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

Chicago O'Hare · Pangu-Weather (GFS init) · lead day 1

KORD · pangu_gfs · lead 1

Target day = initialization date + 1 day. 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, PANG_v100, starting 2026-08-28 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 1 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
tmax00Zbilinear30d1 1 QC4.23 [4.23, 4.23]0.00-4.23 [-4.23, -4.23]4.23 [4.23, 4.23]0% [0%, 0%]0%0%-3.23—2026-08-30 → 2026-08-30
tmax00Zbilinear90d1 1 QC4.23 [4.23, 4.23]0.00-4.23 [-4.23, -4.23]4.23 [4.23, 4.23]0% [0%, 0%]0%0%-3.23—2026-08-30 → 2026-08-30
tmax00Zbilinear365d1 1 QC4.23 [4.23, 4.23]0.00-4.23 [-4.23, -4.23]4.23 [4.23, 4.23]0% [0%, 0%]0%0%-3.23—2026-08-30 → 2026-08-30
tmax00Zbilinearall1 1 QC4.23 [4.23, 4.23]0.00-4.23 [-4.23, -4.23]4.23 [4.23, 4.23]0% [0%, 0%]0%0%-3.23—2026-08-30 → 2026-08-30
tmax00Znearest30d1 1 QC4.07 [4.07, 4.07]0.00-4.07 [-4.07, -4.07]4.07 [4.07, 4.07]0% [0%, 0%]0%0%-3.07—2026-08-30 → 2026-08-30
tmax00Znearest90d1 1 QC4.07 [4.07, 4.07]0.00-4.07 [-4.07, -4.07]4.07 [4.07, 4.07]0% [0%, 0%]0%0%-3.07—2026-08-30 → 2026-08-30
tmax00Znearest365d1 1 QC4.07 [4.07, 4.07]0.00-4.07 [-4.07, -4.07]4.07 [4.07, 4.07]0% [0%, 0%]0%0%-3.07—2026-08-30 → 2026-08-30
tmax00Znearestall1 1 QC4.07 [4.07, 4.07]0.00-4.07 [-4.07, -4.07]4.07 [4.07, 4.07]0% [0%, 0%]0%0%-3.07—2026-08-30 → 2026-08-30
tmax12Zbilinear30d2 1 QC1.45 [0.56, 2.35]1.45-0.89 [-2.35, 0.56]1.71 [0.56, 2.35]50% [0%, 100%]50%100%+0.03+0.032026-08-29 → 2026-08-30
tmax12Zbilinear90d2 1 QC1.45 [0.56, 2.35]1.45-0.89 [-2.35, 0.56]1.71 [0.56, 2.35]50% [0%, 100%]50%100%+0.03+0.032026-08-29 → 2026-08-30
tmax12Zbilinear365d2 1 QC1.45 [0.56, 2.35]1.45-0.89 [-2.35, 0.56]1.71 [0.56, 2.35]50% [0%, 100%]50%100%+0.03+0.032026-08-29 → 2026-08-30
tmax12Zbilinearall2 1 QC1.45 [0.56, 2.35]1.45-0.89 [-2.35, 0.56]1.71 [0.56, 2.35]50% [0%, 100%]50%100%+0.03+0.032026-08-29 → 2026-08-30
tmax12Znearest30d2 1 QC1.61 [0.97, 2.26]1.61-0.64 [-2.26, 0.97]1.74 [0.97, 2.26]50% [0%, 100%]50%100%-0.08-0.082026-08-29 → 2026-08-30
tmax12Znearest90d2 1 QC1.61 [0.97, 2.26]1.61-0.64 [-2.26, 0.97]1.74 [0.97, 2.26]50% [0%, 100%]50%100%-0.08-0.082026-08-29 → 2026-08-30
tmax12Znearest365d2 1 QC1.61 [0.97, 2.26]1.61-0.64 [-2.26, 0.97]1.74 [0.97, 2.26]50% [0%, 100%]50%100%-0.08-0.082026-08-29 → 2026-08-30
tmax12Znearestall2 1 QC1.61 [0.97, 2.26]1.61-0.64 [-2.26, 0.97]1.74 [0.97, 2.26]50% [0%, 100%]50%100%-0.08-0.082026-08-29 → 2026-08-30
tmin00Zbilinear30d1 1 QC2.01 [2.01, 2.01]0.00+2.01 [2.01, 2.01]2.01 [2.01, 2.01]0% [0%, 0%]0%100%+0.50—2026-08-30 → 2026-08-30
tmin00Zbilinear90d1 1 QC2.01 [2.01, 2.01]0.00+2.01 [2.01, 2.01]2.01 [2.01, 2.01]0% [0%, 0%]0%100%+0.50—2026-08-30 → 2026-08-30
tmin00Zbilinear365d1 1 QC2.01 [2.01, 2.01]0.00+2.01 [2.01, 2.01]2.01 [2.01, 2.01]0% [0%, 0%]0%100%+0.50—2026-08-30 → 2026-08-30
tmin00Zbilinearall1 1 QC2.01 [2.01, 2.01]0.00+2.01 [2.01, 2.01]2.01 [2.01, 2.01]0% [0%, 0%]0%100%+0.50—2026-08-30 → 2026-08-30
tmin00Znearest30d1 1 QC1.70 [1.70, 1.70]0.00+1.70 [1.70, 1.70]1.70 [1.70, 1.70]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmin00Znearest90d1 1 QC1.70 [1.70, 1.70]0.00+1.70 [1.70, 1.70]1.70 [1.70, 1.70]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmin00Znearest365d1 1 QC1.70 [1.70, 1.70]0.00+1.70 [1.70, 1.70]1.70 [1.70, 1.70]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmin00Znearestall1 1 QC1.70 [1.70, 1.70]0.00+1.70 [1.70, 1.70]1.70 [1.70, 1.70]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmin12Zbilinear30d2 1 QC3.49 [2.88, 4.10]0.61+3.49 [2.88, 4.10]3.54 [2.88, 4.10]0% [0%, 0%]0%50%-0.40+0.762026-08-29 → 2026-08-30
tmin12Zbilinear90d2 1 QC3.49 [2.88, 4.10]0.61+3.49 [2.88, 4.10]3.54 [2.88, 4.10]0% [0%, 0%]0%50%-0.40+0.762026-08-29 → 2026-08-30
tmin12Zbilinear365d2 1 QC3.49 [2.88, 4.10]0.61+3.49 [2.88, 4.10]3.54 [2.88, 4.10]0% [0%, 0%]0%50%-0.40+0.762026-08-29 → 2026-08-30
tmin12Zbilinearall2 1 QC3.49 [2.88, 4.10]0.61+3.49 [2.88, 4.10]3.54 [2.88, 4.10]0% [0%, 0%]0%50%-0.40+0.762026-08-29 → 2026-08-30
tmin12Znearest30d2 1 QC3.04 [2.56, 3.52]0.48+3.04 [2.56, 3.52]3.08 [2.56, 3.52]0% [0%, 0%]0%50%-0.22+0.812026-08-29 → 2026-08-30
tmin12Znearest90d2 1 QC3.04 [2.56, 3.52]0.48+3.04 [2.56, 3.52]3.08 [2.56, 3.52]0% [0%, 0%]0%50%-0.22+0.812026-08-29 → 2026-08-30
tmin12Znearest365d2 1 QC3.04 [2.56, 3.52]0.48+3.04 [2.56, 3.52]3.08 [2.56, 3.52]0% [0%, 0%]0%50%-0.22+0.812026-08-29 → 2026-08-30
tmin12Znearestall2 1 QC3.04 [2.56, 3.52]0.48+3.04 [2.56, 3.52]3.08 [2.56, 3.52]0% [0%, 0%]0%50%-0.22+0.812026-08-29 → 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 Pangu-Weather (GFS init) at KORD, lead day 1, 00Z bilinear tmax+5+2.50-2.5-52026-08-30: -4.23 °F2026-08-30°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 (1 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.23

Error distribution

Distribution of the signed daily error in °F for Pangu-Weather (GFS init) at KORD, lead day 1-5 to -4.5 °F: 0 days-4.5 to -4 °F: 1 day-4 to -3.5 °F: 0 days-3.5 to -3 °F: 0 days-3 to -2.5 °F: 0 days-2.5 to -2 °F: 0 days-2 to -1.5 °F: 0 days-1.5 to -1 °F: 0 days-1 to -0.5 °F: 0 days-0.5 to 0 °F: 0 days0 to 0.5 °F: 0 days0.5 to 1 °F: 0 days1 to 1.5 °F: 0 days1.5 to 2 °F: 0 days2 to 2.5 °F: 0 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 4.23 · P90 |e| 4.23 °F-50+5 °Fn = 1 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
-5.00-4.500
-4.50-4.001
-4.00-3.500
-3.50-3.000
-3.00-2.500
-2.50-2.000
-2.00-1.500
-1.50-1.000
-1.00-0.500
-0.50+0.000
+0.00+0.500
+0.50+1.000
+1.00+1.500
+1.50+2.000
+2.00+2.500
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-0814.23 -4.23

Availability

ModelScored period DaysCoverage
Pangu-Weather (GFS init)2026-08-30 → 2026-08-30 1
Pangu-Weather (GFS init)2026-08-30 → 2026-08-30 1
Pangu-Weather (GFS init)2026-08-29 → 2026-08-30 2
Pangu-Weather (GFS init)2026-08-29 → 2026-08-30 2

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 1 +1.56 [1.56, 1.56] yes
Aurora (GFS init) 1 -2.47 [-2.47, -2.47] yes
Aurora (IFS init) 1 +1.53 [1.53, 1.53] yes
FourCastNet v2 (GFS init) 1 +1.60 [1.60, 1.60] yes
FourCastNet v2 (IFS init) 1 +2.03 [2.03, 2.03] yes
NCEP GFS 1 +1.77 [1.77, 1.77] yes
GraphCast (GFS init) 1 -2.71 [-2.71, -2.71] yes
GraphCast (IFS init) 1 -0.48 [-0.48, -0.48] yes
ECMWF IFS HRES 1 +1.98 [1.98, 1.98] yes
Pangu-Weather (IFS init) 1 +0.40 [0.40, 0.40] yes
Persistence (baseline) 1 +3.23 [3.23, 3.23] yes

Cite this page

ShortCastCheck, KORD pangu_gfs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KORD/model/pangu_gfs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KORD (Chicago O'Hare), model pangu_gfs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KORD/model/pangu_gfs/lead/1/

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