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

Chicago O'Hare · Aurora (IFS init) · lead day 2

KORD · aurora_ifs · 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, AURO_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 QC1.43 [1.43, 1.43]0.00-1.43 [-1.43, -1.43]1.43 [1.43, 1.43]0% [0%, 0%]100%100%-0.43—2026-08-30 → 2026-08-30
tmax00Zbilinear90d1 1 QC1.43 [1.43, 1.43]0.00-1.43 [-1.43, -1.43]1.43 [1.43, 1.43]0% [0%, 0%]100%100%-0.43—2026-08-30 → 2026-08-30
tmax00Zbilinear365d1 1 QC1.43 [1.43, 1.43]0.00-1.43 [-1.43, -1.43]1.43 [1.43, 1.43]0% [0%, 0%]100%100%-0.43—2026-08-30 → 2026-08-30
tmax00Zbilinearall1 1 QC1.43 [1.43, 1.43]0.00-1.43 [-1.43, -1.43]1.43 [1.43, 1.43]0% [0%, 0%]100%100%-0.43—2026-08-30 → 2026-08-30
tmax00Znearest30d1 1 QC1.17 [1.17, 1.17]0.00-1.17 [-1.17, -1.17]1.17 [1.17, 1.17]0% [0%, 0%]100%100%-0.17—2026-08-30 → 2026-08-30
tmax00Znearest90d1 1 QC1.17 [1.17, 1.17]0.00-1.17 [-1.17, -1.17]1.17 [1.17, 1.17]0% [0%, 0%]100%100%-0.17—2026-08-30 → 2026-08-30
tmax00Znearest365d1 1 QC1.17 [1.17, 1.17]0.00-1.17 [-1.17, -1.17]1.17 [1.17, 1.17]0% [0%, 0%]100%100%-0.17—2026-08-30 → 2026-08-30
tmax00Znearestall1 1 QC1.17 [1.17, 1.17]0.00-1.17 [-1.17, -1.17]1.17 [1.17, 1.17]0% [0%, 0%]100%100%-0.17—2026-08-30 → 2026-08-30
tmax12Zbilinear30d1 1 QC1.83 [1.83, 1.83]0.00-1.83 [-1.83, -1.83]1.83 [1.83, 1.83]0% [0%, 0%]100%100%-0.83—2026-08-30 → 2026-08-30
tmax12Zbilinear90d1 1 QC1.83 [1.83, 1.83]0.00-1.83 [-1.83, -1.83]1.83 [1.83, 1.83]0% [0%, 0%]100%100%-0.83—2026-08-30 → 2026-08-30
tmax12Zbilinear365d1 1 QC1.83 [1.83, 1.83]0.00-1.83 [-1.83, -1.83]1.83 [1.83, 1.83]0% [0%, 0%]100%100%-0.83—2026-08-30 → 2026-08-30
tmax12Zbilinearall1 1 QC1.83 [1.83, 1.83]0.00-1.83 [-1.83, -1.83]1.83 [1.83, 1.83]0% [0%, 0%]100%100%-0.83—2026-08-30 → 2026-08-30
tmax12Znearest30d1 1 QC1.44 [1.44, 1.44]0.00-1.44 [-1.44, -1.44]1.44 [1.44, 1.44]0% [0%, 0%]100%100%-0.44—2026-08-30 → 2026-08-30
tmax12Znearest90d1 1 QC1.44 [1.44, 1.44]0.00-1.44 [-1.44, -1.44]1.44 [1.44, 1.44]0% [0%, 0%]100%100%-0.44—2026-08-30 → 2026-08-30
tmax12Znearest365d1 1 QC1.44 [1.44, 1.44]0.00-1.44 [-1.44, -1.44]1.44 [1.44, 1.44]0% [0%, 0%]100%100%-0.44—2026-08-30 → 2026-08-30
tmax12Znearestall1 1 QC1.44 [1.44, 1.44]0.00-1.44 [-1.44, -1.44]1.44 [1.44, 1.44]0% [0%, 0%]100%100%-0.44—2026-08-30 → 2026-08-30
tmin00Zbilinear30d1 1 QC0.40 [0.40, 0.40]0.00+0.40 [0.40, 0.40]0.40 [0.40, 0.40]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin00Zbilinear90d1 1 QC0.40 [0.40, 0.40]0.00+0.40 [0.40, 0.40]0.40 [0.40, 0.40]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin00Zbilinear365d1 1 QC0.40 [0.40, 0.40]0.00+0.40 [0.40, 0.40]0.40 [0.40, 0.40]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin00Zbilinearall1 1 QC0.40 [0.40, 0.40]0.00+0.40 [0.40, 0.40]0.40 [0.40, 0.40]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin00Znearest30d1 1 QC0.09 [0.09, 0.09]0.00-0.09 [-0.09, -0.09]0.09 [0.09, 0.09]100% [100%, 100%]100%100%+0.97—2026-08-30 → 2026-08-30
tmin00Znearest90d1 1 QC0.09 [0.09, 0.09]0.00-0.09 [-0.09, -0.09]0.09 [0.09, 0.09]100% [100%, 100%]100%100%+0.97—2026-08-30 → 2026-08-30
tmin00Znearest365d1 1 QC0.09 [0.09, 0.09]0.00-0.09 [-0.09, -0.09]0.09 [0.09, 0.09]100% [100%, 100%]100%100%+0.97—2026-08-30 → 2026-08-30
tmin00Znearestall1 1 QC0.09 [0.09, 0.09]0.00-0.09 [-0.09, -0.09]0.09 [0.09, 0.09]100% [100%, 100%]100%100%+0.97—2026-08-30 → 2026-08-30
tmin12Zbilinear30d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin12Zbilinear90d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin12Zbilinear365d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin12Zbilinearall1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%+0.87—2026-08-30 → 2026-08-30
tmin12Znearest30d1 1 QC0.01 [0.01, 0.01]0.00+0.01 [0.01, 0.01]0.01 [0.01, 0.01]100% [100%, 100%]100%100%+1.00—2026-08-30 → 2026-08-30
tmin12Znearest90d1 1 QC0.01 [0.01, 0.01]0.00+0.01 [0.01, 0.01]0.01 [0.01, 0.01]100% [100%, 100%]100%100%+1.00—2026-08-30 → 2026-08-30
tmin12Znearest365d1 1 QC0.01 [0.01, 0.01]0.00+0.01 [0.01, 0.01]0.01 [0.01, 0.01]100% [100%, 100%]100%100%+1.00—2026-08-30 → 2026-08-30
tmin12Znearestall1 1 QC0.01 [0.01, 0.01]0.00+0.01 [0.01, 0.01]0.01 [0.01, 0.01]100% [100%, 100%]100%100%+1.00—2026-08-30 → 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 Aurora (IFS init) at KORD, lead day 2, 00Z bilinear tmax+2+10-1-22026-08-30: -1.43 °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
2026-08-30-1.43

Error distribution

Distribution of the signed daily error in °F for Aurora (IFS init) at KORD, lead day 2-2 to -1.8 °F: 0 days-1.8 to -1.6 °F: 0 days-1.6 to -1.4 °F: 1 day-1.4 to -1.2 °F: 0 days-1.2 to -1 °F: 0 days-1 to -0.8 °F: 0 days-0.8 to -0.6 °F: 0 days-0.6 to -0.4 °F: 0 days-0.4 to -0.2 °F: 0 days-0.2 to 0 °F: 0 days0 to 0.2 °F: 0 days0.2 to 0.4 °F: 0 days0.4 to 0.6 °F: 0 days0.6 to 0.8 °F: 0 days0.8 to 1 °F: 0 days1 to 1.2 °F: 0 days1.2 to 1.4 °F: 0 days1.4 to 1.6 °F: 0 days1.6 to 1.8 °F: 0 days1.8 to 2 °F: 0 daysdashed: P50 |e| 1.43 · P90 |e| 1.43 °F-20+2 °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
-2.00-1.800
-1.80-1.600
-1.60-1.401
-1.40-1.200
-1.20-1.000
-1.00-0.800
-0.80-0.600
-0.60-0.400
-0.40-0.200
-0.20+0.000
+0.00+0.200
+0.20+0.400
+0.40+0.600
+0.60+0.800
+0.80+1.000
+1.00+1.200
+1.20+1.400
+1.40+1.600
+1.60+1.800
+1.80+2.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-0811.43 -1.43

Availability

ModelScored period DaysCoverage
Aurora (IFS init)2026-08-30 → 2026-08-30 1
Aurora (IFS init)2026-08-30 → 2026-08-30 1
Aurora (IFS init)2026-08-30 → 2026-08-30 1
Aurora (IFS init)2026-08-30 → 2026-08-30 1

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 1 -0.76 [-0.76, -0.76] yes
FourCastNet v2 (IFS init) 1 +1.41 [1.41, 1.41] yes
NCEP GFS 1 -2.48 [-2.48, -2.48] yes
GraphCast (IFS init) 1 -3.21 [-3.21, -3.21] yes
ECMWF IFS HRES 1 -1.62 [-1.62, -1.62] yes
Pangu-Weather (IFS init) 1 -0.02 [-0.02, -0.02] yes
Persistence (baseline) 1 +0.43 [0.43, 0.43] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KORD (Chicago O'Hare), model aurora_ifs, 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/KORD/model/aurora_ifs/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