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

Newark Liberty · ECMWF AIFS Single · lead day 4

KEWR · aifs_single · lead 4

Target day = initialization date + 4 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, aifs-single-gpid5, 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
tmax00Zbilinear30d26 1 QC3.49 [2.92, 4.09]1.77-3.20 [-3.97, -2.44]3.91 [3.42, 4.48]15% [4%, 30%]19%35%+0.14+0.542026-08-05 → 2026-08-30
tmax00Zbilinear90d26 1 QC3.49 [2.79, 4.29]1.77-3.20 [-4.20, -2.29]3.91 [3.31, 4.65]15% [4%, 36%]19%35%+0.14+0.542026-08-05 → 2026-08-30
tmax00Zbilinear365d26 1 QC3.49 [2.69, 4.24]1.77-3.20 [-4.20, -2.22]3.91 [3.18, 4.64]15% [0%, 37%]19%35%+0.14+0.542026-08-05 → 2026-08-30
tmax00Zbilinearall26 1 QC3.49 [2.70, 4.33]1.77-3.20 [-4.19, -2.23]3.91 [3.25, 4.67]15% [0%, 38%]19%35%+0.14+0.542026-08-05 → 2026-08-30
tmax00Znearest30d26 1 QC3.53 [2.97, 4.10]1.73-3.22 [-3.96, -2.44]3.92 [3.45, 4.46]15% [4%, 30%]19%31%+0.13+0.552026-08-05 → 2026-08-30
tmax00Znearest90d26 1 QC3.53 [2.83, 4.26]1.73-3.22 [-4.20, -2.32]3.92 [3.33, 4.61]15% [4%, 36%]19%31%+0.13+0.552026-08-05 → 2026-08-30
tmax00Znearest365d26 1 QC3.53 [2.72, 4.23]1.73-3.22 [-4.16, -2.20]3.92 [3.23, 4.59]15% [0%, 37%]19%31%+0.13+0.552026-08-05 → 2026-08-30
tmax00Znearestall26 1 QC3.53 [2.81, 4.37]1.73-3.22 [-4.22, -2.25]3.92 [3.27, 4.68]15% [0%, 38%]19%31%+0.13+0.552026-08-05 → 2026-08-30
tmax12Zbilinear30d26 1 QC2.93 [2.35, 3.82]1.81-2.65 [-3.70, -1.90]3.47 [2.83, 4.34]15% [5%, 24%]35%58%+0.28+0.522026-08-05 → 2026-08-30
tmax12Zbilinear90d26 1 QC2.93 [2.30, 4.01]1.81-2.65 [-3.97, -1.76]3.47 [2.74, 4.49]15% [0%, 25%]35%58%+0.28+0.522026-08-05 → 2026-08-30
tmax12Zbilinear365d26 1 QC2.93 [2.23, 4.00]1.81-2.65 [-3.88, -1.71]3.47 [2.70, 4.48]15% [0%, 27%]35%58%+0.28+0.522026-08-05 → 2026-08-30
tmax12Zbilinearall26 1 QC2.93 [2.27, 4.04]1.81-2.65 [-3.92, -1.77]3.47 [2.73, 4.53]15% [0%, 26%]35%58%+0.28+0.522026-08-05 → 2026-08-30
tmax12Znearest30d26 1 QC2.95 [2.37, 3.77]1.80-2.64 [-3.64, -1.91]3.46 [2.83, 4.28]19% [6%, 29%]31%54%+0.28+0.532026-08-05 → 2026-08-30
tmax12Znearest90d26 1 QC2.95 [2.32, 3.93]1.80-2.64 [-3.88, -1.76]3.46 [2.75, 4.40]19% [5%, 29%]31%54%+0.28+0.532026-08-05 → 2026-08-30
tmax12Znearest365d26 1 QC2.95 [2.24, 3.94]1.80-2.64 [-3.77, -1.73]3.46 [2.69, 4.39]19% [0%, 29%]31%54%+0.28+0.532026-08-05 → 2026-08-30
tmax12Znearestall26 1 QC2.95 [2.27, 4.01]1.80-2.64 [-3.85, -1.76]3.46 [2.73, 4.42]19% [0%, 29%]31%54%+0.28+0.532026-08-05 → 2026-08-30
tmin00Zbilinear30d26 1 QC2.54 [1.88, 3.16]2.43+1.50 [0.58, 2.52]3.31 [2.37, 4.12]31% [22%, 43%]54%69%+0.19+0.212026-08-05 → 2026-08-30
tmin00Zbilinear90d26 1 QC2.54 [1.77, 3.25]2.43+1.50 [0.56, 2.72]3.31 [2.20, 4.26]31% [21%, 44%]54%69%+0.19+0.212026-08-05 → 2026-08-30
tmin00Zbilinear365d26 1 QC2.54 [1.79, 3.28]2.43+1.50 [0.54, 2.82]3.31 [2.22, 4.29]31% [21%, 45%]54%69%+0.19+0.212026-08-05 → 2026-08-30
tmin00Zbilinearall26 1 QC2.54 [1.74, 3.28]2.43+1.50 [0.55, 2.71]3.31 [2.12, 4.27]31% [20%, 45%]54%69%+0.19+0.212026-08-05 → 2026-08-30
tmin00Znearest30d26 1 QC2.50 [1.97, 2.94]2.54+0.58 [-0.36, 1.59]3.08 [2.32, 3.68]19% [7%, 37%]50%73%+0.20+0.172026-08-05 → 2026-08-30
tmin00Znearest90d26 1 QC2.50 [1.89, 2.96]2.54+0.58 [-0.37, 1.77]3.08 [2.20, 3.78]19% [6%, 41%]50%73%+0.20+0.172026-08-05 → 2026-08-30
tmin00Znearest365d26 1 QC2.50 [1.88, 2.99]2.54+0.58 [-0.39, 1.86]3.08 [2.18, 3.78]19% [5%, 40%]50%73%+0.20+0.172026-08-05 → 2026-08-30
tmin00Znearestall26 1 QC2.50 [1.86, 2.97]2.54+0.58 [-0.39, 1.74]3.08 [2.13, 3.78]19% [5%, 43%]50%73%+0.20+0.172026-08-05 → 2026-08-30
tmin12Zbilinear30d26 1 QC2.60 [2.07, 3.10]2.34+1.38 [0.44, 2.33]3.18 [2.29, 4.00]19% [4%, 37%]46%73%+0.17+0.242026-08-05 → 2026-08-30
tmin12Zbilinear90d26 1 QC2.60 [2.02, 3.16]2.34+1.38 [0.33, 2.46]3.18 [2.20, 4.08]19% [0%, 38%]46%73%+0.17+0.242026-08-05 → 2026-08-30
tmin12Zbilinear365d26 1 QC2.60 [1.97, 3.15]2.34+1.38 [0.29, 2.51]3.18 [2.17, 4.07]19% [0%, 38%]46%73%+0.17+0.242026-08-05 → 2026-08-30
tmin12Zbilinearall26 1 QC2.60 [2.00, 3.16]2.34+1.38 [0.35, 2.46]3.18 [2.16, 4.10]19% [0%, 38%]46%73%+0.17+0.242026-08-05 → 2026-08-30
tmin12Znearest30d26 1 QC2.42 [2.01, 2.87]2.40+0.47 [-0.51, 1.41]2.95 [2.24, 3.60]19% [4%, 33%]50%77%+0.22+0.222026-08-05 → 2026-08-30
tmin12Znearest90d26 1 QC2.42 [1.91, 2.85]2.40+0.47 [-0.62, 1.51]2.95 [2.14, 3.63]19% [0%, 33%]50%77%+0.22+0.222026-08-05 → 2026-08-30
tmin12Znearest365d26 1 QC2.42 [1.88, 2.91]2.40+0.47 [-0.62, 1.57]2.95 [2.11, 3.71]19% [0%, 33%]50%77%+0.22+0.222026-08-05 → 2026-08-30
tmin12Znearestall26 1 QC2.42 [1.95, 2.90]2.40+0.47 [-0.62, 1.51]2.95 [2.16, 3.68]19% [0%, 32%]50%77%+0.22+0.222026-08-05 → 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 ECMWF AIFS Single at KEWR, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -6.32 °F2026-08-06: -4.57 °F2026-08-07: -6.57 °F2026-08-08: -3.64 °F2026-08-09: -2.11 °F2026-08-10: -0.64 °F2026-08-11: -1.56 °F2026-08-12: -4.09 °F2026-08-13: -3.26 °F2026-08-14: -4.57 °F2026-08-15: -5.86 °F2026-08-16: -2.61 °F2026-08-17: +2.43 °F2026-08-18: -3.17 °F2026-08-19: -5.26 °F2026-08-20: -0.69 °F2026-08-21: -5.72 °F2026-08-22: -3.63 °F2026-08-23: -3.07 °F2026-08-24: -4.86 °F2026-08-25: -3.72 °F2026-08-26: -4.05 °F2026-08-27: -2.15 °F2026-08-28: -4.93 °F2026-08-29: +0.78 °F2026-08-30: +0.51 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.51
2026-08-29+0.78
2026-08-28-4.93
2026-08-27-2.15
2026-08-26-4.05
2026-08-25-3.72
2026-08-24-4.86
2026-08-23-3.07
2026-08-22-3.63
2026-08-21-5.72
2026-08-20-0.69
2026-08-19-5.26
2026-08-18-3.17
2026-08-17+2.43
2026-08-16-2.61
2026-08-15-5.86
2026-08-14-4.57
2026-08-13-3.26
2026-08-12-4.09
2026-08-11-1.56
2026-08-10-0.64
2026-08-09-2.11
2026-08-08-3.64
2026-08-07-6.57
2026-08-06-4.57
2026-08-05-6.32

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KEWR, lead day 4-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 2 days-6 to -5 °F: 3 days-5 to -4 °F: 6 days-4 to -3 °F: 6 days-3 to -2 °F: 3 days-2 to -1 °F: 1 day-1 to 0 °F: 2 days0 to 1 °F: 2 days1 to 2 °F: 0 days2 to 3 °F: 1 day3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 3.63 · P90 |e| 5.79 °F-100+10 °Fn = 26 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
-7.00-6.002
-6.00-5.003
-5.00-4.006
-4.00-3.006
-3.00-2.003
-2.00-1.001
-1.00+0.002
+0.00+1.002
+1.00+2.000
+2.00+3.001
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+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
2026-08263.49 -3.20

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF AIFS Single has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
NCEP GFS 26 +0.90 [-0.14, 1.86] no
GraphCast (IFS init) 25 -1.14 [-2.11, -0.30] yes
ECMWF IFS HRES 20 +0.33 [-0.25, 1.25] no
Persistence (baseline) 26 -0.59 [-1.68, 0.24] no

Cite this page

ShortCastCheck, KEWR aifs_single lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KEWR/model/aifs_single/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KEWR (Newark Liberty), model aifs_single, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KEWR/model/aifs_single/lead/4/

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