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

Los Angeles Intl · ECMWF AIFS Single · lead day 3

KLAX · aifs_single · lead 3

Target day = initialization date + 3 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, 2 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
tmax00Zbilinear30d27 2 QC1.70 [1.22, 2.18]1.37+1.26 [0.67, 1.78]2.16 [1.51, 2.66]37% [21%, 55%]67%85%+0.22+0.382026-08-04 → 2026-08-30
tmax00Zbilinear90d27 2 QC1.70 [1.19, 2.20]1.37+1.26 [0.48, 1.77]2.16 [1.39, 2.69]37% [20%, 57%]67%85%+0.22+0.382026-08-04 → 2026-08-30
tmax00Zbilinear365d27 2 QC1.70 [1.15, 2.24]1.37+1.26 [0.44, 1.82]2.16 [1.39, 2.68]37% [19%, 58%]67%85%+0.22+0.382026-08-04 → 2026-08-30
tmax00Zbilinearall27 2 QC1.70 [1.15, 2.25]1.37+1.26 [0.52, 1.73]2.16 [1.35, 2.71]37% [20%, 58%]67%85%+0.22+0.382026-08-04 → 2026-08-30
tmax00Znearest30d27 2 QC1.53 [1.10, 1.97]1.37+0.77 [0.14, 1.29]1.94 [1.34, 2.42]37% [23%, 52%]78%81%+0.30+0.382026-08-04 → 2026-08-30
tmax00Znearest90d27 2 QC1.53 [0.99, 2.02]1.37+0.77 [-0.07, 1.30]1.94 [1.12, 2.46]37% [22%, 52%]78%81%+0.30+0.382026-08-04 → 2026-08-30
tmax00Znearest365d27 2 QC1.53 [1.02, 2.06]1.37+0.77 [-0.08, 1.33]1.94 [1.15, 2.49]37% [20%, 53%]78%81%+0.30+0.382026-08-04 → 2026-08-30
tmax00Znearestall27 2 QC1.53 [1.00, 2.07]1.37+0.77 [-0.05, 1.28]1.94 [1.14, 2.52]37% [20%, 52%]78%81%+0.30+0.382026-08-04 → 2026-08-30
tmax12Zbilinear30d27 2 QC1.41 [0.86, 1.97]1.40+0.67 [-0.08, 1.34]1.95 [1.23, 2.48]59% [42%, 77%]70%81%+0.35+0.372026-08-04 → 2026-08-30
tmax12Zbilinear90d27 2 QC1.41 [0.70, 2.00]1.40+0.67 [-0.32, 1.35]1.95 [0.88, 2.53]59% [39%, 80%]70%81%+0.35+0.372026-08-04 → 2026-08-30
tmax12Zbilinear365d27 2 QC1.41 [0.68, 2.08]1.40+0.67 [-0.27, 1.40]1.95 [0.90, 2.57]59% [36%, 80%]70%81%+0.35+0.372026-08-04 → 2026-08-30
tmax12Zbilinearall27 2 QC1.41 [0.68, 2.09]1.40+0.67 [-0.31, 1.31]1.95 [0.88, 2.59]59% [36%, 80%]70%81%+0.35+0.372026-08-04 → 2026-08-30
tmax12Znearest30d27 2 QC1.38 [0.92, 1.84]1.40+0.17 [-0.59, 0.83]1.87 [1.18, 2.37]52% [37%, 71%]78%85%+0.37+0.372026-08-04 → 2026-08-30
tmax12Znearest90d27 2 QC1.38 [0.78, 1.92]1.40+0.17 [-0.84, 0.86]1.87 [0.87, 2.47]52% [35%, 75%]78%85%+0.37+0.372026-08-04 → 2026-08-30
tmax12Znearest365d27 2 QC1.38 [0.75, 1.96]1.40+0.17 [-0.81, 0.91]1.87 [0.84, 2.50]52% [33%, 75%]78%85%+0.37+0.372026-08-04 → 2026-08-30
tmax12Znearestall27 2 QC1.38 [0.79, 1.97]1.40+0.17 [-0.83, 0.84]1.87 [0.90, 2.49]52% [33%, 75%]78%85%+0.37+0.372026-08-04 → 2026-08-30
tmin00Zbilinear30d27 2 QC0.68 [0.46, 0.96]0.69+0.07 [-0.30, 0.53]0.87 [0.56, 1.17]74% [50%, 93%]96%100%+0.54+0.502026-08-04 → 2026-08-30
tmin00Zbilinear90d27 2 QC0.68 [0.45, 0.98]0.69+0.07 [-0.34, 0.55]0.87 [0.54, 1.19]74% [50%, 95%]96%100%+0.54+0.502026-08-04 → 2026-08-30
tmin00Zbilinear365d27 2 QC0.68 [0.44, 1.02]0.69+0.07 [-0.33, 0.63]0.87 [0.52, 1.21]74% [46%, 96%]96%100%+0.54+0.502026-08-04 → 2026-08-30
tmin00Zbilinearall27 2 QC0.68 [0.44, 0.99]0.69+0.07 [-0.36, 0.64]0.87 [0.51, 1.19]74% [47%, 100%]96%100%+0.54+0.502026-08-04 → 2026-08-30
tmin00Znearest30d27 2 QC0.74 [0.50, 1.10]0.76+0.09 [-0.38, 0.67]0.97 [0.62, 1.33]74% [50%, 93%]96%100%+0.50+0.452026-08-04 → 2026-08-30
tmin00Znearest90d27 2 QC0.74 [0.49, 1.12]0.76+0.09 [-0.42, 0.71]0.97 [0.59, 1.36]74% [50%, 95%]96%100%+0.50+0.452026-08-04 → 2026-08-30
tmin00Znearest365d27 2 QC0.74 [0.47, 1.17]0.76+0.09 [-0.41, 0.79]0.97 [0.58, 1.38]74% [46%, 96%]96%100%+0.50+0.452026-08-04 → 2026-08-30
tmin00Znearestall27 2 QC0.74 [0.48, 1.15]0.76+0.09 [-0.45, 0.79]0.97 [0.57, 1.38]74% [47%, 100%]96%100%+0.50+0.452026-08-04 → 2026-08-30
tmin12Zbilinear30d27 2 QC0.70 [0.59, 0.84]0.60-0.31 [-0.68, 0.08]0.81 [0.68, 0.94]74% [58%, 89%]100%100%+0.53+0.562026-08-04 → 2026-08-30
tmin12Zbilinear90d27 2 QC0.70 [0.59, 0.85]0.60-0.31 [-0.76, 0.10]0.81 [0.69, 0.96]74% [56%, 87%]100%100%+0.53+0.562026-08-04 → 2026-08-30
tmin12Zbilinear365d27 2 QC0.70 [0.58, 0.86]0.60-0.31 [-0.75, 0.15]0.81 [0.68, 0.96]74% [56%, 90%]100%100%+0.53+0.562026-08-04 → 2026-08-30
tmin12Zbilinearall27 2 QC0.70 [0.58, 0.87]0.60-0.31 [-0.77, 0.15]0.81 [0.68, 0.97]74% [55%, 89%]100%100%+0.53+0.562026-08-04 → 2026-08-30
tmin12Znearest30d27 2 QC0.79 [0.68, 0.94]0.69-0.32 [-0.79, 0.19]0.91 [0.80, 1.02]63% [52%, 73%]100%100%+0.47+0.502026-08-04 → 2026-08-30
tmin12Znearest90d27 2 QC0.79 [0.67, 0.95]0.69-0.32 [-0.88, 0.24]0.91 [0.80, 1.04]63% [50%, 72%]100%100%+0.47+0.502026-08-04 → 2026-08-30
tmin12Znearest365d27 2 QC0.79 [0.66, 0.94]0.69-0.32 [-0.87, 0.29]0.91 [0.78, 1.04]63% [50%, 72%]100%100%+0.47+0.502026-08-04 → 2026-08-30
tmin12Znearestall27 2 QC0.79 [0.67, 0.96]0.69-0.32 [-0.88, 0.29]0.91 [0.79, 1.05]63% [48%, 73%]100%100%+0.47+0.502026-08-04 → 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 KLAX, lead day 3, 00Z bilinear tmax+5+2.50-2.5-52026-08-04: +0.83 °F2026-08-05: +1.44 °F2026-08-06: +1.44 °F2026-08-07: +1.19 °F2026-08-08: +2.47 °F2026-08-09: +0.81 °F2026-08-10: +1.87 °F2026-08-11: -0.28 °F2026-08-12: +0.15 °F2026-08-13: +0.29 °F2026-08-14: -0.47 °F2026-08-15: +1.92 °F2026-08-16: +3.72 °F2026-08-17: +3.76 °F2026-08-18: +0.24 °F2026-08-19: +0.58 °F2026-08-20: +4.8 °F2026-08-21: -1.31 °F2026-08-22: +1.54 °F2026-08-23: -0.15 °F2026-08-24: +2.44 °F2026-08-25: +4.77 °F2026-08-26: +2.45 °F2026-08-27: +2.25 °F2026-08-28: +1.03 °F2026-08-29: -2.9 °F2026-08-30: -0.82 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-0.82
2026-08-29-2.90
2026-08-28+1.03
2026-08-27+2.25
2026-08-26+2.45
2026-08-25+4.77
2026-08-24+2.44
2026-08-23-0.15
2026-08-22+1.54
2026-08-21-1.31
2026-08-20+4.80
2026-08-19+0.58
2026-08-18+0.24
2026-08-17+3.76
2026-08-16+3.72
2026-08-15+1.92
2026-08-14-0.47
2026-08-13+0.29
2026-08-12+0.15
2026-08-11-0.28
2026-08-10+1.87
2026-08-09+0.81
2026-08-08+2.47
2026-08-07+1.19
2026-08-06+1.44
2026-08-05+1.44
2026-08-04+0.83

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KLAX, lead day 3-5 to -4.5 °F: 0 days-4.5 to -4 °F: 0 days-4 to -3.5 °F: 0 days-3.5 to -3 °F: 0 days-3 to -2.5 °F: 1 day-2.5 to -2 °F: 0 days-2 to -1.5 °F: 0 days-1.5 to -1 °F: 1 day-1 to -0.5 °F: 1 day-0.5 to 0 °F: 3 days0 to 0.5 °F: 3 days0.5 to 1 °F: 3 days1 to 1.5 °F: 4 days1.5 to 2 °F: 3 days2 to 2.5 °F: 4 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 2 days4 to 4.5 °F: 0 days4.5 to 5 °F: 2 daysdashed: P50 |e| 1.44 · P90 |e| 3.74 °F-50+5 °Fn = 27 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
-5.00-4.500
-4.50-4.000
-4.00-3.500
-3.50-3.000
-3.00-2.501
-2.50-2.000
-2.00-1.500
-1.50-1.001
-1.00-0.501
-0.50+0.003
+0.00+0.503
+0.50+1.003
+1.00+1.504
+1.50+2.003
+2.00+2.504
+2.50+3.000
+3.00+3.500
+3.50+4.002
+4.00+4.500
+4.50+5.002

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08271.70 +1.26

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27

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 27 -0.41 [-1.11, 0.14] no
GraphCast (IFS init) 25 -1.97 [-2.72, -1.44] yes
ECMWF IFS HRES 22 -0.46 [-1.32, 0.60] no
Persistence (baseline) 27 -0.49 [-1.19, 0.08] no

Cite this page

ShortCastCheck, KLAX aifs_single lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAX/model/aifs_single/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), model aifs_single, lead day 3. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KLAX/model/aifs_single/lead/3/

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