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

Los Angeles Intl · ECMWF AIFS Single · lead day 8

KLAX · 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, 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
tmax00Zbilinear30d22 2 QC1.87 [1.04, 2.71]1.85-0.57 [-2.15, 0.70]2.53 [1.43, 3.47]36% [16%, 63%]64%77%+0.44+0.412026-08-09 → 2026-08-30
tmax00Zbilinear90d22 2 QC1.87 [0.84, 2.85]1.85-0.57 [-2.44, 0.77]2.53 [1.08, 3.60]36% [14%, 71%]64%77%+0.44+0.412026-08-09 → 2026-08-30
tmax00Zbilinear365d22 2 QC1.87 [0.82, 2.91]1.85-0.57 [-2.52, 0.85]2.53 [1.06, 3.70]36% [14%, 71%]64%77%+0.44+0.412026-08-09 → 2026-08-30
tmax00Zbilinearall22 2 QC1.87 [0.84, 2.91]1.85-0.57 [-2.50, 0.74]2.53 [1.08, 3.66]36% [13%, 71%]64%77%+0.44+0.412026-08-09 → 2026-08-30
tmax00Znearest30d22 2 QC2.00 [1.00, 3.12]1.86-1.14 [-2.82, 0.19]2.76 [1.41, 3.95]41% [17%, 73%]64%77%+0.41+0.412026-08-09 → 2026-08-30
tmax00Znearest90d22 2 QC2.00 [0.78, 3.32]1.86-1.14 [-3.16, 0.27]2.76 [1.17, 4.12]41% [15%, 88%]64%77%+0.41+0.412026-08-09 → 2026-08-30
tmax00Znearest365d22 2 QC2.00 [0.71, 3.33]1.86-1.14 [-3.30, 0.35]2.76 [1.09, 4.19]41% [14%, 88%]64%77%+0.41+0.412026-08-09 → 2026-08-30
tmax00Znearestall22 2 QC2.00 [0.75, 3.34]1.86-1.14 [-3.27, 0.24]2.76 [1.08, 4.19]41% [14%, 83%]64%77%+0.41+0.412026-08-09 → 2026-08-30
tmax12Zbilinear30d22 2 QC2.01 [1.16, 2.75]1.97-0.32 [-1.39, 0.86]2.78 [1.46, 3.56]50% [26%, 78%]59%77%+0.40+0.382026-08-09 → 2026-08-30
tmax12Zbilinear90d22 2 QC2.01 [0.97, 2.79]1.97-0.32 [-1.46, 1.10]2.78 [1.15, 3.63]50% [25%, 88%]59%77%+0.40+0.382026-08-09 → 2026-08-30
tmax12Zbilinear365d22 2 QC2.01 [0.94, 2.87]1.97-0.32 [-1.50, 1.32]2.78 [1.12, 3.64]50% [21%, 88%]59%77%+0.40+0.382026-08-09 → 2026-08-30
tmax12Zbilinearall22 2 QC2.01 [0.98, 2.87]1.97-0.32 [-1.47, 1.11]2.78 [1.15, 3.66]50% [23%, 86%]59%77%+0.40+0.382026-08-09 → 2026-08-30
tmax12Znearest30d22 2 QC2.17 [1.34, 2.97]1.93-0.87 [-2.00, 0.30]2.85 [1.56, 3.72]27% [14%, 44%]68%77%+0.35+0.392026-08-09 → 2026-08-30
tmax12Znearest90d22 2 QC2.17 [1.18, 3.02]1.93-0.87 [-2.09, 0.54]2.85 [1.41, 3.79]27% [14%, 50%]68%77%+0.35+0.392026-08-09 → 2026-08-30
tmax12Znearest365d22 2 QC2.17 [1.19, 3.06]1.93-0.87 [-2.13, 0.61]2.85 [1.38, 3.82]27% [14%, 50%]68%77%+0.35+0.392026-08-09 → 2026-08-30
tmax12Znearestall22 2 QC2.17 [1.19, 3.10]1.93-0.87 [-2.10, 0.55]2.85 [1.42, 3.82]27% [14%, 50%]68%77%+0.35+0.392026-08-09 → 2026-08-30
tmin00Zbilinear30d22 2 QC1.19 [0.84, 1.61]1.12-0.35 [-0.75, 0.05]1.42 [0.94, 1.83]41% [30%, 53%]82%100%+0.48+0.442026-08-09 → 2026-08-30
tmin00Zbilinear90d22 2 QC1.19 [0.84, 1.63]1.12-0.35 [-0.83, 0.10]1.42 [0.93, 1.85]41% [29%, 55%]82%100%+0.48+0.442026-08-09 → 2026-08-30
tmin00Zbilinear365d22 2 QC1.19 [0.84, 1.65]1.12-0.35 [-0.89, 0.08]1.42 [0.93, 1.88]41% [29%, 56%]82%100%+0.48+0.442026-08-09 → 2026-08-30
tmin00Zbilinearall22 2 QC1.19 [0.84, 1.65]1.12-0.35 [-0.85, 0.16]1.42 [0.93, 1.88]41% [29%, 54%]82%100%+0.48+0.442026-08-09 → 2026-08-30
tmin00Znearest30d22 2 QC1.20 [0.89, 1.56]1.10-0.38 [-0.74, 0.04]1.40 [1.00, 1.77]41% [30%, 53%]82%100%+0.48+0.452026-08-09 → 2026-08-30
tmin00Znearest90d22 2 QC1.20 [0.89, 1.60]1.10-0.38 [-0.79, 0.07]1.40 [0.99, 1.80]41% [29%, 55%]82%100%+0.48+0.452026-08-09 → 2026-08-30
tmin00Znearest365d22 2 QC1.20 [0.88, 1.60]1.10-0.38 [-0.88, 0.06]1.40 [0.98, 1.81]41% [29%, 56%]82%100%+0.48+0.452026-08-09 → 2026-08-30
tmin00Znearestall22 2 QC1.20 [0.88, 1.61]1.10-0.38 [-0.84, 0.10]1.40 [0.98, 1.80]41% [29%, 54%]82%100%+0.48+0.452026-08-09 → 2026-08-30
tmin12Zbilinear30d22 2 QC1.35 [0.93, 1.90]1.18-0.64 [-1.08, -0.11]1.60 [1.09, 2.13]36% [19%, 54%]77%95%+0.42+0.412026-08-09 → 2026-08-30
tmin12Zbilinear90d22 2 QC1.35 [0.90, 1.98]1.18-0.64 [-1.09, -0.08]1.60 [1.04, 2.20]36% [17%, 56%]77%95%+0.42+0.412026-08-09 → 2026-08-30
tmin12Zbilinear365d22 2 QC1.35 [0.89, 2.00]1.18-0.64 [-1.08, -0.04]1.60 [1.03, 2.25]36% [15%, 57%]77%95%+0.42+0.412026-08-09 → 2026-08-30
tmin12Zbilinearall22 2 QC1.35 [0.88, 2.04]1.18-0.64 [-1.08, 0.04]1.60 [1.03, 2.24]36% [14%, 57%]77%95%+0.42+0.412026-08-09 → 2026-08-30
tmin12Znearest30d22 2 QC1.40 [1.02, 1.89]1.22-0.63 [-1.08, -0.03]1.63 [1.19, 2.10]32% [18%, 47%]73%95%+0.40+0.392026-08-09 → 2026-08-30
tmin12Znearest90d22 2 QC1.40 [0.98, 1.98]1.22-0.63 [-1.09, 0.03]1.63 [1.15, 2.17]32% [17%, 50%]73%95%+0.40+0.392026-08-09 → 2026-08-30
tmin12Znearest365d22 2 QC1.40 [0.97, 2.00]1.22-0.63 [-1.08, 0.03]1.63 [1.13, 2.19]32% [15%, 50%]73%95%+0.40+0.392026-08-09 → 2026-08-30
tmin12Znearestall22 2 QC1.40 [0.97, 2.02]1.22-0.63 [-1.09, 0.10]1.63 [1.13, 2.20]32% [14%, 50%]73%95%+0.40+0.392026-08-09 → 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 KLAX, lead day 8, 00Z bilinear tmax+10+50-5-102026-08-09: +0.2 °F2026-08-10: +0.39 °F2026-08-11: -0.31 °F2026-08-12: +1.26 °F2026-08-13: +0.76 °F2026-08-14: -2.29 °F2026-08-15: -0.7 °F2026-08-16: +3.69 °F2026-08-17: -0.41 °F2026-08-18: +1.91 °F2026-08-19: +1.17 °F2026-08-20: +3.23 °F2026-08-21: -0.72 °F2026-08-22: -1.01 °F2026-08-23: -1.22 °F2026-08-24: -3.37 °F2026-08-25: -2.45 °F2026-08-26: -2.92 °F2026-08-27: -7.62 °F2026-08-28: +0.28 °F2026-08-29: -3.77 °F2026-08-30: +1.4 °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+1.40
2026-08-29-3.77
2026-08-28+0.28
2026-08-27-7.62
2026-08-26-2.92
2026-08-25-2.45
2026-08-24-3.37
2026-08-23-1.22
2026-08-22-1.01
2026-08-21-0.72
2026-08-20+3.23
2026-08-19+1.17
2026-08-18+1.91
2026-08-17-0.41
2026-08-16+3.69
2026-08-15-0.70
2026-08-14-2.29
2026-08-13+0.76
2026-08-12+1.26
2026-08-11-0.31
2026-08-10+0.39
2026-08-09+0.20

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KLAX, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 0 days-4 to -3 °F: 2 days-3 to -2 °F: 3 days-2 to -1 °F: 2 days-1 to 0 °F: 4 days0 to 1 °F: 4 days1 to 2 °F: 4 days2 to 3 °F: 0 days3 to 4 °F: 2 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| 1.24 · P90 |e| 3.66 °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
-9.00-8.000
-8.00-7.001
-7.00-6.000
-6.00-5.000
-5.00-4.000
-4.00-3.002
-3.00-2.003
-2.00-1.002
-1.00+0.004
+0.00+1.004
+1.00+2.004
+2.00+3.000
+3.00+4.002
+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
2026-08221.87 -0.57

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 -1.12 [-1.86, -0.58] yes
GraphCast (IFS init) 22 -3.03 [-4.76, -1.45] yes
ECMWF IFS HRES 17 -1.22 [-3.05, 0.97] no
Persistence (baseline) 22 -1.50 [-3.24, 0.25] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), 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/KLAX/model/aifs_single/lead/8/

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

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