 2.05]0.86-1.38 [-2.05, -0.46]1.76 [1.15, 2.23]29% [6%, 56%]68%96%-0.58+0.162026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC1.52 [0.96, 2.05]0.86-1.38 [-2.05, -0.54]1.76 [1.15, 2.25]29% [8%, 55%]68%96%-0.58+0.162026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC1.59 [1.14, 2.05]0.79-1.55 [-2.04, -1.04]1.83 [1.35, 2.28]25% [7%, 46%]61%93%-0.65+0.222026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC1.59 [1.08, 2.18]0.79-1.55 [-2.18, -0.95]1.83 [1.30, 2.37]25% [7%, 50%]61%93%-0.65+0.222026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC1.59 [0.99, 2.16]0.79-1.55 [-2.16, -0.85]1.83 [1.23, 2.37]25% [6%, 56%]61%93%-0.65+0.222026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC1.59 [1.05, 2.18]0.79-1.55 [-2.18, -0.92]1.83 [1.29, 2.38]25% [6%, 52%]61%93%-0.65+0.222026-08-03 → 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 2, 00Z bilinear tmax+10+50-5-102026-08-03: -1.98 °F2026-08-04: -2.55 °F2026-08-05: -4.52 °F2026-08-06: -4.42 °F2026-08-07: -4.58 °F2026-08-08: -4.29 °F2026-08-09: -5.21 °F2026-08-10: -6 °F2026-08-11: -5.39 °F2026-08-12: -4.63 °F2026-08-13: -2.75 °F2026-08-14: -3.07 °F2026-08-15: -2.53 °F2026-08-16: -1.87 °F2026-08-17: -2.46 °F2026-08-18: -2.17 °F2026-08-19: -2.62 °F2026-08-20: -5.65 °F2026-08-21: -5.35 °F2026-08-22: -3.7 °F2026-08-23: -6.29 °F2026-08-24: -2.34 °F2026-08-25: -2.24 °F2026-08-26: -5.78 °F2026-08-27: -0.72 °F2026-08-28: -1.18 °F2026-08-29: -4.83 °F2026-08-30: -1.68 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.68
2026-08-29-4.83
2026-08-28-1.18
2026-08-27-0.72
2026-08-26-5.78
2026-08-25-2.24
2026-08-24-2.34
2026-08-23-6.29
2026-08-22-3.70
2026-08-21-5.35
2026-08-20-5.65
2026-08-19-2.62
2026-08-18-2.17
2026-08-17-2.46
2026-08-16-1.87
2026-08-15-2.53
2026-08-14-3.07
2026-08-13-2.75
2026-08-12-4.63
2026-08-11-5.39
2026-08-10-6.00
2026-08-09-5.21
2026-08-08-4.29
2026-08-07-4.58
2026-08-06-4.42
2026-08-05-4.52
2026-08-04-2.55
2026-08-03-1.98

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KSAN, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 6 days-5 to -4 °F: 6 days-4 to -3 °F: 2 days-3 to -2 °F: 8 days-2 to -1 °F: 4 days-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| 3.38 · P90 |e| 5.69 °F-100+10 °Fn = 28 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
-8.00-7.000
-7.00-6.001
-6.00-5.006
-5.00-4.006
-4.00-3.002
-3.00-2.008
-2.00-1.004
-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
2026-08283.60 -3.60

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28

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 (IFS init) 1 -2.17 [-2.17, -2.17] yes
FourCastNet v2 (IFS init) 1 +1.14 [1.14, 1.14] yes
NCEP GFS 28 +0.78 [-0.35, 1.95] no
GraphCast (IFS init) 26 -2.07 [-3.22, -1.23] yes
ECMWF IFS HRES 23 -2.30 [-2.83, -1.53] yes
Pangu-Weather (IFS init) 1 -3.17 [-3.17, -3.17] yes
Persistence (baseline) 28 +1.31 [-0.37, 2.57] no

Cite this page

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

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

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