Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

Los Angeles Intl · NCEP GFS · lead day 5

KLAX · gfs · lead 5

Target day = initialization date + 5 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, gfs-0p25, 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
tmax00Zbilinear30d25 2 QC1.56 [0.93, 2.23]1.61-0.54 [-1.78, 0.54]2.45 [1.54, 3.09]52% [29%, 74%]80%80%+0.45+0.372026-08-06 → 2026-08-30
tmax00Zbilinear90d25 2 QC1.56 [0.75, 2.24]1.61-0.54 [-1.93, 0.69]2.45 [1.08, 3.10]52% [25%, 80%]80%80%+0.45+0.372026-08-06 → 2026-08-30
tmax00Zbilinear365d25 2 QC1.56 [0.69, 2.32]1.61-0.54 [-2.18, 0.71]2.45 [1.00, 3.12]52% [22%, 80%]80%80%+0.45+0.372026-08-06 → 2026-08-30
tmax00Zbilinearall25 2 QC1.56 [0.78, 2.28]1.61-0.54 [-2.09, 0.65]2.45 [1.23, 3.12]52% [25%, 79%]80%80%+0.45+0.372026-08-06 → 2026-08-30
tmax00Znearest30d25 2 QC2.03 [1.30, 2.73]1.74-1.02 [-2.05, -0.01]2.70 [1.83, 3.43]36% [14%, 63%]68%80%+0.28+0.312026-08-06 → 2026-08-30
tmax00Znearest90d25 2 QC2.03 [1.08, 2.79]1.74-1.02 [-2.15, 0.03]2.70 [1.48, 3.43]36% [11%, 71%]68%80%+0.28+0.312026-08-06 → 2026-08-30
tmax00Znearest365d25 2 QC2.03 [1.14, 2.85]1.74-1.02 [-2.21, 0.13]2.70 [1.56, 3.52]36% [11%, 70%]68%80%+0.28+0.312026-08-06 → 2026-08-30
tmax00Znearestall25 2 QC2.03 [1.13, 2.86]1.74-1.02 [-2.31, 0.15]2.70 [1.57, 3.47]36% [12%, 68%]68%80%+0.28+0.312026-08-06 → 2026-08-30
tmax12Zbilinear30d25 2 QC1.80 [1.20, 2.47]1.74-0.65 [-1.96, 0.43]2.69 [1.65, 3.53]52% [41%, 62%]72%80%+0.37+0.312026-08-06 → 2026-08-30
tmax12Zbilinear90d25 2 QC1.80 [1.06, 2.57]1.74-0.65 [-2.20, 0.52]2.69 [1.38, 3.62]52% [38%, 63%]72%80%+0.37+0.312026-08-06 → 2026-08-30
tmax12Zbilinear365d25 2 QC1.80 [1.05, 2.57]1.74-0.65 [-2.54, 0.62]2.69 [1.24, 3.69]52% [36%, 64%]72%80%+0.37+0.312026-08-06 → 2026-08-30
tmax12Zbilinearall25 2 QC1.80 [1.05, 2.54]1.74-0.65 [-2.30, 0.47]2.69 [1.31, 3.60]52% [37%, 63%]72%80%+0.37+0.312026-08-06 → 2026-08-30
tmax12Znearest30d25 2 QC2.41 [1.52, 3.35]1.96-1.33 [-2.59, -0.28]3.17 [2.03, 4.18]24% [0%, 50%]48%80%+0.15+0.232026-08-06 → 2026-08-30
tmax12Znearest90d25 2 QC2.41 [1.34, 3.50]1.96-1.33 [-2.90, -0.25]3.17 [1.82, 4.28]24% [0%, 55%]48%80%+0.15+0.232026-08-06 → 2026-08-30
tmax12Znearest365d25 2 QC2.41 [1.33, 3.63]1.96-1.33 [-3.05, -0.12]3.17 [1.79, 4.45]24% [0%, 56%]48%80%+0.15+0.232026-08-06 → 2026-08-30
tmax12Znearestall25 2 QC2.41 [1.36, 3.46]1.96-1.33 [-2.90, -0.18]3.17 [1.77, 4.28]24% [0%, 57%]48%80%+0.15+0.232026-08-06 → 2026-08-30
tmin00Zbilinear30d25 2 QC3.57 [2.63, 4.61]1.42+3.57 [2.63, 4.61]4.00 [3.07, 4.90]12% [0%, 23%]16%32%-0.98+0.132026-08-06 → 2026-08-30
tmin00Zbilinear90d25 2 QC3.57 [2.60, 4.69]1.42+3.57 [2.60, 4.69]4.00 [2.94, 4.98]12% [0%, 24%]16%32%-0.98+0.132026-08-06 → 2026-08-30
tmin00Zbilinear365d25 2 QC3.57 [2.54, 4.81]1.42+3.57 [2.54, 4.81]4.00 [2.88, 5.12]12% [0%, 25%]16%32%-0.98+0.132026-08-06 → 2026-08-30
tmin00Zbilinearall25 2 QC3.57 [2.49, 4.83]1.42+3.57 [2.49, 4.83]4.00 [2.85, 5.10]12% [0%, 25%]16%32%-0.98+0.132026-08-06 → 2026-08-30
tmin00Znearest30d25 2 QC2.23 [1.45, 3.13]1.48+1.92 [0.93, 3.04]2.71 [1.71, 3.63]20% [4%, 41%]52%72%-0.24+0.092026-08-06 → 2026-08-30
tmin00Znearest90d25 2 QC2.23 [1.32, 3.23]1.48+1.92 [0.86, 3.18]2.71 [1.56, 3.71]20% [0%, 44%]52%72%-0.24+0.092026-08-06 → 2026-08-30
tmin00Znearest365d25 2 QC2.23 [1.34, 3.36]1.48+1.92 [0.78, 3.33]2.71 [1.52, 3.84]20% [0%, 46%]52%72%-0.24+0.092026-08-06 → 2026-08-30
tmin00Znearestall25 2 QC2.23 [1.28, 3.30]1.48+1.92 [0.75, 3.29]2.71 [1.50, 3.72]20% [0%, 46%]52%72%-0.24+0.092026-08-06 → 2026-08-30
tmin12Zbilinear30d25 2 QC3.53 [2.64, 4.44]1.41+3.42 [2.37, 4.43]3.87 [2.98, 4.68]4% [0%, 11%]20%36%-0.96+0.142026-08-06 → 2026-08-30
tmin12Zbilinear90d25 2 QC3.53 [2.61, 4.51]1.41+3.42 [2.32, 4.47]3.87 [2.90, 4.75]4% [0%, 12%]20%36%-0.96+0.142026-08-06 → 2026-08-30
tmin12Zbilinear365d25 2 QC3.53 [2.59, 4.60]1.41+3.42 [2.24, 4.59]3.87 [2.83, 4.80]4% [0%, 12%]20%36%-0.96+0.142026-08-06 → 2026-08-30
tmin12Zbilinearall25 2 QC3.53 [2.54, 4.59]1.41+3.42 [2.23, 4.59]3.87 [2.88, 4.81]4% [0%, 12%]20%36%-0.96+0.142026-08-06 → 2026-08-30
tmin12Znearest30d25 2 QC2.26 [1.45, 3.08]1.62+1.85 [0.71, 3.00]2.72 [1.85, 3.48]28% [12%, 50%]36%68%-0.26+0.012026-08-06 → 2026-08-30
tmin12Znearest90d25 2 QC2.26 [1.28, 3.19]1.62+1.85 [0.63, 3.10]2.72 [1.63, 3.56]28% [10%, 54%]36%68%-0.26+0.012026-08-06 → 2026-08-30
tmin12Znearest365d25 2 QC2.26 [1.25, 3.28]1.62+1.85 [0.57, 3.17]2.72 [1.63, 3.70]28% [8%, 56%]36%68%-0.26+0.012026-08-06 → 2026-08-30
tmin12Znearestall25 2 QC2.26 [1.23, 3.23]1.62+1.85 [0.61, 3.21]2.72 [1.57, 3.61]28% [7%, 59%]36%68%-0.26+0.012026-08-06 → 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 NCEP GFS at KLAX, lead day 5, 00Z bilinear tmax+10+50-5-102026-08-06: -0 °F2026-08-07: +0.13 °F2026-08-08: +0.53 °F2026-08-09: +0.77 °F2026-08-10: +1.21 °F2026-08-11: +0.74 °F2026-08-12: +0.35 °F2026-08-13: -1.11 °F2026-08-14: -4.98 °F2026-08-15: -1.59 °F2026-08-16: -0.16 °F2026-08-17: +1.16 °F2026-08-18: -0.42 °F2026-08-19: -0.23 °F2026-08-20: +6.95 °F2026-08-21: -0.3 °F2026-08-22: +0.46 °F2026-08-23: -1.71 °F2026-08-24: +0.41 °F2026-08-25: -0.12 °F2026-08-26: -3.46 °F2026-08-27: -6.32 °F2026-08-28: -1.44 °F2026-08-29: -1.25 °F2026-08-30: -3.12 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.12
2026-08-29-1.25
2026-08-28-1.44
2026-08-27-6.32
2026-08-26-3.46
2026-08-25-0.12
2026-08-24+0.41
2026-08-23-1.71
2026-08-22+0.46
2026-08-21-0.30
2026-08-20+6.95
2026-08-19-0.23
2026-08-18-0.42
2026-08-17+1.16
2026-08-16-0.16
2026-08-15-1.59
2026-08-14-4.98
2026-08-13-1.11
2026-08-12+0.35
2026-08-11+0.74
2026-08-10+1.21
2026-08-09+0.77
2026-08-08+0.53
2026-08-07+0.13
2026-08-06-0.00

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAX, lead day 5-10 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: 0 days-5 to -4 °F: 1 day-4 to -3 °F: 2 days-3 to -2 °F: 0 days-2 to -1 °F: 5 days-1 to 0 °F: 6 days0 to 1 °F: 7 days1 to 2 °F: 2 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 1 day7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 0.77 · P90 |e| 4.38 °F-100+10 °Fn = 25 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
-6.00-5.000
-5.00-4.001
-4.00-3.002
-3.00-2.000
-2.00-1.005
-1.00+0.006
+0.00+1.007
+1.00+2.002
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.001
+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
2026-08251.56 -0.54

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25
NCEP GFS2026-08-06 → 2026-08-30 25

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 25 -0.49 [-1.24, 0.36] no
GraphCast (IFS init) 25 -2.21 [-3.14, -1.35] yes
ECMWF IFS HRES 18 -0.57 [-1.53, 0.44] no
Persistence (baseline) 25 -1.28 [-2.06, -0.47] yes

Cite this page

ShortCastCheck, KLAX gfs lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAX/model/gfs/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), model gfs, lead day 5. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KLAX/model/gfs/lead/5/

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