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 · GraphCast (IFS init) · lead day 6

KLAX · graphcast_ifs · lead 6

Target day = initialization date + 6 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, GRAP_v100, starting 2026-01-01 — 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
tmax00Zbilinear30d24 2 QC4.15 [2.81, 5.52]1.88-4.15 [-5.52, -2.81]4.71 [3.11, 5.90]4% [0%, 12%]21%42%-0.35+0.342026-08-07 → 2026-08-30
tmax00Zbilinear90d24 2 QC4.15 [2.71, 5.60]1.88-4.15 [-5.60, -2.71]4.71 [2.92, 5.92]4% [0%, 12%]21%42%-0.35+0.342026-08-07 → 2026-08-30
tmax00Zbilinear365d30 2 QC3.86 [2.61, 5.23]2.04-3.64 [-5.21, -2.20]4.44 [2.96, 5.65]7% [0%, 17%]23%43%-0.15+0.372026-01-07 → 2026-08-30
tmax00Zbilinearall30 2 QC3.86 [2.63, 5.25]2.04-3.64 [-5.22, -2.14]4.44 [2.97, 5.69]7% [0%, 16%]23%43%-0.15+0.372026-01-07 → 2026-08-30
tmax00Znearest30d24 2 QC7.14 [5.60, 8.78]1.93-7.14 [-8.78, -5.60]7.52 [5.76, 9.01]0% [0%, 0%]0%4%-1.32+0.322026-08-07 → 2026-08-30
tmax00Znearest90d24 2 QC7.14 [5.48, 8.96]1.93-7.14 [-8.96, -5.48]7.52 [5.58, 9.15]0% [0%, 0%]0%4%-1.32+0.322026-08-07 → 2026-08-30
tmax00Znearest365d30 2 QC6.29 [4.21, 8.32]2.48-6.10 [-8.22, -3.72]6.88 [4.66, 8.61]3% [0%, 12%]7%17%-0.87+0.232026-01-07 → 2026-08-30
tmax00Znearestall30 2 QC6.29 [4.07, 8.31]2.48-6.10 [-8.28, -3.52]6.88 [4.56, 8.63]3% [0%, 13%]7%17%-0.87+0.232026-01-07 → 2026-08-30
tmax12Zbilinear30d24 2 QC3.75 [2.53, 5.03]1.75-3.73 [-5.01, -2.53]4.25 [2.83, 5.36]4% [0%, 12%]25%42%-0.22+0.382026-08-07 → 2026-08-30
tmax12Zbilinear90d24 2 QC3.75 [2.44, 5.23]1.75-3.73 [-5.23, -2.44]4.25 [2.58, 5.50]4% [0%, 12%]25%42%-0.22+0.382026-08-07 → 2026-08-30
tmax12Zbilinear365d29 2 QC3.63 [2.51, 4.93]1.88-3.37 [-4.81, -2.08]4.14 [2.77, 5.27]7% [0%, 17%]24%41%-0.12+0.402026-01-07 → 2026-08-30
tmax12Zbilinearall29 2 QC3.63 [2.53, 4.89]1.88-3.37 [-4.78, -2.09]4.14 [2.85, 5.24]7% [0%, 17%]24%41%-0.12+0.402026-01-07 → 2026-08-30
tmax12Znearest30d24 2 QC6.88 [5.44, 8.41]1.81-6.88 [-8.41, -5.44]7.21 [5.63, 8.57]0% [0%, 0%]0%4%-1.23+0.362026-08-07 → 2026-08-30
tmax12Znearest90d24 2 QC6.88 [5.32, 8.67]1.81-6.88 [-8.67, -5.32]7.21 [5.45, 8.76]0% [0%, 0%]0%4%-1.23+0.362026-08-07 → 2026-08-30
tmax12Znearest365d29 2 QC6.22 [4.35, 8.06]2.28-6.02 [-8.06, -3.79]6.72 [4.77, 8.32]3% [0%, 13%]3%14%-0.92+0.272026-01-07 → 2026-08-30
tmax12Znearestall29 2 QC6.22 [4.27, 8.02]2.28-6.02 [-8.00, -3.60]6.72 [4.69, 8.26]3% [0%, 14%]3%14%-0.92+0.272026-01-07 → 2026-08-30
tmin00Zbilinear30d24 2 QC1.04 [0.73, 1.32]0.84-0.61 [-1.13, -0.11]1.21 [0.89, 1.44]50% [19%, 82%]92%100%+0.50+0.542026-08-07 → 2026-08-30
tmin00Zbilinear90d24 2 QC1.04 [0.59, 1.32]0.84-0.61 [-1.19, -0.07]1.21 [0.75, 1.44]50% [19%, 89%]92%100%+0.50+0.542026-08-07 → 2026-08-30
tmin00Zbilinear365d30 2 QC2.42 [0.85, 5.28]2.80+1.10 [-0.90, 4.68]3.91 [1.03, 6.74]40% [8%, 75%]73%80%+0.30+0.232026-01-07 → 2026-08-30
tmin00Zbilinearall30 2 QC2.42 [0.89, 5.79]2.80+1.10 [-0.90, 5.20]3.91 [1.07, 7.04]40% [7%, 73%]73%80%+0.30+0.232026-01-07 → 2026-08-30
tmin00Znearest30d24 2 QC0.80 [0.60, 1.01]0.78+0.37 [-0.11, 0.75]1.09 [0.74, 1.34]71% [56%, 86%]92%96%+0.62+0.572026-08-07 → 2026-08-30
tmin00Znearest90d24 2 QC0.80 [0.55, 1.01]0.78+0.37 [-0.20, 0.76]1.09 [0.68, 1.33]71% [56%, 91%]92%96%+0.62+0.572026-08-07 → 2026-08-30
tmin00Znearest365d30 2 QC2.75 [0.68, 6.91]3.31+2.41 [0.11, 6.74]5.09 [0.90, 9.01]57% [24%, 80%]73%77%+0.20+0.092026-01-07 → 2026-08-30
tmin00Znearestall30 2 QC2.75 [0.68, 7.58]3.31+2.41 [0.12, 7.34]5.09 [0.92, 9.40]57% [24%, 80%]73%77%+0.20+0.092026-01-07 → 2026-08-30
tmin12Zbilinear30d24 2 QC0.97 [0.75, 1.17]0.76-0.54 [-0.99, -0.15]1.12 [0.87, 1.34]62% [46%, 82%]92%100%+0.53+0.592026-08-07 → 2026-08-30
tmin12Zbilinear90d24 2 QC0.97 [0.69, 1.19]0.76-0.54 [-1.08, -0.10]1.12 [0.78, 1.37]62% [46%, 89%]92%100%+0.53+0.592026-08-07 → 2026-08-30
tmin12Zbilinear365d29 2 QC2.16 [0.84, 4.90]2.45+0.90 [-0.82, 4.28]3.64 [0.95, 6.45]52% [24%, 75%]76%83%+0.36+0.312026-01-07 → 2026-08-30
tmin12Zbilinearall29 2 QC2.16 [0.85, 5.52]2.45+0.90 [-0.81, 4.89]3.64 [0.96, 6.87]52% [21%, 75%]76%83%+0.36+0.312026-01-07 → 2026-08-30
tmin12Znearest30d24 2 QC0.81 [0.55, 1.02]0.77+0.48 [-0.04, 0.82]1.09 [0.73, 1.30]67% [52%, 81%]92%100%+0.61+0.582026-08-07 → 2026-08-30
tmin12Znearest90d24 2 QC0.81 [0.49, 1.03]0.77+0.48 [-0.15, 0.85]1.09 [0.65, 1.31]67% [50%, 85%]92%100%+0.61+0.582026-08-07 → 2026-08-30
tmin12Znearest365d29 2 QC2.45 [0.65, 6.30]2.86+2.18 [0.22, 6.21]4.69 [0.89, 8.59]55% [28%, 76%]76%83%+0.27+0.202026-01-07 → 2026-08-30
tmin12Znearestall29 2 QC2.45 [0.67, 6.94]2.86+2.18 [0.20, 6.77]4.69 [0.90, 8.97]55% [25%, 75%]76%83%+0.27+0.202026-01-07 → 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 GraphCast (IFS init) at KLAX, lead day 6, 00Z bilinear tmax+10+50-5-102026-08-07: -4.15 °F2026-08-08: -2.75 °F2026-08-09: -2.94 °F2026-08-10: -1.55 °F2026-08-11: -2.87 °F2026-08-12: -1.45 °F2026-08-13: -1.38 °F2026-08-14: -3.56 °F2026-08-15: -2.27 °F2026-08-16: -1.81 °F2026-08-17: -5.12 °F2026-08-18: -7.21 °F2026-08-19: -4.41 °F2026-08-20: -0.1 °F2026-08-21: -5.98 °F2026-08-22: -4.34 °F2026-08-23: -8.62 °F2026-08-24: -6.66 °F2026-08-25: -3.54 °F2026-08-26: -5.75 °F2026-08-27: -8.18 °F2026-08-28: -2.98 °F2026-08-29: -6.05 °F2026-08-30: -5.93 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.93
2026-08-29-6.05
2026-08-28-2.98
2026-08-27-8.18
2026-08-26-5.75
2026-08-25-3.54
2026-08-24-6.66
2026-08-23-8.62
2026-08-22-4.34
2026-08-21-5.98
2026-08-20-0.10
2026-08-19-4.41
2026-08-18-7.21
2026-08-17-5.12
2026-08-16-1.81
2026-08-15-2.27
2026-08-14-3.56
2026-08-13-1.38
2026-08-12-1.45
2026-08-11-2.87
2026-08-10-1.55
2026-08-09-2.94
2026-08-08-2.75
2026-08-07-4.15

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KLAX, lead day 6-10 to -9 °F: 0 days-9 to -8 °F: 2 days-8 to -7 °F: 1 day-7 to -6 °F: 2 days-6 to -5 °F: 5 days-5 to -4 °F: 3 days-4 to -3 °F: 3 days-3 to -2 °F: 6 days-2 to -1 °F: 5 days-1 to 0 °F: 2 days0 to 1 °F: 0 days1 to 2 °F: 0 days2 to 3 °F: 0 days3 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| 3.43 · P90 |e| 6.72 °F-100+10 °Fn = 30 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
-9.00-8.002
-8.00-7.001
-7.00-6.002
-6.00-5.005
-5.00-4.003
-4.00-3.003
-3.00-2.006
-2.00-1.005
-1.00+0.002
+0.00+1.000
+1.00+2.000
+2.00+3.000
+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
2026-08244.15 -4.15
2026-0162.68 -1.60

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-07 → 2026-08-30 30
GraphCast (IFS init)2026-01-07 → 2026-08-30 30
GraphCast (IFS init)2026-01-07 → 2026-08-30 29
GraphCast (IFS init)2026-01-07 → 2026-08-30 29

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 24 +2.00 [1.10, 3.05] yes
NCEP GFS 24 +2.29 [1.45, 3.14] yes
ECMWF IFS HRES 19 +2.20 [1.35, 3.22] yes
Persistence (baseline) 24 +1.07 [0.53, 2.36] yes

Cite this page

ShortCastCheck, KLAX graphcast_ifs lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAX/model/graphcast_ifs/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAX (Los Angeles Intl), model graphcast_ifs, lead day 6. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KLAX/model/graphcast_ifs/lead/6/

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