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

Newark Liberty · NCEP GFS · lead day 8

KEWR · gfs · lead 8

Target day = initialization date + 8 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, 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
tmax00Zbilinear30d22 1 QC3.56 [2.82, 4.16]3.17-2.03 [-3.39, -0.61]4.43 [3.42, 5.19]18% [0%, 41%]36%41%+0.18+0.202026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC3.56 [2.62, 4.12]3.17-2.03 [-3.29, -0.30]4.43 [3.23, 5.20]18% [0%, 47%]36%41%+0.18+0.202026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC3.56 [2.66, 4.20]3.17-2.03 [-3.37, -0.32]4.43 [3.18, 5.24]18% [0%, 46%]36%41%+0.18+0.202026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC3.56 [2.76, 4.19]3.17-2.03 [-3.46, -0.12]4.43 [3.21, 5.27]18% [0%, 46%]36%41%+0.18+0.202026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC3.45 [2.47, 4.18]3.34-0.90 [-2.28, 0.63]4.33 [2.97, 5.24]9% [0%, 17%]32%50%+0.21+0.152026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC3.45 [2.23, 4.36]3.34-0.90 [-2.24, 1.04]4.33 [2.78, 5.42]9% [0%, 17%]32%50%+0.21+0.152026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC3.45 [2.16, 4.34]3.34-0.90 [-2.28, 0.79]4.33 [2.75, 5.42]9% [0%, 17%]32%50%+0.21+0.152026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC3.45 [2.03, 4.36]3.34-0.90 [-2.57, 0.99]4.33 [2.64, 5.39]9% [0%, 17%]32%50%+0.21+0.152026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC3.31 [2.62, 4.43]3.21-0.55 [-1.98, 1.44]4.12 [3.40, 4.93]18% [0%, 29%]41%55%+0.24+0.192026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC3.31 [2.50, 4.89]3.21-0.55 [-2.01, 1.60]4.12 [3.23, 5.23]18% [0%, 29%]41%55%+0.24+0.192026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC3.31 [2.45, 4.99]3.21-0.55 [-2.08, 1.60]4.12 [3.30, 5.22]18% [0%, 29%]41%55%+0.24+0.192026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC3.31 [2.52, 5.18]3.21-0.55 [-2.15, 1.99]4.12 [3.34, 5.28]18% [0%, 29%]41%55%+0.24+0.192026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC3.82 [3.06, 4.91]3.75+0.74 [-0.98, 2.91]4.62 [3.64, 5.55]14% [0%, 25%]27%45%+0.13+0.052026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC3.82 [3.07, 5.35]3.75+0.74 [-0.95, 3.26]4.62 [3.52, 5.74]14% [0%, 25%]27%45%+0.13+0.052026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC3.82 [3.04, 5.27]3.75+0.74 [-1.17, 3.34]4.62 [3.46, 5.72]14% [0%, 29%]27%45%+0.13+0.052026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC3.82 [3.04, 5.49]3.75+0.74 [-1.10, 3.48]4.62 [3.52, 5.77]14% [0%, 25%]27%45%+0.13+0.052026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC4.47 [3.46, 5.64]3.27+3.53 [1.65, 5.35]5.39 [4.14, 6.54]18% [7%, 28%]23%36%+0.06+0.252026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC4.47 [3.39, 5.74]3.27+3.53 [1.70, 5.48]5.39 [4.10, 6.57]18% [0%, 29%]23%36%+0.06+0.252026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC4.47 [3.38, 5.87]3.27+3.53 [1.45, 5.50]5.39 [4.01, 6.72]18% [0%, 29%]23%36%+0.06+0.252026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC4.47 [3.22, 6.05]3.27+3.53 [1.33, 5.86]5.39 [3.85, 6.90]18% [0%, 29%]23%36%+0.06+0.252026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC3.93 [2.93, 5.06]3.35+2.67 [0.82, 4.48]4.87 [3.67, 5.90]18% [0%, 43%]36%45%+0.17+0.232026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC3.93 [2.84, 5.13]3.35+2.67 [0.85, 4.61]4.87 [3.67, 5.92]18% [0%, 50%]36%45%+0.17+0.232026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC3.93 [2.81, 5.28]3.35+2.67 [0.59, 4.71]4.87 [3.65, 6.08]18% [0%, 50%]36%45%+0.17+0.232026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC3.93 [2.72, 5.49]3.35+2.67 [0.48, 4.95]4.87 [3.42, 6.25]18% [0%, 56%]36%45%+0.17+0.232026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC4.64 [3.52, 5.86]3.97+3.53 [1.44, 5.70]5.68 [4.42, 6.82]14% [0%, 28%]27%50%+0.02+0.092026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC4.64 [3.47, 5.94]3.97+3.53 [1.37, 5.80]5.68 [4.28, 6.90]14% [0%, 29%]27%50%+0.02+0.092026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC4.64 [3.42, 6.14]3.97+3.53 [0.98, 5.93]5.68 [4.24, 7.03]14% [0%, 31%]27%50%+0.02+0.092026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC4.64 [3.44, 6.27]3.97+3.53 [1.10, 6.26]5.68 [4.24, 7.07]14% [0%, 31%]27%50%+0.02+0.092026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC4.36 [3.52, 5.29]3.97+2.55 [0.54, 4.62]5.14 [4.17, 6.12]14% [0%, 31%]27%32%+0.08+0.092026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC4.36 [3.51, 5.41]3.97+2.55 [0.41, 4.73]5.14 [4.06, 6.20]14% [0%, 33%]27%32%+0.08+0.092026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC4.36 [3.54, 5.37]3.97+2.55 [0.08, 4.93]5.14 [4.09, 6.23]14% [0%, 33%]27%32%+0.08+0.092026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC4.36 [3.52, 5.31]3.97+2.55 [0.13, 5.27]5.14 [4.11, 6.21]14% [0%, 33%]27%32%+0.08+0.092026-08-09 → 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 KEWR, lead day 8, 00Z bilinear tmax+20+100-10-202026-08-09: +3.05 °F2026-08-10: -0.9 °F2026-08-11: +0.61 °F2026-08-12: -6.93 °F2026-08-13: -10.61 °F2026-08-14: -0.21 °F2026-08-15: -3.23 °F2026-08-16: +0.06 °F2026-08-17: -3.89 °F2026-08-18: -5.29 °F2026-08-19: -6.02 °F2026-08-20: +5.95 °F2026-08-21: -2.46 °F2026-08-22: +4.86 °F2026-08-23: -3.6 °F2026-08-24: +1.18 °F2026-08-25: -2 °F2026-08-26: -4.76 °F2026-08-27: -1.21 °F2026-08-28: -7.14 °F2026-08-29: +1.1 °F2026-08-30: -3.24 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.24
2026-08-29+1.10
2026-08-28-7.14
2026-08-27-1.21
2026-08-26-4.76
2026-08-25-2.00
2026-08-24+1.18
2026-08-23-3.60
2026-08-22+4.86
2026-08-21-2.46
2026-08-20+5.95
2026-08-19-6.02
2026-08-18-5.29
2026-08-17-3.89
2026-08-16+0.06
2026-08-15-3.23
2026-08-14-0.21
2026-08-13-10.61
2026-08-12-6.93
2026-08-11+0.61
2026-08-10-0.90
2026-08-09+3.05

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KEWR, lead day 8-20 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: 0 days-8 to -6 °F: 3 days-6 to -4 °F: 2 days-4 to -2 °F: 5 days-2 to 0 °F: 4 days0 to 2 °F: 4 days2 to 4 °F: 1 day4 to 6 °F: 2 days6 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| 3.23 · P90 |e| 6.84 °F-200+20 °Fn = 22 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
-10.00-8.000
-8.00-6.003
-6.00-4.002
-4.00-2.005
-2.00+0.004
+0.00+2.004
+2.00+4.001
+4.00+6.002
+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
2026-08223.56 -2.03

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22

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 22 -0.75 [-2.24, 0.66] no
GraphCast (IFS init) 22 -1.04 [-3.28, 0.04] no
ECMWF IFS HRES 17 -0.02 [-2.79, 0.86] no
Persistence (baseline) 22 -0.81 [-2.02, 0.45] no

Cite this page

ShortCastCheck, KEWR gfs lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KEWR/model/gfs/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KEWR (Newark Liberty), model gfs, lead day 8. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KEWR/model/gfs/lead/8/

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