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 2

KLAX · gfs · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 2 QC2.25 [1.66, 2.93]2.25-0.52 [-2.04, 0.90]2.90 [2.02, 3.81]25% [12%, 38%]57%71%-0.19-0.142026-08-03 → 2026-08-30
tmax00Zbilinear90d28 2 QC2.25 [1.62, 3.02]2.25-0.52 [-2.30, 1.28]2.90 [1.99, 3.88]25% [11%, 39%]57%71%-0.19-0.142026-08-03 → 2026-08-30
tmax00Zbilinear365d28 2 QC2.25 [1.63, 3.14]2.25-0.52 [-2.63, 1.35]2.90 [1.97, 4.12]25% [9%, 38%]57%71%-0.19-0.142026-08-03 → 2026-08-30
tmax00Zbilinearall28 2 QC2.25 [1.61, 3.09]2.25-0.52 [-2.32, 1.11]2.90 [1.94, 3.90]25% [8%, 38%]57%71%-0.19-0.142026-08-03 → 2026-08-30
tmax00Znearest30d28 2 QC2.25 [1.24, 3.29]2.20-1.38 [-2.68, -0.12]3.10 [1.74, 4.24]32% [11%, 57%]57%75%-0.19-0.112026-08-03 → 2026-08-30
tmax00Znearest90d28 2 QC2.25 [1.00, 3.41]2.20-1.38 [-2.99, 0.21]3.10 [1.38, 4.32]32% [7%, 60%]57%75%-0.19-0.112026-08-03 → 2026-08-30
tmax00Znearest365d28 2 QC2.25 [1.07, 3.70]2.20-1.38 [-3.25, 0.25]3.10 [1.42, 4.58]32% [0%, 60%]57%75%-0.19-0.112026-08-03 → 2026-08-30
tmax00Znearestall28 2 QC2.25 [1.07, 3.56]2.20-1.38 [-3.04, 0.12]3.10 [1.46, 4.42]32% [5%, 62%]57%75%-0.19-0.112026-08-03 → 2026-08-30
tmax12Zbilinear30d28 2 QC2.15 [1.62, 2.66]2.06-0.63 [-1.86, 0.59]2.53 [1.94, 3.00]21% [4%, 38%]50%82%-0.14-0.042026-08-03 → 2026-08-30
tmax12Zbilinear90d28 2 QC2.15 [1.55, 2.70]2.06-0.63 [-2.09, 0.91]2.53 [1.85, 3.05]21% [0%, 38%]50%82%-0.14-0.042026-08-03 → 2026-08-30
tmax12Zbilinear365d28 2 QC2.15 [1.60, 2.79]2.06-0.63 [-2.29, 0.99]2.53 [1.85, 3.14]21% [0%, 39%]50%82%-0.14-0.042026-08-03 → 2026-08-30
tmax12Zbilinearall28 2 QC2.15 [1.60, 2.78]2.06-0.63 [-2.13, 0.77]2.53 [1.86, 3.13]21% [0%, 41%]50%82%-0.14-0.042026-08-03 → 2026-08-30
tmax12Znearest30d28 2 QC2.42 [1.53, 3.22]2.12-1.49 [-2.55, -0.40]2.89 [1.98, 3.58]25% [7%, 50%]50%61%-0.28-0.072026-08-03 → 2026-08-30
tmax12Znearest90d28 2 QC2.42 [1.31, 3.27]2.12-1.49 [-2.79, -0.14]2.89 [1.67, 3.63]25% [0%, 60%]50%61%-0.28-0.072026-08-03 → 2026-08-30
tmax12Znearest365d28 2 QC2.42 [1.30, 3.42]2.12-1.49 [-2.96, -0.04]2.89 [1.68, 3.74]25% [0%, 57%]50%61%-0.28-0.072026-08-03 → 2026-08-30
tmax12Znearestall28 2 QC2.42 [1.34, 3.36]2.12-1.49 [-2.84, -0.15]2.89 [1.80, 3.71]25% [0%, 59%]50%61%-0.28-0.072026-08-03 → 2026-08-30
tmin00Zbilinear30d28 2 QC3.67 [2.73, 4.47]1.47+3.58 [2.49, 4.47]4.03 [3.18, 4.68]14% [0%, 32%]14%32%-1.93-0.152026-08-03 → 2026-08-30
tmin00Zbilinear90d28 2 QC3.67 [2.67, 4.59]1.47+3.58 [2.42, 4.59]4.03 [3.09, 4.77]14% [0%, 31%]14%32%-1.93-0.152026-08-03 → 2026-08-30
tmin00Zbilinear365d28 2 QC3.67 [2.55, 4.66]1.47+3.58 [2.32, 4.66]4.03 [2.92, 4.81]14% [0%, 33%]14%32%-1.93-0.152026-08-03 → 2026-08-30
tmin00Zbilinearall28 2 QC3.67 [2.60, 4.71]1.47+3.58 [2.36, 4.71]4.03 [2.99, 4.85]14% [0%, 32%]14%32%-1.93-0.152026-08-03 → 2026-08-30
tmin00Znearest30d28 2 QC2.51 [1.87, 3.16]1.58+2.13 [1.08, 3.12]2.88 [2.20, 3.47]18% [7%, 32%]39%61%-1.01-0.242026-08-03 → 2026-08-30
tmin00Znearest90d28 2 QC2.51 [1.74, 3.24]1.58+2.13 [0.97, 3.21]2.88 [2.05, 3.53]18% [4%, 35%]39%61%-1.01-0.242026-08-03 → 2026-08-30
tmin00Znearest365d28 2 QC2.51 [1.58, 3.34]1.58+2.13 [0.80, 3.31]2.88 [1.89, 3.56]18% [0%, 36%]39%61%-1.01-0.242026-08-03 → 2026-08-30
tmin00Znearestall28 2 QC2.51 [1.69, 3.30]1.58+2.13 [0.87, 3.29]2.88 [2.06, 3.56]18% [0%, 35%]39%61%-1.01-0.242026-08-03 → 2026-08-30
tmin12Zbilinear30d28 2 QC3.47 [2.60, 4.29]1.40+3.30 [2.22, 4.29]3.79 [2.95, 4.53]7% [0%, 20%]18%39%-1.77-0.102026-08-03 → 2026-08-30
tmin12Zbilinear90d28 2 QC3.47 [2.58, 4.37]1.40+3.30 [2.20, 4.35]3.79 [2.86, 4.61]7% [0%, 19%]18%39%-1.77-0.102026-08-03 → 2026-08-30
tmin12Zbilinear365d28 2 QC3.47 [2.46, 4.40]1.40+3.30 [1.99, 4.40]3.79 [2.73, 4.62]7% [0%, 20%]18%39%-1.77-0.102026-08-03 → 2026-08-30
tmin12Zbilinearall28 2 QC3.47 [2.49, 4.46]1.40+3.30 [2.08, 4.46]3.79 [2.79, 4.66]7% [0%, 20%]18%39%-1.77-0.102026-08-03 → 2026-08-30
tmin12Znearest30d28 2 QC2.36 [1.76, 3.01]1.51+1.89 [0.79, 2.89]2.72 [2.04, 3.35]14% [3%, 25%]43%71%-0.89-0.182026-08-03 → 2026-08-30
tmin12Znearest90d28 2 QC2.36 [1.65, 3.08]1.51+1.89 [0.77, 2.96]2.72 [1.90, 3.38]14% [0%, 29%]43%71%-0.89-0.182026-08-03 → 2026-08-30
tmin12Znearest365d28 2 QC2.36 [1.55, 3.11]1.51+1.89 [0.60, 3.04]2.72 [1.84, 3.41]14% [0%, 33%]43%71%-0.89-0.182026-08-03 → 2026-08-30
tmin12Znearestall28 2 QC2.36 [1.65, 3.11]1.51+1.89 [0.64, 3.06]2.72 [1.88, 3.43]14% [0%, 32%]43%71%-0.89-0.182026-08-03 → 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 2, 00Z bilinear tmax+10+50-5-102026-08-03: +3.47 °F2026-08-04: +1.85 °F2026-08-05: +3.08 °F2026-08-06: +1.08 °F2026-08-07: -0.02 °F2026-08-08: +2.19 °F2026-08-09: +0.67 °F2026-08-10: +1.08 °F2026-08-11: -1.4 °F2026-08-12: -1.82 °F2026-08-13: -4.34 °F2026-08-14: -4.69 °F2026-08-15: -2.32 °F2026-08-16: +1.13 °F2026-08-17: +2.51 °F2026-08-18: +0.64 °F2026-08-19: +0.98 °F2026-08-20: +3.99 °F2026-08-21: -1.61 °F2026-08-22: -0.43 °F2026-08-23: -2.1 °F2026-08-24: -0.78 °F2026-08-25: +1.46 °F2026-08-26: -1.51 °F2026-08-27: -8.88 °F2026-08-28: -0.69 °F2026-08-29: -4.72 °F2026-08-30: -3.45 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.45
2026-08-29-4.72
2026-08-28-0.69
2026-08-27-8.88
2026-08-26-1.51
2026-08-25+1.46
2026-08-24-0.78
2026-08-23-2.10
2026-08-22-0.43
2026-08-21-1.61
2026-08-20+3.99
2026-08-19+0.98
2026-08-18+0.64
2026-08-17+2.51
2026-08-16+1.13
2026-08-15-2.32
2026-08-14-4.69
2026-08-13-4.34
2026-08-12-1.82
2026-08-11-1.40
2026-08-10+1.08
2026-08-09+0.67
2026-08-08+2.19
2026-08-07-0.02
2026-08-06+1.08
2026-08-05+3.08
2026-08-04+1.85
2026-08-03+3.47

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAX, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 3 days-4 to -3 °F: 1 day-3 to -2 °F: 2 days-2 to -1 °F: 4 days-1 to 0 °F: 4 days0 to 1 °F: 3 days1 to 2 °F: 5 days2 to 3 °F: 2 days3 to 4 °F: 3 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| 1.72 · P90 |e| 4.45 °F-100+10 °Fn = 28 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
-9.00-8.001
-8.00-7.000
-7.00-6.000
-6.00-5.000
-5.00-4.003
-4.00-3.001
-3.00-2.002
-2.00-1.004
-1.00+0.004
+0.00+1.003
+1.00+2.005
+2.00+3.002
+3.00+4.003
+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
2026-08282.25 -0.52

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28

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 28 +0.53 [-0.24, 1.39] no
Aurora (IFS init) 1 -2.84 [-2.84, -2.84] yes
FourCastNet v2 (IFS init) 1 +0.32 [0.32, 0.32] yes
GraphCast (IFS init) 26 -1.50 [-2.14, -0.78] yes
ECMWF IFS HRES 23 +0.08 [-0.72, 1.34] no
Pangu-Weather (IFS init) 1 -0.59 [-0.59, -0.59] yes
Persistence (baseline) 28 +0.35 [-0.71, 1.27] no

Cite this page

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

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

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