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 9

KEWR · gfs · lead 9

Target day = initialization date + 9 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
tmax00Zbilinear30d21 1 QC4.91 [3.80, 5.84]4.95-0.77 [-2.97, 1.60]5.93 [4.71, 6.79]10% [0%, 20%]24%38%-0.20-0.462026-08-10 → 2026-08-30
tmax00Zbilinear90d21 1 QC4.91 [3.57, 5.90]4.95-0.77 [-3.26, 2.08]5.93 [4.40, 6.91]10% [0%, 22%]24%38%-0.20-0.462026-08-10 → 2026-08-30
tmax00Zbilinear365d21 1 QC4.91 [3.61, 6.01]4.95-0.77 [-3.28, 1.97]5.93 [4.37, 6.97]10% [0%, 22%]24%38%-0.20-0.462026-08-10 → 2026-08-30
tmax00Zbilinearall21 1 QC4.91 [3.56, 5.98]4.95-0.77 [-3.28, 2.31]5.93 [4.41, 6.97]10% [0%, 22%]24%38%-0.20-0.462026-08-10 → 2026-08-30
tmax00Znearest30d21 1 QC5.63 [4.39, 6.72]5.62+0.08 [-2.17, 2.58]6.48 [5.06, 7.54]0% [0%, 0%]14%24%-0.38-0.662026-08-10 → 2026-08-30
tmax00Znearest90d21 1 QC5.63 [4.27, 6.77]5.62+0.08 [-2.54, 2.91]6.48 [4.89, 7.56]0% [0%, 0%]14%24%-0.38-0.662026-08-10 → 2026-08-30
tmax00Znearest365d21 1 QC5.63 [4.28, 6.77]5.62+0.08 [-2.54, 2.83]6.48 [4.86, 7.58]0% [0%, 0%]14%24%-0.38-0.662026-08-10 → 2026-08-30
tmax00Znearestall21 1 QC5.63 [4.22, 6.77]5.62+0.08 [-2.54, 3.37]6.48 [4.80, 7.56]0% [0%, 0%]14%24%-0.38-0.662026-08-10 → 2026-08-30
tmax12Zbilinear30d21 1 QC4.97 [3.57, 6.45]4.91-0.46 [-2.64, 2.20]6.43 [4.32, 8.30]0% [0%, 0%]29%38%-0.21-0.452026-08-10 → 2026-08-30
tmax12Zbilinear90d21 1 QC4.97 [3.51, 6.50]4.91-0.46 [-2.93, 2.54]6.43 [4.21, 8.39]0% [0%, 0%]29%38%-0.21-0.452026-08-10 → 2026-08-30
tmax12Zbilinear365d21 1 QC4.97 [3.42, 6.58]4.91-0.46 [-2.95, 2.76]6.43 [4.09, 8.52]0% [0%, 0%]29%38%-0.21-0.452026-08-10 → 2026-08-30
tmax12Zbilinearall21 1 QC4.97 [3.42, 6.57]4.91-0.46 [-2.82, 2.96]6.43 [4.03, 8.52]0% [0%, 0%]29%38%-0.21-0.452026-08-10 → 2026-08-30
tmax12Znearest30d21 1 QC4.97 [3.32, 6.69]5.06+0.74 [-1.79, 3.68]6.76 [4.24, 9.10]19% [0%, 38%]33%33%-0.21-0.502026-08-10 → 2026-08-30
tmax12Znearest90d21 1 QC4.97 [3.33, 6.71]5.06+0.74 [-2.07, 3.98]6.76 [4.26, 9.11]19% [0%, 36%]33%33%-0.21-0.502026-08-10 → 2026-08-30
tmax12Znearest365d21 1 QC4.97 [3.06, 6.72]5.06+0.74 [-2.07, 4.26]6.76 [3.90, 9.34]19% [0%, 40%]33%33%-0.21-0.502026-08-10 → 2026-08-30
tmax12Znearestall21 1 QC4.97 [3.22, 6.95]5.06+0.74 [-2.05, 4.51]6.76 [4.10, 9.36]19% [0%, 38%]33%33%-0.21-0.502026-08-10 → 2026-08-30
tmin00Zbilinear30d21 1 QC4.90 [3.79, 6.08]3.61+3.08 [0.85, 5.49]5.55 [4.29, 6.69]10% [0%, 18%]10%19%-0.26-0.112026-08-10 → 2026-08-30
tmin00Zbilinear90d21 1 QC4.90 [3.80, 6.23]3.61+3.08 [0.86, 5.78]5.55 [4.30, 6.79]10% [0%, 18%]10%19%-0.26-0.112026-08-10 → 2026-08-30
tmin00Zbilinear365d21 1 QC4.90 [3.77, 6.22]3.61+3.08 [0.75, 5.77]5.55 [4.25, 6.81]10% [0%, 18%]10%19%-0.26-0.112026-08-10 → 2026-08-30
tmin00Zbilinearall21 1 QC4.90 [3.64, 6.49]3.61+3.08 [0.61, 6.40]5.55 [4.02, 6.95]10% [0%, 17%]10%19%-0.26-0.112026-08-10 → 2026-08-30
tmin00Znearest30d21 1 QC4.60 [3.74, 5.51]3.72+2.26 [0.03, 4.70]5.24 [4.23, 6.16]5% [0%, 14%]14%43%-0.18-0.142026-08-10 → 2026-08-30
tmin00Znearest90d21 1 QC4.60 [3.75, 5.62]3.72+2.26 [0.02, 4.99]5.24 [4.25, 6.26]5% [0%, 15%]14%43%-0.18-0.142026-08-10 → 2026-08-30
tmin00Znearest365d21 1 QC4.60 [3.76, 5.68]3.72+2.26 [-0.09, 4.97]5.24 [4.21, 6.28]5% [0%, 14%]14%43%-0.18-0.142026-08-10 → 2026-08-30
tmin00Znearestall21 1 QC4.60 [3.67, 5.79]3.72+2.26 [-0.17, 5.64]5.24 [4.16, 6.38]5% [0%, 15%]14%43%-0.18-0.142026-08-10 → 2026-08-30
tmin12Zbilinear30d21 1 QC4.38 [3.07, 5.83]4.10+3.02 [0.86, 5.29]5.60 [3.96, 6.95]19% [6%, 32%]38%48%-0.12-0.262026-08-10 → 2026-08-30
tmin12Zbilinear90d21 1 QC4.38 [3.05, 5.93]4.10+3.02 [0.53, 5.37]5.60 [3.75, 7.05]19% [0%, 32%]38%48%-0.12-0.262026-08-10 → 2026-08-30
tmin12Zbilinear365d21 1 QC4.38 [2.78, 6.04]4.10+3.02 [0.44, 5.59]5.60 [3.56, 7.19]19% [0%, 33%]38%48%-0.12-0.262026-08-10 → 2026-08-30
tmin12Zbilinearall21 1 QC4.38 [2.99, 6.26]4.10+3.02 [0.49, 5.85]5.60 [3.69, 7.35]19% [0%, 31%]38%48%-0.12-0.262026-08-10 → 2026-08-30
tmin12Znearest30d21 1 QC4.41 [3.20, 5.63]4.31+2.17 [-0.11, 4.50]5.41 [3.93, 6.62]19% [11%, 29%]24%48%-0.13-0.332026-08-10 → 2026-08-30
tmin12Znearest90d21 1 QC4.41 [3.12, 5.72]4.31+2.17 [-0.37, 4.65]5.41 [3.89, 6.72]19% [9%, 29%]24%48%-0.13-0.332026-08-10 → 2026-08-30
tmin12Znearest365d21 1 QC4.41 [2.80, 5.82]4.31+2.17 [-0.48, 4.83]5.41 [3.60, 6.80]19% [10%, 31%]24%48%-0.13-0.332026-08-10 → 2026-08-30
tmin12Znearestall21 1 QC4.41 [3.07, 6.00]4.31+2.17 [-0.42, 5.21]5.41 [3.76, 7.01]19% [10%, 29%]24%48%-0.13-0.332026-08-10 → 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 9, 00Z bilinear tmax+20+100-10-202026-08-10: +2.08 °F2026-08-11: +5.82 °F2026-08-12: +4.57 °F2026-08-13: -6.4 °F2026-08-14: -5.99 °F2026-08-15: -1.4 °F2026-08-16: +0.84 °F2026-08-17: -7.16 °F2026-08-18: -1.23 °F2026-08-19: -11.02 °F2026-08-20: +2.21 °F2026-08-21: -6.32 °F2026-08-22: +10.45 °F2026-08-23: +6.35 °F2026-08-24: +2.25 °F2026-08-25: +6.75 °F2026-08-26: -4.97 °F2026-08-27: -3.2 °F2026-08-28: -11.97 °F2026-08-29: +0.69 °F2026-08-30: +1.43 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.43
2026-08-29+0.69
2026-08-28-11.97
2026-08-27-3.20
2026-08-26-4.97
2026-08-25+6.75
2026-08-24+2.25
2026-08-23+6.35
2026-08-22+10.45
2026-08-21-6.32
2026-08-20+2.21
2026-08-19-11.02
2026-08-18-1.23
2026-08-17-7.16
2026-08-16+0.84
2026-08-15-1.40
2026-08-14-5.99
2026-08-13-6.40
2026-08-12+4.57
2026-08-11+5.82
2026-08-10+2.08

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KEWR, lead day 9-20 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: 2 days-10 to -8 °F: 0 days-8 to -6 °F: 3 days-6 to -4 °F: 2 days-4 to -2 °F: 1 day-2 to 0 °F: 2 days0 to 2 °F: 3 days2 to 4 °F: 3 days4 to 6 °F: 2 days6 to 8 °F: 2 days8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.97 · P90 |e| 10.45 °F-200+20 °Fn = 21 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
-12.00-10.002
-10.00-8.000
-8.00-6.003
-6.00-4.002
-4.00-2.001
-2.00+0.002
+0.00+2.003
+2.00+4.003
+4.00+6.002
+6.00+8.002
+8.00+10.000
+10.00+12.001
+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
2026-08214.91 -0.77

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21

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 21 -0.60 [-2.97, 1.54] no
GraphCast (IFS init) 21 -0.56 [-2.27, 1.09] no
ECMWF IFS HRES 16 +0.48 [-6.52, 2.61] no
Persistence (baseline) 21 +0.82 [-1.17, 2.52] no

Cite this page

ShortCastCheck, KEWR gfs lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KEWR/model/gfs/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KEWR (Newark Liberty), model gfs, lead day 9. 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/9/

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