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

Newark Liberty · NCEP GFS · lead day 6

KEWR · gfs · 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, 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
tmax00Zbilinear30d24 1 QC3.12 [2.52, 3.69]3.07-0.49 [-1.95, 1.09]3.65 [2.95, 4.21]12% [3%, 24%]38%50%+0.23+0.162026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC3.12 [2.41, 3.71]3.07-0.49 [-1.97, 1.30]3.65 [2.85, 4.23]12% [0%, 25%]38%50%+0.23+0.162026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC3.12 [2.38, 3.77]3.07-0.49 [-2.13, 1.30]3.65 [2.86, 4.30]12% [0%, 26%]38%50%+0.23+0.162026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC3.12 [2.37, 3.80]3.07-0.49 [-2.28, 1.29]3.65 [2.81, 4.28]12% [0%, 26%]38%50%+0.23+0.162026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC3.28 [2.54, 3.97]3.32+0.38 [-1.31, 2.16]3.98 [3.17, 4.58]21% [7%, 38%]29%54%+0.19+0.092026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC3.28 [2.44, 4.06]3.32+0.38 [-1.41, 2.40]3.98 [3.06, 4.63]21% [5%, 43%]29%54%+0.19+0.092026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC3.28 [2.40, 4.13]3.32+0.38 [-1.59, 2.38]3.98 [2.93, 4.69]21% [6%, 42%]29%54%+0.19+0.092026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC3.28 [2.44, 4.10]3.32+0.38 [-1.70, 2.37]3.98 [3.02, 4.64]21% [0%, 43%]29%54%+0.19+0.092026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC3.43 [2.13, 4.69]3.23-1.33 [-3.05, 0.96]4.53 [2.96, 5.87]21% [8%, 41%]46%54%+0.15+0.122026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC3.43 [1.80, 4.72]3.23-1.33 [-3.30, 1.39]4.53 [2.56, 5.87]21% [7%, 50%]46%54%+0.15+0.122026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC3.43 [1.80, 4.88]3.23-1.33 [-3.54, 1.54]4.53 [2.44, 6.16]21% [7%, 46%]46%54%+0.15+0.122026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC3.43 [1.81, 4.94]3.23-1.33 [-3.49, 1.58]4.53 [2.60, 6.16]21% [7%, 47%]46%54%+0.15+0.122026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC3.66 [2.44, 4.90]3.70-0.22 [-2.26, 2.38]4.95 [3.38, 6.28]21% [9%, 29%]46%46%+0.10-0.012026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC3.66 [2.33, 5.14]3.70-0.22 [-2.55, 2.81]4.95 [3.21, 6.40]21% [7%, 29%]46%46%+0.10-0.012026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC3.66 [2.23, 5.17]3.70-0.22 [-2.80, 2.96]4.95 [3.07, 6.63]21% [0%, 29%]46%46%+0.10-0.012026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC3.66 [2.14, 5.23]3.70-0.22 [-2.77, 3.00]4.95 [2.99, 6.69]21% [0%, 29%]46%46%+0.10-0.012026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC4.61 [3.74, 5.59]2.99+3.61 [2.20, 5.14]5.34 [4.24, 6.32]0% [0%, 0%]17%33%-0.33+0.092026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC4.61 [3.67, 5.72]2.99+3.61 [2.24, 5.34]5.34 [4.10, 6.35]0% [0%, 0%]17%33%-0.33+0.092026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC4.61 [3.63, 5.70]2.99+3.61 [2.09, 5.41]5.34 [4.07, 6.40]0% [0%, 0%]17%33%-0.33+0.092026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC4.61 [3.52, 5.75]2.99+3.61 [2.02, 5.61]5.34 [3.93, 6.45]0% [0%, 0%]17%33%-0.33+0.092026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC4.18 [3.18, 5.20]3.19+2.84 [1.37, 4.46]5.04 [3.89, 6.02]17% [4%, 33%]21%29%-0.21+0.032026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC4.18 [3.14, 5.30]3.19+2.84 [1.40, 4.71]5.04 [3.72, 6.06]17% [0%, 35%]21%29%-0.21+0.032026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC4.18 [3.07, 5.27]3.19+2.84 [1.28, 4.81]5.04 [3.68, 6.08]17% [0%, 36%]21%29%-0.21+0.032026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC4.18 [3.03, 5.33]3.19+2.84 [1.23, 5.04]5.04 [3.59, 6.12]17% [0%, 35%]21%29%-0.21+0.032026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC4.23 [2.94, 5.94]3.35+3.63 [1.93, 5.82]5.37 [4.01, 6.71]17% [0%, 30%]38%46%-0.22-0.022026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC4.23 [2.84, 6.48]3.35+3.63 [1.96, 6.48]5.37 [3.93, 7.07]17% [0%, 30%]38%46%-0.22-0.022026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC4.23 [2.73, 6.51]3.35+3.63 [1.71, 6.51]5.37 [3.74, 7.04]17% [0%, 33%]38%46%-0.22-0.022026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC4.23 [2.76, 6.70]3.35+3.63 [1.69, 6.70]5.37 [3.66, 7.09]17% [0%, 30%]38%46%-0.22-0.022026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC3.92 [2.78, 5.53]3.53+2.80 [0.96, 5.22]4.98 [3.71, 6.31]12% [0%, 23%]33%54%-0.13-0.082026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC3.92 [2.66, 6.10]3.53+2.80 [1.02, 6.10]4.98 [3.58, 6.65]12% [0%, 24%]33%54%-0.13-0.082026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC3.92 [2.61, 6.09]3.53+2.80 [0.67, 6.09]4.98 [3.45, 6.59]12% [0%, 24%]33%54%-0.13-0.082026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC3.92 [2.60, 6.22]3.53+2.80 [0.73, 6.22]4.98 [3.46, 6.69]12% [0%, 25%]33%54%-0.13-0.082026-08-07 → 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 NCEP GFS at KEWR, lead day 6, 00Z bilinear tmax+10+50-5-102026-08-07: -1.62 °F2026-08-08: +2.55 °F2026-08-09: +0.79 °F2026-08-10: +5.16 °F2026-08-11: +3.72 °F2026-08-12: -4.62 °F2026-08-13: -5.43 °F2026-08-14: +0.61 °F2026-08-15: -6.87 °F2026-08-16: -3.79 °F2026-08-17: -3.02 °F2026-08-18: -2.7 °F2026-08-19: -1.03 °F2026-08-20: +6.64 °F2026-08-21: +1.18 °F2026-08-22: -4.24 °F2026-08-23: +3.55 °F2026-08-24: -1.85 °F2026-08-25: +1.6 °F2026-08-26: -3.89 °F2026-08-27: -2.36 °F2026-08-28: -1.71 °F2026-08-29: -0.1 °F2026-08-30: +5.73 °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+5.73
2026-08-29-0.10
2026-08-28-1.71
2026-08-27-2.36
2026-08-26-3.89
2026-08-25+1.60
2026-08-24-1.85
2026-08-23+3.55
2026-08-22-4.24
2026-08-21+1.18
2026-08-20+6.64
2026-08-19-1.03
2026-08-18-2.70
2026-08-17-3.02
2026-08-16-3.79
2026-08-15-6.87
2026-08-14+0.61
2026-08-13-5.43
2026-08-12-4.62
2026-08-11+3.72
2026-08-10+5.16
2026-08-09+0.79
2026-08-08+2.55
2026-08-07-1.62

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KEWR, lead day 6-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 1 day-5 to -4 °F: 2 days-4 to -3 °F: 3 days-3 to -2 °F: 2 days-2 to -1 °F: 4 days-1 to 0 °F: 1 day0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 2 days4 to 5 °F: 0 days5 to 6 °F: 2 days6 to 7 °F: 1 day7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.86 · P90 |e| 5.64 °F-100+10 °Fn = 24 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
-9.00-8.000
-8.00-7.000
-7.00-6.001
-6.00-5.001
-5.00-4.002
-4.00-3.003
-3.00-2.002
-2.00-1.004
-1.00+0.001
+0.00+1.002
+1.00+2.002
+2.00+3.001
+3.00+4.002
+4.00+5.000
+5.00+6.002
+6.00+7.001
+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
2026-08243.12 -0.49

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24

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 24 -0.04 [-1.01, 0.92] no
GraphCast (IFS init) 24 -1.26 [-2.81, 0.00] no
ECMWF IFS HRES 19 -1.05 [-3.02, 0.01] no
Persistence (baseline) 24 -0.93 [-2.23, 0.13] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KEWR (Newark Liberty), model gfs, 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/KEWR/model/gfs/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