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

Los Angeles Intl · ECMWF IFS HRES · lead day 4

KLAX · ifs_hres · lead 4

Target day = initialization date + 4 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, ifs-gpid161, 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
tmax00Zbilinear30d20 2 QC1.97 [1.36, 2.43]1.42-1.31 [-1.84, -0.71]2.39 [1.76, 2.81]30% [16%, 50%]55%70%+0.27+0.462026-08-05 → 2026-08-30
tmax00Zbilinear90d20 2 QC1.97 [1.01, 2.47]1.42-1.31 [-1.85, -0.47]2.39 [1.40, 2.84]30% [14%, 61%]55%70%+0.27+0.462026-08-05 → 2026-08-30
tmax00Zbilinear365d20 2 QC1.97 [1.10, 2.50]1.42-1.31 [-1.92, -0.47]2.39 [1.38, 2.85]30% [13%, 57%]55%70%+0.27+0.462026-08-05 → 2026-08-30
tmax00Zbilinearall20 2 QC1.97 [1.00, 2.48]1.42-1.31 [-1.93, -0.41]2.39 [1.31, 2.84]30% [14%, 62%]55%70%+0.27+0.462026-08-05 → 2026-08-30
tmax00Znearest30d20 2 QC4.72 [4.20, 5.20]1.37-4.72 [-5.20, -4.20]5.05 [4.43, 5.53]10% [0%, 18%]10%10%-0.75+0.472026-08-05 → 2026-08-30
tmax00Znearest90d20 2 QC4.72 [4.13, 5.19]1.37-4.72 [-5.19, -4.13]5.05 [4.33, 5.52]10% [0%, 18%]10%10%-0.75+0.472026-08-05 → 2026-08-30
tmax00Znearest365d20 2 QC4.72 [4.13, 5.22]1.37-4.72 [-5.22, -4.13]5.05 [4.33, 5.57]10% [0%, 18%]10%10%-0.75+0.472026-08-05 → 2026-08-30
tmax00Znearestall20 2 QC4.72 [4.17, 5.25]1.37-4.72 [-5.25, -4.17]5.05 [4.33, 5.57]10% [0%, 18%]10%10%-0.75+0.472026-08-05 → 2026-08-30
tmax12Zbilinear30d21 2 QC2.31 [1.62, 2.78]1.58-1.54 [-2.08, -0.93]2.61 [2.03, 3.02]14% [5%, 33%]48%67%+0.15+0.412026-08-05 → 2026-08-30
tmax12Zbilinear90d21 2 QC2.31 [1.43, 2.86]1.58-1.54 [-2.14, -0.69]2.61 [1.86, 3.06]14% [3%, 43%]48%67%+0.15+0.412026-08-05 → 2026-08-30
tmax12Zbilinear365d21 2 QC2.31 [1.46, 2.86]1.58-1.54 [-2.15, -0.75]2.61 [1.83, 3.07]14% [0%, 38%]48%67%+0.15+0.412026-08-05 → 2026-08-30
tmax12Zbilinearall21 2 QC2.31 [1.45, 2.86]1.58-1.54 [-2.19, -0.69]2.61 [1.80, 3.09]14% [0%, 40%]48%67%+0.15+0.412026-08-05 → 2026-08-30
tmax12Znearest30d21 2 QC4.83 [4.32, 5.35]1.58-4.78 [-5.32, -4.24]5.21 [4.70, 5.63]10% [0%, 20%]14%14%-0.78+0.412026-08-05 → 2026-08-30
tmax12Znearest90d21 2 QC4.83 [4.15, 5.35]1.58-4.78 [-5.31, -4.10]5.21 [4.47, 5.64]10% [0%, 21%]14%14%-0.78+0.412026-08-05 → 2026-08-30
tmax12Znearest365d21 2 QC4.83 [4.22, 5.41]1.58-4.78 [-5.37, -4.12]5.21 [4.55, 5.66]10% [0%, 22%]14%14%-0.78+0.412026-08-05 → 2026-08-30
tmax12Znearestall21 2 QC4.83 [4.13, 5.43]1.58-4.78 [-5.35, -4.12]5.21 [4.48, 5.68]10% [0%, 20%]14%14%-0.78+0.412026-08-05 → 2026-08-30
tmin00Zbilinear30d20 2 QC1.36 [0.61, 2.11]1.09+1.26 [0.47, 2.09]1.86 [0.76, 2.65]50% [25%, 80%]75%95%+0.15+0.272026-08-05 → 2026-08-30
tmin00Zbilinear90d20 2 QC1.36 [0.52, 2.23]1.09+1.26 [0.43, 2.18]1.86 [0.67, 2.82]50% [25%, 85%]75%95%+0.15+0.272026-08-05 → 2026-08-30
tmin00Zbilinear365d20 2 QC1.36 [0.56, 2.30]1.09+1.26 [0.43, 2.27]1.86 [0.69, 2.82]50% [22%, 86%]75%95%+0.15+0.272026-08-05 → 2026-08-30
tmin00Zbilinearall20 2 QC1.36 [0.46, 2.20]1.09+1.26 [0.38, 2.15]1.86 [0.56, 2.75]50% [23%, 94%]75%95%+0.15+0.272026-08-05 → 2026-08-30
tmin00Znearest30d20 2 QC1.17 [0.58, 1.80]1.21+0.52 [-0.47, 1.29]1.47 [0.69, 2.01]50% [20%, 89%]75%100%+0.27+0.192026-08-05 → 2026-08-30
tmin00Znearest90d20 2 QC1.17 [0.51, 1.95]1.21+0.52 [-0.56, 1.38]1.47 [0.56, 2.13]50% [12%, 100%]75%100%+0.27+0.192026-08-05 → 2026-08-30
tmin00Znearest365d20 2 QC1.17 [0.50, 2.04]1.21+0.52 [-0.55, 1.42]1.47 [0.56, 2.16]50% [7%, 100%]75%100%+0.27+0.192026-08-05 → 2026-08-30
tmin00Znearestall20 2 QC1.17 [0.49, 1.93]1.21+0.52 [-0.56, 1.40]1.47 [0.56, 2.13]50% [10%, 100%]75%100%+0.27+0.192026-08-05 → 2026-08-30
tmin12Zbilinear30d21 2 QC1.36 [0.65, 2.19]1.14+1.21 [0.32, 2.17]1.97 [0.78, 2.92]52% [25%, 82%]76%90%+0.16+0.282026-08-05 → 2026-08-30
tmin12Zbilinear90d21 2 QC1.36 [0.56, 2.39]1.14+1.21 [0.33, 2.39]1.97 [0.68, 3.14]52% [25%, 86%]76%90%+0.16+0.282026-08-05 → 2026-08-30
tmin12Zbilinear365d21 2 QC1.36 [0.57, 2.45]1.14+1.21 [0.32, 2.45]1.97 [0.67, 3.17]52% [22%, 88%]76%90%+0.16+0.282026-08-05 → 2026-08-30
tmin12Zbilinearall21 2 QC1.36 [0.50, 2.37]1.14+1.21 [0.23, 2.37]1.97 [0.58, 3.06]52% [23%, 95%]76%90%+0.16+0.282026-08-05 → 2026-08-30
tmin12Znearest30d21 2 QC1.33 [0.77, 2.10]1.34+0.51 [-0.50, 1.56]1.86 [0.90, 2.78]48% [28%, 71%]76%95%+0.18+0.152026-08-05 → 2026-08-30
tmin12Znearest90d21 2 QC1.33 [0.67, 2.29]1.34+0.51 [-0.66, 1.72]1.86 [0.77, 2.96]48% [25%, 82%]76%95%+0.18+0.152026-08-05 → 2026-08-30
tmin12Znearest365d21 2 QC1.33 [0.67, 2.36]1.34+0.51 [-0.63, 1.80]1.86 [0.73, 2.99]48% [20%, 87%]76%95%+0.18+0.152026-08-05 → 2026-08-30
tmin12Znearestall21 2 QC1.33 [0.67, 2.24]1.34+0.51 [-0.66, 1.61]1.86 [0.70, 2.91]48% [23%, 85%]76%95%+0.18+0.152026-08-05 → 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 IFS HRES at KLAX, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -0.3 °F2026-08-11: -0.65 °F2026-08-12: -1.27 °F2026-08-13: -1.09 °F2026-08-14: -3.49 °F2026-08-16: -0.87 °F2026-08-17: -0.47 °F2026-08-18: -5.07 °F2026-08-19: -2.14 °F2026-08-20: +2.93 °F2026-08-21: -1.15 °F2026-08-22: -3.23 °F2026-08-23: -3.7 °F2026-08-24: -2.15 °F2026-08-25: -0.54 °F2026-08-26: -1.22 °F2026-08-27: -0.66 °F2026-08-28: +3.69 °F2026-08-29: -1.64 °F2026-08-30: -3.23 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.23
2026-08-29-1.64
2026-08-28+3.69
2026-08-27-0.66
2026-08-26-1.22
2026-08-25-0.54
2026-08-24-2.15
2026-08-23-3.70
2026-08-22-3.23
2026-08-21-1.15
2026-08-20+2.93
2026-08-19-2.14
2026-08-18-5.07
2026-08-17-0.47
2026-08-16-0.87
2026-08-15—
2026-08-14-3.49
2026-08-13-1.09
2026-08-12-1.27
2026-08-11-0.65
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05-0.30

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KLAX, lead day 4-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 0 days-4 to -3 °F: 4 days-3 to -2 °F: 2 days-2 to -1 °F: 5 days-1 to 0 °F: 6 days0 to 1 °F: 0 days1 to 2 °F: 0 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 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| 1.46 · P90 |e| 3.69 °F-100+10 °Fn = 20 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
-7.00-6.000
-6.00-5.001
-5.00-4.000
-4.00-3.004
-3.00-2.002
-2.00-1.005
-1.00+0.006
+0.00+1.000
+1.00+2.000
+2.00+3.001
+3.00+4.001
+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
2026-08201.97 -1.31

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 21
ECMWF IFS HRES2026-08-05 → 2026-08-30 21

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 20 +0.34 [-0.53, 0.94] no
NCEP GFS 20 -0.44 [-1.81, 0.56] no
GraphCast (IFS init) 19 -2.16 [-3.67, -1.17] yes
Persistence (baseline) 20 -0.73 [-1.96, 0.08] no

Cite this page

ShortCastCheck, KLAX ifs_hres lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAX/model/ifs_hres/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), model ifs_hres, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KLAX/model/ifs_hres/lead/4/

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