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

Newark Liberty · GraphCast (IFS init) · lead day 5

KEWR · graphcast_ifs · lead 5

Target day = initialization date + 5 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, 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
tmax00Zbilinear30d25 1 QC4.36 [3.60, 5.22]2.40-4.20 [-5.21, -3.20]5.11 [4.32, 5.91]8% [0%, 19%]28%36%-0.12+0.372026-08-06 → 2026-08-30
tmax00Zbilinear90d25 1 QC4.36 [3.41, 5.36]2.40-4.20 [-5.33, -2.94]5.11 [4.20, 6.01]8% [0%, 22%]28%36%-0.12+0.372026-08-06 → 2026-08-30
tmax00Zbilinear365d31 1 QC4.24 [3.41, 5.07]2.70-3.70 [-4.98, -2.14]5.02 [4.21, 5.79]10% [0%, 22%]29%39%+0.30+0.572026-01-06 → 2026-08-30
tmax00Zbilinearall31 1 QC4.24 [3.43, 5.01]2.70-3.70 [-4.88, -2.20]5.02 [4.21, 5.74]10% [0%, 22%]29%39%+0.30+0.572026-01-06 → 2026-08-30
tmax00Znearest30d25 1 QC3.94 [3.39, 4.58]2.45-3.63 [-4.49, -2.65]4.67 [4.06, 5.29]16% [8%, 23%]32%36%-0.02+0.352026-08-06 → 2026-08-30
tmax00Znearest90d25 1 QC3.94 [3.36, 4.64]2.45-3.63 [-4.59, -2.42]4.67 [3.99, 5.33]16% [8%, 24%]32%36%-0.02+0.352026-08-06 → 2026-08-30
tmax00Znearest365d31 1 QC3.91 [3.38, 4.48]2.73-3.15 [-4.25, -1.63]4.67 [4.07, 5.25]16% [9%, 25%]32%42%+0.35+0.572026-01-06 → 2026-08-30
tmax00Znearestall31 1 QC3.91 [3.38, 4.45]2.73-3.15 [-4.18, -1.66]4.67 [4.05, 5.20]16% [8%, 23%]32%42%+0.35+0.572026-01-06 → 2026-08-30
tmax12Zbilinear30d25 1 QC4.84 [3.74, 6.24]2.82-4.75 [-6.20, -3.63]5.87 [4.46, 7.28]8% [0%, 27%]28%36%-0.25+0.262026-08-06 → 2026-08-30
tmax12Zbilinear90d25 1 QC4.84 [3.65, 6.63]2.82-4.75 [-6.60, -3.48]5.87 [4.34, 7.55]8% [0%, 33%]28%36%-0.25+0.262026-08-06 → 2026-08-30
tmax12Zbilinear365d30 1 QC4.53 [3.29, 5.81]2.86-4.37 [-5.68, -2.90]5.58 [4.07, 6.86]10% [0%, 30%]33%40%+0.25+0.552026-01-06 → 2026-08-30
tmax12Zbilinearall30 1 QC4.53 [3.27, 5.87]2.86-4.37 [-5.78, -2.92]5.58 [3.91, 6.97]10% [0%, 31%]33%40%+0.25+0.552026-01-06 → 2026-08-30
tmax12Znearest30d25 1 QC4.43 [3.40, 5.84]2.90-4.22 [-5.52, -3.17]5.50 [4.17, 6.82]16% [4%, 28%]32%44%-0.14+0.232026-08-06 → 2026-08-30
tmax12Znearest90d25 1 QC4.43 [3.29, 5.97]2.90-4.22 [-5.91, -2.99]5.50 [3.95, 7.01]16% [0%, 29%]32%44%-0.14+0.232026-08-06 → 2026-08-30
tmax12Znearest365d30 1 QC4.16 [3.07, 5.28]2.93-3.83 [-5.12, -2.36]5.22 [3.74, 6.39]17% [5%, 28%]33%47%+0.31+0.532026-01-06 → 2026-08-30
tmax12Znearestall30 1 QC4.16 [3.04, 5.36]2.93-3.83 [-5.16, -2.34]5.22 [3.63, 6.46]17% [3%, 28%]33%47%+0.31+0.532026-01-06 → 2026-08-30
tmin00Zbilinear30d25 1 QC2.69 [2.33, 3.10]2.40+1.07 [-0.08, 2.17]3.18 [2.65, 3.65]4% [0%, 12%]44%68%+0.08+0.162026-08-06 → 2026-08-30
tmin00Zbilinear90d25 1 QC2.69 [2.30, 3.21]2.40+1.07 [-0.11, 2.39]3.18 [2.60, 3.75]4% [0%, 12%]44%68%+0.08+0.162026-08-06 → 2026-08-30
tmin00Zbilinear365d31 1 QC2.78 [2.27, 3.38]2.65+0.93 [-0.17, 2.13]3.65 [2.73, 4.71]16% [0%, 42%]48%68%+0.42+0.482026-01-06 → 2026-08-30
tmin00Zbilinearall31 1 QC2.78 [2.30, 3.31]2.65+0.93 [-0.37, 2.16]3.65 [2.78, 4.75]16% [0%, 44%]48%68%+0.42+0.482026-01-06 → 2026-08-30
tmin00Znearest30d25 1 QC2.58 [2.16, 2.98]2.55+0.17 [-1.08, 1.40]3.16 [2.60, 3.54]12% [0%, 23%]48%68%+0.12+0.102026-08-06 → 2026-08-30
tmin00Znearest90d25 1 QC2.58 [2.10, 3.02]2.55+0.17 [-1.11, 1.54]3.16 [2.51, 3.55]12% [0%, 24%]48%68%+0.12+0.102026-08-06 → 2026-08-30
tmin00Znearest365d31 1 QC2.79 [2.22, 3.49]2.79+0.06 [-1.10, 1.27]3.70 [2.73, 4.75]16% [4%, 29%]52%68%+0.42+0.452026-01-06 → 2026-08-30
tmin00Znearestall31 1 QC2.79 [2.20, 3.48]2.79+0.06 [-1.29, 1.32]3.70 [2.79, 4.89]16% [4%, 30%]52%68%+0.42+0.452026-01-06 → 2026-08-30
tmin12Zbilinear30d25 1 QC2.82 [2.20, 3.31]2.72+0.91 [-0.14, 2.03]3.44 [2.60, 4.06]16% [7%, 24%]36%64%+0.03+0.042026-08-06 → 2026-08-30
tmin12Zbilinear90d25 1 QC2.82 [2.15, 3.36]2.72+0.91 [-0.20, 2.12]3.44 [2.48, 4.13]16% [5%, 24%]36%64%+0.03+0.042026-08-06 → 2026-08-30
tmin12Zbilinear365d30 1 QC2.91 [2.25, 3.55]2.80+0.98 [-0.04, 2.17]3.60 [2.71, 4.31]20% [9%, 33%]37%60%+0.40+0.462026-01-06 → 2026-08-30
tmin12Zbilinearall30 1 QC2.91 [2.26, 3.48]2.80+0.98 [-0.20, 2.23]3.60 [2.73, 4.28]20% [9%, 33%]37%60%+0.40+0.462026-01-06 → 2026-08-30
tmin12Znearest30d25 1 QC2.81 [2.08, 3.51]2.82+0.02 [-1.02, 1.07]3.46 [2.55, 4.09]20% [8%, 33%]44%60%+0.04+0.012026-08-06 → 2026-08-30
tmin12Znearest90d25 1 QC2.81 [1.99, 3.49]2.82+0.02 [-1.06, 1.18]3.46 [2.43, 4.09]20% [7%, 38%]44%60%+0.04+0.012026-08-06 → 2026-08-30
tmin12Znearest365d30 1 QC2.91 [2.17, 3.60]2.92+0.14 [-0.83, 1.33]3.64 [2.72, 4.35]20% [9%, 33%]43%60%+0.40+0.442026-01-06 → 2026-08-30
tmin12Znearestall30 1 QC2.91 [2.19, 3.62]2.92+0.14 [-1.04, 1.32]3.64 [2.72, 4.32]20% [8%, 33%]43%60%+0.40+0.442026-01-06 → 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 KEWR, lead day 5, 00Z bilinear tmax+20+100-10-202026-08-06: -6.16 °F2026-08-07: -7.65 °F2026-08-08: -6.45 °F2026-08-09: -5.68 °F2026-08-10: -1.97 °F2026-08-11: -1.63 °F2026-08-12: -10.77 °F2026-08-13: -2.05 °F2026-08-14: -4.1 °F2026-08-15: -7.77 °F2026-08-16: -3.43 °F2026-08-17: -1.22 °F2026-08-18: -5.33 °F2026-08-19: -6.96 °F2026-08-20: -3.79 °F2026-08-21: -4.61 °F2026-08-22: -0.02 °F2026-08-23: -2.58 °F2026-08-24: -4.69 °F2026-08-25: -5.66 °F2026-08-26: -5.02 °F2026-08-27: -1.57 °F2026-08-28: -7.85 °F2026-08-29: +1.3 °F2026-08-30: +0.75 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.75
2026-08-29+1.30
2026-08-28-7.85
2026-08-27-1.57
2026-08-26-5.02
2026-08-25-5.66
2026-08-24-4.69
2026-08-23-2.58
2026-08-22-0.02
2026-08-21-4.61
2026-08-20-3.79
2026-08-19-6.96
2026-08-18-5.33
2026-08-17-1.22
2026-08-16-3.43
2026-08-15-7.77
2026-08-14-4.10
2026-08-13-2.05
2026-08-12-10.77
2026-08-11-1.63
2026-08-10-1.97
2026-08-09-5.68
2026-08-08-6.45
2026-08-07-7.65
2026-08-06-6.16

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KEWR, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 6 days-6 to -4 °F: 7 days-4 to -2 °F: 6 days-2 to 0 °F: 6 days0 to 2 °F: 3 days2 to 4 °F: 0 days4 to 6 °F: 1 day6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.1 · P90 |e| 7.77 °F-200+20 °Fn = 31 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.001
-8.00-6.006
-6.00-4.007
-4.00-2.006
-2.00+0.006
+0.00+2.003
+2.00+4.000
+4.00+6.001
+6.00+8.000
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08254.36 -4.20
2026-0163.74 -1.65

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 30
GraphCast (IFS init)2026-01-06 → 2026-08-30 30

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 25 +0.78 [-0.10, 1.69] no
NCEP GFS 25 +0.81 [-0.61, 2.31] no
ECMWF IFS HRES 18 +0.33 [-0.74, 1.59] no
Persistence (baseline) 25 +0.48 [-0.47, 1.36] no

Cite this page

ShortCastCheck, KEWR graphcast_ifs lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KEWR/model/graphcast_ifs/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KEWR (Newark Liberty), model graphcast_ifs, lead day 5. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KEWR/model/graphcast_ifs/lead/5/

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