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 2

KEWR · gfs · 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, 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
tmax00Zbilinear30d28 1 QC2.93 [2.18, 3.87]2.71-1.81 [-2.89, -0.51]4.36 [2.93, 5.76]25% [7%, 42%]50%75%+0.04+0.102026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC2.93 [2.17, 4.08]2.71-1.81 [-3.39, 0.04]4.36 [2.86, 6.20]25% [3%, 43%]50%75%+0.04+0.102026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC2.93 [2.16, 4.04]2.71-1.81 [-3.47, 0.22]4.36 [2.69, 6.13]25% [0%, 43%]50%75%+0.04+0.102026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC2.93 [2.12, 4.39]2.71-1.81 [-3.64, -0.05]4.36 [2.72, 6.52]25% [0%, 43%]50%75%+0.04+0.102026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC3.15 [2.32, 4.21]3.28-0.93 [-2.13, 0.55]4.78 [3.39, 6.17]29% [14%, 43%]57%68%-0.03-0.092026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC3.15 [2.36, 4.34]3.28-0.93 [-2.57, 1.28]4.78 [3.44, 6.48]29% [14%, 41%]57%68%-0.03-0.092026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC3.15 [2.30, 4.44]3.28-0.93 [-2.55, 1.53]4.78 [3.29, 6.44]29% [12%, 43%]57%68%-0.03-0.092026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC3.15 [2.29, 4.64]3.28-0.93 [-2.76, 1.08]4.78 [3.24, 6.91]29% [11%, 43%]57%68%-0.03-0.092026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC2.37 [1.41, 3.58]2.34-1.40 [-2.45, -0.41]3.76 [1.96, 5.49]39% [27%, 50%]61%71%+0.23+0.222026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC2.37 [1.43, 3.81]2.34-1.40 [-2.85, -0.05]3.76 [2.02, 5.85]39% [24%, 50%]61%71%+0.23+0.222026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC2.37 [1.32, 3.78]2.34-1.40 [-2.83, 0.07]3.76 [1.91, 5.87]39% [25%, 52%]61%71%+0.23+0.222026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC2.37 [1.32, 4.22]2.34-1.40 [-3.03, -0.04]3.76 [1.83, 6.33]39% [22%, 50%]61%71%+0.23+0.222026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC2.77 [1.90, 4.00]2.87-0.50 [-1.86, 0.77]4.18 [2.38, 5.99]25% [11%, 38%]57%68%+0.10+0.052026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC2.77 [1.93, 4.23]2.87-0.50 [-2.19, 1.19]4.18 [2.46, 6.40]25% [11%, 38%]57%68%+0.10+0.052026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC2.77 [1.84, 4.23]2.87-0.50 [-2.29, 1.31]4.18 [2.31, 6.36]25% [10%, 40%]57%68%+0.10+0.052026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC2.77 [1.81, 4.57]2.87-0.50 [-2.54, 1.25]4.18 [2.28, 6.80]25% [9%, 41%]57%68%+0.10+0.052026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC3.64 [3.20, 4.12]2.31+3.05 [2.24, 3.86]4.21 [3.68, 4.69]11% [0%, 25%]21%46%+0.16+0.462026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC3.64 [3.19, 4.20]2.31+3.05 [2.29, 3.96]4.21 [3.62, 4.79]11% [0%, 26%]21%46%+0.16+0.462026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC3.64 [3.20, 4.24]2.31+3.05 [2.16, 4.01]4.21 [3.60, 4.79]11% [0%, 29%]21%46%+0.16+0.462026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC3.64 [3.18, 4.15]2.31+3.05 [2.23, 3.96]4.21 [3.62, 4.76]11% [0%, 28%]21%46%+0.16+0.462026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC3.08 [2.63, 3.50]2.33+2.04 [1.26, 2.83]3.58 [3.05, 3.99]14% [4%, 24%]32%50%+0.29+0.462026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC3.08 [2.59, 3.59]2.33+2.04 [1.27, 2.94]3.58 [2.95, 4.07]14% [0%, 24%]32%50%+0.29+0.462026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC3.08 [2.58, 3.62]2.33+2.04 [1.18, 3.01]3.58 [2.95, 4.12]14% [0%, 24%]32%50%+0.29+0.462026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC3.08 [2.60, 3.62]2.33+2.04 [1.18, 2.91]3.58 [2.97, 4.05]14% [0%, 24%]32%50%+0.29+0.462026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC3.47 [2.87, 4.09]2.37+3.05 [2.37, 3.76]4.22 [3.47, 4.87]11% [0%, 25%]36%57%+0.20+0.452026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC3.47 [2.94, 4.11]2.37+3.05 [2.46, 3.76]4.22 [3.50, 4.85]11% [0%, 24%]36%57%+0.20+0.452026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC3.47 [2.85, 4.18]2.37+3.05 [2.32, 3.89]4.22 [3.32, 4.93]11% [0%, 27%]36%57%+0.20+0.452026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC3.47 [2.82, 4.18]2.37+3.05 [2.34, 3.86]4.22 [3.22, 4.87]11% [0%, 24%]36%57%+0.20+0.452026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC2.72 [2.08, 3.33]2.44+1.97 [1.27, 2.70]3.51 [2.78, 4.08]36% [19%, 52%]46%57%+0.37+0.432026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC2.72 [2.06, 3.36]2.44+1.97 [1.39, 2.70]3.51 [2.81, 4.07]36% [17%, 53%]46%57%+0.37+0.432026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC2.72 [2.00, 3.40]2.44+1.97 [1.26, 2.82]3.51 [2.62, 4.11]36% [18%, 56%]46%57%+0.37+0.432026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC2.72 [1.96, 3.41]2.44+1.97 [1.25, 2.78]3.51 [2.59, 4.09]36% [14%, 55%]46%57%+0.37+0.432026-08-03 → 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 2, 00Z bilinear tmax+20+100-10-202026-08-03: -14.03 °F2026-08-04: -0.69 °F2026-08-05: -2.19 °F2026-08-06: -3.01 °F2026-08-07: -0.85 °F2026-08-08: -0.14 °F2026-08-09: +0.97 °F2026-08-10: +2.39 °F2026-08-11: +1.33 °F2026-08-12: -2.28 °F2026-08-13: -11.24 °F2026-08-14: -0.99 °F2026-08-15: -2.32 °F2026-08-16: -3.28 °F2026-08-17: +0.78 °F2026-08-18: -2.28 °F2026-08-19: +0.23 °F2026-08-20: -7.55 °F2026-08-21: +1.18 °F2026-08-22: -7.35 °F2026-08-23: -1.35 °F2026-08-24: -2.24 °F2026-08-25: -1.77 °F2026-08-26: -1.78 °F2026-08-27: +1.52 °F2026-08-28: -1.02 °F2026-08-29: +2.69 °F2026-08-30: +4.7 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+4.70
2026-08-29+2.69
2026-08-28-1.02
2026-08-27+1.52
2026-08-26-1.78
2026-08-25-1.77
2026-08-24-2.24
2026-08-23-1.35
2026-08-22-7.35
2026-08-21+1.18
2026-08-20-7.55
2026-08-19+0.23
2026-08-18-2.28
2026-08-17+0.78
2026-08-16-3.28
2026-08-15-2.32
2026-08-14-0.99
2026-08-13-11.24
2026-08-12-2.28
2026-08-11+1.33
2026-08-10+2.39
2026-08-09+0.97
2026-08-08-0.14
2026-08-07-0.85
2026-08-06-3.01
2026-08-05-2.19
2026-08-04-0.69
2026-08-03-14.03

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KEWR, lead day 2-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 0 days-8 to -6 °F: 2 days-6 to -4 °F: 0 days-4 to -2 °F: 7 days-2 to 0 °F: 8 days0 to 2 °F: 6 days2 to 4 °F: 2 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| 1.98 · P90 |e| 7.41 °F-200+20 °Fn = 28 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
-16.00-14.001
-14.00-12.000
-12.00-10.001
-10.00-8.000
-8.00-6.002
-6.00-4.000
-4.00-2.007
-2.00+0.008
+0.00+2.006
+2.00+4.002
+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
2026-08282.93 -1.81

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28

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 28 -0.16 [-1.23, 1.18] no
Aurora (IFS init) 1 +4.15 [4.15, 4.15] yes
FourCastNet v2 (IFS init) 1 +2.61 [2.61, 2.61] yes
GraphCast (IFS init) 26 -1.77 [-2.88, -0.10] yes
ECMWF IFS HRES 22 -0.54 [-2.02, 1.98] no
Pangu-Weather (IFS init) 1 +3.31 [3.31, 3.31] yes
Persistence (baseline) 28 -0.14 [-1.61, 1.34] no

Cite this page

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

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