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 7

KLAX · gfs · lead 7

Target day = initialization date + 7 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
tmax00Zbilinear30d23 2 QC1.98 [0.81, 3.33]1.95-1.17 [-2.57, -0.19]2.90 [1.17, 4.38]39% [11%, 69%]65%78%+0.40+0.352026-08-08 → 2026-08-30
tmax00Zbilinear90d23 2 QC1.98 [0.72, 3.44]1.95-1.17 [-2.75, -0.10]2.90 [1.10, 4.46]39% [7%, 75%]65%78%+0.40+0.352026-08-08 → 2026-08-30
tmax00Zbilinear365d23 2 QC1.98 [0.70, 3.52]1.95-1.17 [-2.86, -0.10]2.90 [1.04, 4.52]39% [5%, 75%]65%78%+0.40+0.352026-08-08 → 2026-08-30
tmax00Zbilinearall23 2 QC1.98 [0.72, 3.57]1.95-1.17 [-2.82, -0.10]2.90 [1.03, 4.60]39% [0%, 76%]65%78%+0.40+0.352026-08-08 → 2026-08-30
tmax00Znearest30d23 2 QC2.38 [1.49, 3.57]1.94-1.81 [-3.16, -0.93]3.30 [1.74, 4.93]22% [13%, 33%]57%74%+0.28+0.352026-08-08 → 2026-08-30
tmax00Znearest90d23 2 QC2.38 [1.45, 3.68]1.94-1.81 [-3.25, -0.93]3.30 [1.68, 5.03]22% [14%, 33%]57%74%+0.28+0.352026-08-08 → 2026-08-30
tmax00Znearest365d23 2 QC2.38 [1.40, 3.81]1.94-1.81 [-3.42, -0.88]3.30 [1.63, 5.10]22% [13%, 33%]57%74%+0.28+0.352026-08-08 → 2026-08-30
tmax00Znearestall23 2 QC2.38 [1.43, 3.84]1.94-1.81 [-3.38, -0.86]3.30 [1.61, 5.11]22% [14%, 36%]57%74%+0.28+0.352026-08-08 → 2026-08-30
tmax12Zbilinear30d23 2 QC2.18 [1.26, 3.39]2.12-0.69 [-2.25, 0.49]2.70 [1.56, 3.76]26% [4%, 47%]52%70%+0.34+0.292026-08-08 → 2026-08-30
tmax12Zbilinear90d23 2 QC2.18 [1.08, 3.65]2.12-0.69 [-2.41, 0.57]2.70 [1.20, 3.86]26% [0%, 50%]52%70%+0.34+0.292026-08-08 → 2026-08-30
tmax12Zbilinear365d23 2 QC2.18 [1.08, 3.68]2.12-0.69 [-2.51, 0.56]2.70 [1.20, 3.96]26% [0%, 50%]52%70%+0.34+0.292026-08-08 → 2026-08-30
tmax12Zbilinearall23 2 QC2.18 [1.07, 3.62]2.12-0.69 [-2.49, 0.59]2.70 [1.21, 3.91]26% [0%, 52%]52%70%+0.34+0.292026-08-08 → 2026-08-30
tmax12Znearest30d23 2 QC2.22 [1.33, 3.31]2.07-1.05 [-2.63, 0.28]2.80 [1.74, 3.74]30% [9%, 50%]57%65%+0.33+0.312026-08-08 → 2026-08-30
tmax12Znearest90d23 2 QC2.22 [1.13, 3.48]2.07-1.05 [-2.79, 0.41]2.80 [1.40, 3.88]30% [0%, 53%]57%65%+0.33+0.312026-08-08 → 2026-08-30
tmax12Znearest365d23 2 QC2.22 [1.14, 3.59]2.07-1.05 [-2.95, 0.44]2.80 [1.31, 3.92]30% [0%, 53%]57%65%+0.33+0.312026-08-08 → 2026-08-30
tmax12Znearestall23 2 QC2.22 [1.10, 3.51]2.07-1.05 [-2.93, 0.44]2.80 [1.42, 3.88]30% [0%, 50%]57%65%+0.33+0.312026-08-08 → 2026-08-30
tmin00Zbilinear30d23 2 QC3.42 [2.76, 4.23]1.37+3.18 [2.36, 4.15]3.72 [2.94, 4.53]0% [0%, 0%]17%48%-0.54+0.272026-08-08 → 2026-08-30
tmin00Zbilinear90d23 2 QC3.42 [2.72, 4.25]1.37+3.18 [2.30, 4.18]3.72 [2.88, 4.54]0% [0%, 0%]17%48%-0.54+0.272026-08-08 → 2026-08-30
tmin00Zbilinear365d23 2 QC3.42 [2.73, 4.33]1.37+3.18 [2.30, 4.31]3.72 [2.90, 4.64]0% [0%, 0%]17%48%-0.54+0.272026-08-08 → 2026-08-30
tmin00Zbilinearall23 2 QC3.42 [2.73, 4.50]1.37+3.18 [2.27, 4.49]3.72 [2.89, 4.78]0% [0%, 0%]17%48%-0.54+0.272026-08-08 → 2026-08-30
tmin00Znearest30d23 2 QC2.15 [1.39, 2.91]1.44+1.56 [0.56, 2.61]2.51 [1.58, 3.20]22% [4%, 42%]57%74%+0.03+0.242026-08-08 → 2026-08-30
tmin00Znearest90d23 2 QC2.15 [1.23, 2.95]1.44+1.56 [0.38, 2.69]2.51 [1.40, 3.26]22% [0%, 48%]57%74%+0.03+0.242026-08-08 → 2026-08-30
tmin00Znearest365d23 2 QC2.15 [1.26, 3.04]1.44+1.56 [0.40, 2.87]2.51 [1.40, 3.33]22% [0%, 50%]57%74%+0.03+0.242026-08-08 → 2026-08-30
tmin00Znearestall23 2 QC2.15 [1.27, 3.10]1.44+1.56 [0.39, 3.00]2.51 [1.43, 3.35]22% [0%, 46%]57%74%+0.03+0.242026-08-08 → 2026-08-30
tmin12Zbilinear30d23 2 QC3.30 [2.48, 4.33]1.35+3.30 [2.48, 4.33]3.69 [2.78, 4.58]9% [0%, 17%]26%39%-0.49+0.282026-08-08 → 2026-08-30
tmin12Zbilinear90d23 2 QC3.30 [2.48, 4.40]1.35+3.30 [2.48, 4.40]3.69 [2.78, 4.65]9% [0%, 17%]26%39%-0.49+0.282026-08-08 → 2026-08-30
tmin12Zbilinear365d23 2 QC3.30 [2.46, 4.49]1.35+3.30 [2.46, 4.49]3.69 [2.76, 4.77]9% [0%, 16%]26%39%-0.49+0.282026-08-08 → 2026-08-30
tmin12Zbilinearall23 2 QC3.30 [2.45, 4.68]1.35+3.30 [2.45, 4.68]3.69 [2.72, 4.87]9% [0%, 17%]26%39%-0.49+0.282026-08-08 → 2026-08-30
tmin12Znearest30d23 2 QC2.27 [1.49, 3.25]1.57+1.90 [0.94, 3.14]2.72 [1.71, 3.58]22% [10%, 33%]48%65%-0.02+0.172026-08-08 → 2026-08-30
tmin12Znearest90d23 2 QC2.27 [1.44, 3.32]1.57+1.90 [0.89, 3.24]2.72 [1.64, 3.66]22% [7%, 33%]48%65%-0.02+0.172026-08-08 → 2026-08-30
tmin12Znearest365d23 2 QC2.27 [1.45, 3.46]1.57+1.90 [0.86, 3.40]2.72 [1.64, 3.79]22% [5%, 33%]48%65%-0.02+0.172026-08-08 → 2026-08-30
tmin12Znearestall23 2 QC2.27 [1.41, 3.54]1.57+1.90 [0.83, 3.54]2.72 [1.59, 3.80]22% [0%, 33%]48%65%-0.02+0.172026-08-08 → 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 7, 00Z bilinear tmax+10+50-5-102026-08-08: -2.9 °F2026-08-09: +0.1 °F2026-08-10: +0.56 °F2026-08-11: +0.22 °F2026-08-12: -0.44 °F2026-08-13: +0.09 °F2026-08-14: +0.23 °F2026-08-15: +1.36 °F2026-08-16: -0.53 °F2026-08-17: -1.45 °F2026-08-18: -1.71 °F2026-08-19: -2.13 °F2026-08-20: +0.97 °F2026-08-21: -3.16 °F2026-08-22: +4.17 °F2026-08-23: -2.19 °F2026-08-24: +0.47 °F2026-08-25: -1.72 °F2026-08-26: -4.95 °F2026-08-27: -9.67 °F2026-08-28: -3.75 °F2026-08-29: -1.61 °F2026-08-30: +1.19 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.19
2026-08-29-1.61
2026-08-28-3.75
2026-08-27-9.67
2026-08-26-4.95
2026-08-25-1.72
2026-08-24+0.47
2026-08-23-2.19
2026-08-22+4.17
2026-08-21-3.16
2026-08-20+0.97
2026-08-19-2.13
2026-08-18-1.71
2026-08-17-1.45
2026-08-16-0.53
2026-08-15+1.36
2026-08-14+0.23
2026-08-13+0.09
2026-08-12-0.44
2026-08-11+0.22
2026-08-10+0.56
2026-08-09+0.10
2026-08-08-2.90

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAX, lead day 7-10 to -9 °F: 1 day-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 1 day-4 to -3 °F: 2 days-3 to -2 °F: 3 days-2 to -1 °F: 4 days-1 to 0 °F: 2 days0 to 1 °F: 7 days1 to 2 °F: 2 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 1 day5 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| 1.45 · P90 |e| 4.09 °F-100+10 °Fn = 23 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
-10.00-9.001
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.000
-5.00-4.001
-4.00-3.002
-3.00-2.003
-2.00-1.004
-1.00+0.002
+0.00+1.007
+1.00+2.002
+2.00+3.000
+3.00+4.000
+4.00+5.001
+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
2026-08231.98 -1.17

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23

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 23 -0.04 [-1.03, 1.32] no
GraphCast (IFS init) 23 -2.51 [-3.51, -1.57] yes
ECMWF IFS HRES 18 -0.61 [-2.25, 2.19] no
Persistence (baseline) 23 -1.32 [-2.13, -0.42] yes

Cite this page

ShortCastCheck, KLAX gfs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAX/model/gfs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), model gfs, lead day 7. 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/7/

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