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

New York Central Park · GraphCast (IFS init) · lead day 1

KNYC · graphcast_ifs · lead 1

Target day = initialization date + 1 day. 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, GRAP_v100, starting 2026-01-01 — 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
tmax00Zbilinear30d27 1 QC2.07 [1.53, 2.60]1.49-1.69 [-2.36, -0.97]2.53 [1.84, 3.07]30% [14%, 46%]59%78%+0.17+0.382026-08-02 → 2026-08-30
tmax00Zbilinear90d27 1 QC2.07 [1.49, 2.63]1.49-1.69 [-2.36, -0.90]2.53 [1.70, 3.07]30% [11%, 48%]59%78%+0.17+0.382026-08-02 → 2026-08-30
tmax00Zbilinear365d33 1 QC1.99 [1.46, 2.46]1.55-1.61 [-2.20, -0.87]2.53 [1.87, 3.01]33% [17%, 50%]64%79%+0.29+0.452026-01-02 → 2026-08-30
tmax00Zbilinearall33 1 QC1.99 [1.39, 2.50]1.55-1.61 [-2.21, -0.83]2.53 [1.77, 2.97]33% [16%, 50%]64%79%+0.29+0.452026-01-02 → 2026-08-30
tmax00Znearest30d27 1 QC2.05 [1.48, 2.59]1.54-1.60 [-2.30, -0.86]2.52 [1.81, 3.06]30% [14%, 46%]63%78%+0.18+0.362026-08-02 → 2026-08-30
tmax00Znearest90d27 1 QC2.05 [1.41, 2.66]1.54-1.60 [-2.29, -0.79]2.52 [1.59, 3.08]30% [11%, 48%]63%78%+0.18+0.362026-08-02 → 2026-08-30
tmax00Znearest365d33 1 QC1.96 [1.40, 2.48]1.59-1.50 [-2.11, -0.74]2.50 [1.79, 2.99]33% [17%, 50%]67%79%+0.30+0.432026-01-02 → 2026-08-30
tmax00Znearestall33 1 QC1.96 [1.33, 2.51]1.59-1.50 [-2.13, -0.71]2.50 [1.71, 2.95]33% [16%, 50%]67%79%+0.30+0.432026-01-02 → 2026-08-30
tmax12Zbilinear30d27 1 QC1.85 [1.47, 2.20]1.30-1.47 [-2.09, -0.81]2.20 [1.79, 2.56]30% [15%, 47%]56%81%+0.26+0.462026-08-02 → 2026-08-30
tmax12Zbilinear90d27 1 QC1.85 [1.41, 2.26]1.30-1.47 [-2.11, -0.75]2.20 [1.69, 2.59]30% [12%, 50%]56%81%+0.26+0.462026-08-02 → 2026-08-30
tmax12Zbilinear365d32 1 QC1.90 [1.47, 2.33]1.32-1.57 [-2.18, -0.88]2.33 [1.83, 2.77]28% [13%, 46%]56%81%+0.28+0.502026-01-02 → 2026-08-30
tmax12Zbilinearall32 1 QC1.90 [1.43, 2.31]1.32-1.57 [-2.13, -0.87]2.33 [1.78, 2.76]28% [12%, 45%]56%81%+0.28+0.502026-01-02 → 2026-08-30
tmax12Znearest30d27 1 QC1.82 [1.43, 2.19]1.33-1.38 [-2.01, -0.71]2.17 [1.75, 2.52]33% [17%, 50%]56%78%+0.27+0.452026-08-02 → 2026-08-30
tmax12Znearest90d27 1 QC1.82 [1.35, 2.26]1.33-1.38 [-2.01, -0.63]2.17 [1.63, 2.54]33% [13%, 57%]56%78%+0.27+0.452026-08-02 → 2026-08-30
tmax12Znearest365d32 1 QC1.86 [1.43, 2.30]1.34-1.46 [-2.07, -0.76]2.27 [1.79, 2.69]34% [15%, 57%]59%78%+0.30+0.492026-01-02 → 2026-08-30
tmax12Znearestall32 1 QC1.86 [1.38, 2.25]1.34-1.46 [-2.04, -0.75]2.27 [1.71, 2.66]34% [16%, 56%]59%78%+0.30+0.492026-01-02 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.69 [1.08, 2.35]1.54+0.84 [0.14, 1.46]2.31 [1.50, 2.93]52% [31%, 72%]70%78%+0.36+0.412026-08-02 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.69 [1.04, 2.47]1.54+0.84 [-0.17, 1.42]2.31 [1.41, 3.02]52% [27%, 73%]70%78%+0.36+0.412026-08-02 → 2026-08-30
tmin00Zbilinear365d33 1 QC2.01 [1.22, 2.94]2.00+0.08 [-1.96, 1.27]2.78 [1.74, 3.74]48% [29%, 67%]64%73%+0.26+0.272026-01-02 → 2026-08-30
tmin00Zbilinearall33 1 QC2.01 [1.21, 2.94]2.00+0.08 [-1.78, 1.18]2.78 [1.74, 3.73]48% [28%, 68%]64%73%+0.26+0.272026-01-02 → 2026-08-30
tmin00Znearest30d27 1 QC1.76 [1.17, 2.37]1.51+1.02 [0.32, 1.61]2.35 [1.58, 2.94]37% [22%, 52%]70%78%+0.33+0.422026-08-02 → 2026-08-30
tmin00Znearest90d27 1 QC1.76 [1.10, 2.48]1.51+1.02 [0.03, 1.58]2.35 [1.44, 3.03]37% [23%, 52%]70%78%+0.33+0.422026-08-02 → 2026-08-30
tmin00Znearest365d33 1 QC2.04 [1.30, 2.90]1.99+0.26 [-1.75, 1.44]2.76 [1.77, 3.63]36% [24%, 50%]67%73%+0.25+0.272026-01-02 → 2026-08-30
tmin00Znearestall33 1 QC2.04 [1.27, 2.89]1.99+0.26 [-1.58, 1.35]2.76 [1.76, 3.63]36% [23%, 51%]67%73%+0.25+0.272026-01-02 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.52 [0.87, 2.27]1.49+0.67 [0.02, 1.22]2.24 [1.33, 2.91]56% [41%, 70%]78%78%+0.42+0.432026-08-02 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.52 [0.88, 2.40]1.49+0.67 [-0.23, 1.20]2.24 [1.28, 3.02]56% [38%, 69%]78%78%+0.42+0.432026-08-02 → 2026-08-30
tmin12Zbilinear365d32 1 QC1.88 [1.03, 3.00]1.88-0.03 [-2.01, 1.09]2.73 [1.61, 3.82]50% [30%, 66%]72%72%+0.32+0.322026-01-02 → 2026-08-30
tmin12Zbilinearall32 1 QC1.88 [1.06, 3.02]1.88-0.03 [-1.81, 1.06]2.73 [1.62, 3.83]50% [30%, 65%]72%72%+0.32+0.322026-01-02 → 2026-08-30
tmin12Znearest30d27 1 QC1.58 [0.91, 2.29]1.48+0.86 [0.23, 1.41]2.29 [1.41, 2.96]52% [30%, 70%]74%81%+0.40+0.442026-08-02 → 2026-08-30
tmin12Znearest90d27 1 QC1.58 [0.92, 2.43]1.48+0.86 [-0.02, 1.39]2.29 [1.33, 3.07]52% [28%, 68%]74%81%+0.40+0.442026-08-02 → 2026-08-30
tmin12Znearest365d32 1 QC1.89 [1.06, 2.92]1.86+0.17 [-1.78, 1.28]2.72 [1.64, 3.68]47% [24%, 64%]69%75%+0.31+0.322026-01-02 → 2026-08-30
tmin12Znearestall32 1 QC1.89 [1.07, 2.93]1.86+0.17 [-1.59, 1.25]2.72 [1.66, 3.72]47% [23%, 64%]69%75%+0.31+0.322026-01-02 → 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 GraphCast (IFS init) at KNYC, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -2.75 °F2026-08-03: +1.01 °F2026-08-04: -3.33 °F2026-08-05: -4.36 °F2026-08-06: -2.48 °F2026-08-07: -4.36 °F2026-08-08: +0.35 °F2026-08-09: +0.79 °F2026-08-10: +2.15 °F2026-08-11: +0.19 °F2026-08-12: -1.43 °F2026-08-13: -0.56 °F2026-08-14: -0.53 °F2026-08-15: -3.75 °F2026-08-16: -2.45 °F2026-08-17: +0.71 °F2026-08-18: -4.74 °F2026-08-19: -1.93 °F2026-08-20: -5.83 °F2026-08-21: -1.68 °F2026-08-22: -0.89 °F2026-08-23: -1.22 °F2026-08-24: -1.97 °F2026-08-25: -1.89 °F2026-08-26: -2.11 °F2026-08-29: -0.7 °F2026-08-30: -1.77 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.77
2026-08-29-0.70
2026-08-28—
2026-08-27—
2026-08-26-2.11
2026-08-25-1.89
2026-08-24-1.97
2026-08-23-1.22
2026-08-22-0.89
2026-08-21-1.68
2026-08-20-5.83
2026-08-19-1.93
2026-08-18-4.74
2026-08-17+0.71
2026-08-16-2.45
2026-08-15-3.75
2026-08-14-0.53
2026-08-13-0.56
2026-08-12-1.43
2026-08-11+0.19
2026-08-10+2.15
2026-08-09+0.79
2026-08-08+0.35
2026-08-07-4.36
2026-08-06-2.48
2026-08-05-4.36
2026-08-04-3.33
2026-08-03+1.01
2026-08-02-2.75

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KNYC, lead day 1-10 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: 2 days-5 to -4 °F: 3 days-4 to -3 °F: 2 days-3 to -2 °F: 4 days-2 to -1 °F: 8 days-1 to 0 °F: 6 days0 to 1 °F: 5 days1 to 2 °F: 2 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| 1.68 · P90 |e| 4.36 °F-100+10 °Fn = 33 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
-6.00-5.002
-5.00-4.003
-4.00-3.002
-3.00-2.004
-2.00-1.008
-1.00+0.006
+0.00+1.005
+1.00+2.002
+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
2026-08272.07 -1.69
2026-0161.63 -1.27

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 33
GraphCast (IFS init)2026-01-02 → 2026-08-30 32
GraphCast (IFS init)2026-01-02 → 2026-08-30 32

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 27 +0.81 [0.20, 1.38] yes
Aurora (GFS init) 1 +1.53 [1.53, 1.53] yes
Aurora (IFS init) 2 +0.96 [0.31, 1.60] yes
FourCastNet v2 (GFS init) 1 +1.16 [1.16, 1.16] yes
FourCastNet v2 (IFS init) 2 -0.78 [-2.49, 0.94] no
NCEP GFS 27 -1.71 [-3.56, -0.24] yes
GraphCast (GFS init) 1 -0.41 [-0.41, -0.41] yes
ECMWF IFS HRES 21 -0.88 [-2.30, 0.21] no
Pangu-Weather (GFS init) 1 -2.67 [-2.67, -2.67] yes
Pangu-Weather (IFS init) 2 -2.48 [-2.83, -2.13] yes
Persistence (baseline) 27 -0.41 [-1.40, 0.23] no

Cite this page

ShortCastCheck, KNYC graphcast_ifs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KNYC/model/graphcast_ifs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), model graphcast_ifs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KNYC/model/graphcast_ifs/lead/1/

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