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

New York Central Park · ECMWF AIFS Single · lead day 4

KNYC · 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 QC2.20 [1.70, 2.81]1.88-0.78 [-1.55, 0.05]2.64 [2.05, 3.20]27% [12%, 42%]54%69%+0.43+0.482026-08-05 → 2026-08-30
tmax00Zbilinear90d26 1 QC2.20 [1.70, 2.91]1.88-0.78 [-1.69, 0.38]2.64 [2.08, 3.31]27% [9%, 43%]54%69%+0.43+0.482026-08-05 → 2026-08-30
tmax00Zbilinear365d26 1 QC2.20 [1.67, 2.94]1.88-0.78 [-1.71, 0.43]2.64 [2.01, 3.35]27% [7%, 43%]54%69%+0.43+0.482026-08-05 → 2026-08-30
tmax00Zbilinearall26 1 QC2.20 [1.65, 2.95]1.88-0.78 [-1.78, 0.33]2.64 [1.98, 3.32]27% [10%, 43%]54%69%+0.43+0.482026-08-05 → 2026-08-30
tmax00Znearest30d26 1 QC2.05 [1.51, 2.66]1.94-0.37 [-1.15, 0.46]2.60 [1.94, 3.17]35% [20%, 48%]62%73%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearest90d26 1 QC2.05 [1.55, 2.75]1.94-0.37 [-1.32, 0.82]2.60 [1.99, 3.24]35% [18%, 47%]62%73%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearest365d26 1 QC2.05 [1.51, 2.79]1.94-0.37 [-1.34, 0.86]2.60 [1.96, 3.25]35% [19%, 50%]62%73%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearestall26 1 QC2.05 [1.48, 2.75]1.94-0.37 [-1.40, 0.76]2.60 [1.88, 3.25]35% [19%, 50%]62%73%+0.47+0.462026-08-05 → 2026-08-30
tmax12Zbilinear30d26 1 QC1.97 [1.55, 2.51]1.97-0.24 [-0.96, 0.43]2.44 [1.94, 2.96]31% [12%, 47%]58%77%+0.49+0.462026-08-05 → 2026-08-30
tmax12Zbilinear90d26 1 QC1.97 [1.54, 2.53]1.97-0.24 [-1.19, 0.58]2.44 [1.94, 3.00]31% [8%, 48%]58%77%+0.49+0.462026-08-05 → 2026-08-30
tmax12Zbilinear365d26 1 QC1.97 [1.51, 2.58]1.97-0.24 [-1.23, 0.67]2.44 [1.91, 3.05]31% [6%, 50%]58%77%+0.49+0.462026-08-05 → 2026-08-30
tmax12Zbilinearall26 1 QC1.97 [1.44, 2.58]1.97-0.24 [-1.21, 0.63]2.44 [1.83, 3.03]31% [5%, 50%]58%77%+0.49+0.462026-08-05 → 2026-08-30
tmax12Znearest30d26 1 QC2.00 [1.59, 2.45]2.01+0.19 [-0.55, 0.89]2.47 [1.98, 2.95]35% [17%, 50%]58%73%+0.48+0.452026-08-05 → 2026-08-30
tmax12Znearest90d26 1 QC2.00 [1.61, 2.50]2.01+0.19 [-0.74, 1.05]2.47 [2.00, 3.00]35% [14%, 52%]58%73%+0.48+0.452026-08-05 → 2026-08-30
tmax12Znearest365d26 1 QC2.00 [1.59, 2.54]2.01+0.19 [-0.78, 1.15]2.47 [2.00, 3.03]35% [12%, 52%]58%73%+0.48+0.452026-08-05 → 2026-08-30
tmax12Znearestall26 1 QC2.00 [1.51, 2.52]2.01+0.19 [-0.85, 1.08]2.47 [1.92, 3.02]35% [12%, 55%]58%73%+0.48+0.452026-08-05 → 2026-08-30
tmin00Zbilinear30d26 1 QC2.76 [1.88, 3.80]2.16+2.46 [1.43, 3.63]3.76 [2.40, 5.10]27% [12%, 47%]50%65%-0.18+0.102026-08-05 → 2026-08-30
tmin00Zbilinear90d26 1 QC2.76 [1.78, 3.91]2.16+2.46 [1.35, 3.71]3.76 [2.33, 5.22]27% [12%, 50%]50%65%-0.18+0.102026-08-05 → 2026-08-30
tmin00Zbilinear365d26 1 QC2.76 [1.78, 3.99]2.16+2.46 [1.29, 3.77]3.76 [2.32, 5.26]27% [10%, 50%]50%65%-0.18+0.102026-08-05 → 2026-08-30
tmin00Zbilinearall26 1 QC2.76 [1.78, 3.94]2.16+2.46 [1.30, 3.74]3.76 [2.34, 5.28]27% [11%, 50%]50%65%-0.18+0.102026-08-05 → 2026-08-30
tmin00Znearest30d26 1 QC2.85 [1.93, 3.91]2.19+2.59 [1.54, 3.77]3.87 [2.50, 5.21]23% [11%, 40%]50%65%-0.22+0.092026-08-05 → 2026-08-30
tmin00Znearest90d26 1 QC2.85 [1.81, 4.02]2.19+2.59 [1.48, 3.84]3.87 [2.43, 5.34]23% [11%, 44%]50%65%-0.22+0.092026-08-05 → 2026-08-30
tmin00Znearest365d26 1 QC2.85 [1.83, 4.10]2.19+2.59 [1.41, 3.92]3.87 [2.42, 5.37]23% [9%, 43%]50%65%-0.22+0.092026-08-05 → 2026-08-30
tmin00Znearestall26 1 QC2.85 [1.81, 4.05]2.19+2.59 [1.42, 3.86]3.87 [2.44, 5.39]23% [11%, 44%]50%65%-0.22+0.092026-08-05 → 2026-08-30
tmin12Zbilinear30d26 1 QC2.55 [1.70, 3.51]1.87+2.37 [1.36, 3.41]3.52 [2.07, 4.89]27% [13%, 43%]54%73%-0.09+0.222026-08-05 → 2026-08-30
tmin12Zbilinear90d26 1 QC2.55 [1.58, 3.61]1.87+2.37 [1.22, 3.49]3.52 [1.86, 4.97]27% [12%, 45%]54%73%-0.09+0.222026-08-05 → 2026-08-30
tmin12Zbilinear365d26 1 QC2.55 [1.42, 3.68]1.87+2.37 [1.28, 3.55]3.52 [1.61, 5.02]27% [12%, 50%]54%73%-0.09+0.222026-08-05 → 2026-08-30
tmin12Zbilinearall26 1 QC2.55 [1.48, 3.57]1.87+2.37 [1.25, 3.53]3.52 [1.63, 5.00]27% [12%, 48%]54%73%-0.09+0.222026-08-05 → 2026-08-30
tmin12Znearest30d26 1 QC2.65 [1.77, 3.63]1.90+2.50 [1.45, 3.54]3.64 [2.17, 5.01]27% [13%, 43%]50%73%-0.13+0.212026-08-05 → 2026-08-30
tmin12Znearest90d26 1 QC2.65 [1.63, 3.72]1.90+2.50 [1.32, 3.63]3.64 [1.96, 5.09]27% [12%, 45%]50%73%-0.13+0.212026-08-05 → 2026-08-30
tmin12Znearest365d26 1 QC2.65 [1.46, 3.79]1.90+2.50 [1.35, 3.68]3.64 [1.66, 5.15]27% [12%, 50%]50%73%-0.13+0.212026-08-05 → 2026-08-30
tmin12Znearestall26 1 QC2.65 [1.52, 3.70]1.90+2.50 [1.32, 3.63]3.64 [1.70, 5.13]27% [12%, 48%]50%73%-0.13+0.212026-08-05 → 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 KNYC, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -4.72 °F2026-08-06: -0.59 °F2026-08-07: -3.31 °F2026-08-08: -0.4 °F2026-08-09: +1.01 °F2026-08-10: +3.44 °F2026-08-11: +0.56 °F2026-08-12: -0.82 °F2026-08-13: -1.12 °F2026-08-14: -2.21 °F2026-08-15: -4.5 °F2026-08-16: -1.74 °F2026-08-17: +5.65 °F2026-08-18: -3.84 °F2026-08-19: -1.95 °F2026-08-20: -1.24 °F2026-08-21: -3.08 °F2026-08-22: -0.89 °F2026-08-23: -0.74 °F2026-08-24: -2.11 °F2026-08-25: -1.3 °F2026-08-26: -1.69 °F2026-08-27: +0.57 °F2026-08-28: -2.47 °F2026-08-29: +4.21 °F2026-08-30: +2.96 °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+2.96
2026-08-29+4.21
2026-08-28-2.47
2026-08-27+0.57
2026-08-26-1.69
2026-08-25-1.30
2026-08-24-2.11
2026-08-23-0.74
2026-08-22-0.89
2026-08-21-3.08
2026-08-20-1.24
2026-08-19-1.95
2026-08-18-3.84
2026-08-17+5.65
2026-08-16-1.74
2026-08-15-4.50
2026-08-14-2.21
2026-08-13-1.12
2026-08-12-0.82
2026-08-11+0.56
2026-08-10+3.44
2026-08-09+1.01
2026-08-08-0.40
2026-08-07-3.31
2026-08-06-0.59
2026-08-05-4.72

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KNYC, 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: 0 days-6 to -5 °F: 0 days-5 to -4 °F: 2 days-4 to -3 °F: 3 days-3 to -2 °F: 3 days-2 to -1 °F: 6 days-1 to 0 °F: 5 days0 to 1 °F: 2 days1 to 2 °F: 1 day2 to 3 °F: 1 day3 to 4 °F: 1 day4 to 5 °F: 1 day5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 1.84 · P90 |e| 4.35 °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
-7.00-6.000
-6.00-5.000
-5.00-4.002
-4.00-3.003
-3.00-2.003
-2.00-1.006
-1.00+0.005
+0.00+1.002
+1.00+2.001
+2.00+3.001
+3.00+4.001
+4.00+5.001
+5.00+6.001
+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
2026-08262.20 -0.78

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 -1.98 [-3.03, -0.94] yes
GraphCast (IFS init) 25 -0.49 [-0.93, -0.04] yes
ECMWF IFS HRES 20 -1.14 [-2.07, 0.57] no
Persistence (baseline) 26 -1.65 [-2.94, -0.22] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), 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/KNYC/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